June is an exciting month for dahlias, and it’s one of my favorite times in the garden. I love growing dahlias because they change so fast this time of year – suddenly plants are taller, fuller, and, in warmer parts of the US, some are already starting to form buds. It’s also the point when good dahlia care starts to pay off later in summer.

A nostalgic favorite, growing dahlias have become hugely popular again in recent years, and it’s easy to understand why. There are so many beautiful dahlia types to grow, from small pompon and waterlily varieties to dramatic dinnerplate and cactus dahlias. They also come in almost every color imaginable, making them one of the most versatile summer flowers for US gardens.

A few simple jobs in June – like staking, feeding, watering deeply, and pinching back stems – can make the difference between weak plants with a few flowers and strong, bloom-filled dahlias that keep going right into fall.

1. Plant Out Tubers and Young Plants

If you haven’t had the chance to plant dahlia tubers yet because of late spring weather, early June is usually your last good window in cooler parts of the US. Dahlias love warmth and don’t do well in cold, soggy soil, so it’s often better to wait until overnight temperatures are consistently mild before planting.

Choose a sunny spot with rich, well-draining soil. Most dahlias need at least six hours of direct sun each day, although gardeners in hotter southern states may find plants benefit from a little afternoon shade during peak summer heat.

When you plant dahlia tubers, set them around 4 to 6 inches deep and leave about 2 feet between taller varieties to improve airflow later in the season. Water them in well, then avoid overwatering until you see strong new growth, since overly wet soil can quickly rot young tubers.

If you’re still shopping, many of the best places to buy dahlia tubers include specialist flower farms, local garden centers, and online dahlia growers, which often offer a much wider range of dahlia types than big-box stores.

2. Stake Tall Varieties Early

Staking dahlias is one of those jobs that’s easy to delay – until a summer storm rolls through and flattens your plants overnight. By this time of the year, many dahlias are growing fast, and their hollow stems can snap surprisingly easily once the flowers start getting larger and heavier. Getting the right support in place early makes a huge difference later in the season.

I always try to add stakes while plants are still fairly small. It’s much easier, and you avoid damaging tubers or roots trying to force supports into the ground later on. Bamboo canes work well for individual plants, especially in garden borders where you want supports to blend in naturally. As stems grow, loosely tie them in with soft twine or plant ties so they still have room to move.

For taller or heavier dahlias, tomato cages can be a lifesaver too, particularly in containers or windy gardens where plants need extra stability. The bigger the blooms, the more support plants usually need by midsummer.

Two useful options I’d recommend are the Heavy Duty Bamboo Garden Stakes from Amazon for staking individual stems discreetly, and the Adjustable Tomato Cage Trellis from Amazon for supporting larger, top-heavy plants in pots or borders.

3. Pinch Out Growing Tips for Bushier Plants

Once dahlias reach around 12 to 16 inches tall, it’s time to pinch out dahlias – one of those simple but surprisingly important jobs that really shape how the plants perform later on. It can feel a bit counterintuitive to cut back healthy growth just as everything is taking off, but it makes a big difference.

By removing the central growing tip, you encourage the plant to branch out instead of shooting upward on a single stem. The result is a fuller, sturdier plant with many more blooms once summer really gets going.

All you need to do is pinch or snip the main stem just above a set of leaves. You might lose a week or so of early flowers, but the payoff is a much better display overall. Most taller border and cutting dahlia types benefit most from this, while smaller bedding varieties usually don’t need it.

For this job, a clean, sharp tool makes it much easier and helps avoid damaging tender stems. A popular choice with gardeners is the Fiskars Micro-Tip Pruning Snips, which are ideal for precise work when you pinch out dahlias or trim small side shoots without crushing the plant.

4. Start Feeding Regularly

June is the month when dahlias start growing quickly and using up nutrients fast, so this is the point where it really pays to fertilize dahlias regularly. At this stage, I usually start with a balanced liquid fertilizer every couple of weeks while the plants focus on building strong leaves and stems.

Once buds begin to form later in the season, I switch to a higher-potassium feed to support stronger flowering and better blooms. A good option many US gardeners use is Miracle-Gro Water Soluble Bloom Booster Flower Food from The Home Depot, which is designed to encourage more flowers rather than leafy growth.

It’s worth being careful with high-nitrogen fertilizers at this stage, since they tend to push lots of foliage but fewer blooms – not what most of us want from dahlias.

I also like to top things off with a layer of compost or well-rotted mulch around the base of plants. It helps the soil retain moisture during hot spells and gradually improves fertility as the season progresses.

5. Water Deeply During Dry Spells

Young dahlias can dry out surprisingly fast in early summer, especially during heat waves or windy spells. When that happens, they can stall quickly, so keeping an eye on moisture levels really helps keep dahlias blooming steadily later in the season.

Instead of light watering every day, it’s better to give plants a deep soak once or twice a week, depending on rainfall and temperature. This encourages roots to grow deeper into the soil, which leads to stronger, more resilient plants as summer goes on.

Container-grown dahlias are a different story – they usually need more frequent watering, particularly in hot US climates where pots can dry out in a single day.

Whenever you can, water at the base of the plant in the early morning. Avoid wetting the foliage late in the day, since that can lead to mildew and other fungal issues once humidity builds in midsummer.

6. Watch for Slugs, Snails, and Aphids

Fresh dahlia growth in June is a magnet for pests, and it’s something most gardeners run into sooner or later. Slugs and snails are usually the first troublemakers – they can strip tender new shoots almost overnight after rain.

It helps to check plants regularly, especially early in the morning or late in the evening when damage is easiest to spot. When it comes to dahlia pests, many gardeners in the US lean on simple, wildlife-friendly methods like barriers, traps, or hand-picking rather than reaching straight for chemicals.

Aphids are another common issue on soft new growth this time of year. The good news is that healthy gardens often balance things out naturally once ladybugs and other beneficial insects arrive. If populations do build up, a gentle but effective option many American gardeners use is Bonide Insecticidal Soap from The Home Depot, which works well for knocking back aphids without being harsh on tender growth.

Good spacing between plants also helps improve airflow, which in turn reduces the risk of fungal problems later in summer.

7. Take Basal Cuttings From Vigorous Plants

If you’re hoping to grow your dahlia collection without spending more money, June is still a good time to take basal cuttings from healthy, fast-growing plants. Choose nonflowering shoots around 3 to 4 inches long and remove them cleanly near the base. Place them into small pots filled with moist potting mix and keep them somewhere warm and lightly humid while roots develop. Not every cutting will take, but successful ones can grow into flowering plants by late summer and provide extra tubers to overwinter for next year.

June is an important month for dahlias. A bit of attention now, especially with staking, feeding, and pinching back stems, makes a noticeable difference later on, leading to stronger plants and a much longer flowering season.

And once dahlias hit their peak in July and August, it’s easy to see why they’ve become so popular in US gardens again. Few plants can compete with their range of colors, shapes, and sizes, and all that variety – from different dahlia types to bold, statement blooms – more than justifies the extra care they need in early summer.

April is a good time to start thinking about your dahlias again. After sitting dormant for months, this is the point where tubers are gently brought back into growth or potted up to get a head start on the season.

It might not look especially exciting yet, but if you’re wondering what to do with dahlias in April, this is the stage that quietly sets everything up. What you do now has a direct impact on how strong, healthy, and floriferous your plants will be later on.

It’s also a good time to take stock of the types of dahlias you’re growing. Taller, more vigorous varieties will need a bit more thought early on, while smaller types are often more forgiving. Either way, if you want to grow dahlias well, the key is not to rush them. They respond best to steady warmth, good light, and a light touch with watering.

Get that balance right now, and by the time summer arrives, you’ll have dahlia plants that feel robust, well-shaped, and ready to shine.

1. Check Your Tubers Now Before Growth Begins

If you lifted dahlias last year, it’s worth taking a bit of time now to go through the tubers properly before you plant dahlia tubers or pot them up. Healthy ones should feel firm and slightly plump to the touch. If anything feels soft, hollow, or shows signs of rot or mold, it’s unlikely to come back and is best discarded.

This is also a good moment to divide larger clumps if you need to. As long as each section has at least one visible growing eye, it has the potential to become a new plant. It’s an easy way to build your collection, but it does reward a gentle approach – handle them carefully, as damage at this stage can set things back before they’ve even had a chance to get going.

2. Pot Up Tubers Now to Get Ahead of the Season

If there’s one job that really sets dahlias up for success in April, it’s potting up tubers and bringing them into gentle growth under cover. It gives you far more control over conditions and, in most cases, leads to earlier flowering and stronger, more reliable plants. It’s also the easiest way to grow dahlias in pots if you’re short on space or simply want a more manageable start to the season.

As Rachel Bull, Head of Gardens at Homes & Gardens, explains, April is all about giving dahlias the right start without overcomplicating things: ‘Mid-April is when I always start to pot up my dahlia tubers, ready to encourage the first signs of growth before planting them out into the cutting beds later in the year. I always use a multi-purpose, peat-free potting mix, and I mix in this Harris Premium Horticultural Grade Perlite from Amazon to improve drainage. Dahlia tubers do not like being waterlogged, so the better the drainage in your pots, the better your results. I plant with the tubers facing down into the soil, and not too deep.'

‘My top tip is to leave a small section of the stalk exposed so light can reach it and help trigger strong new growth. I keep potted dahlias in a frost-free, bright spot – often a cold frame like this wooden portable version from Wayfair – where they’re sheltered but still get plenty of light. From there, I water lightly and consistently until they’re ready to move outside in around 6–8 weeks.’

What stands out most is the restraint. Everything is kept light, well-drained, and controlled – nothing rushed or overdone, just the right conditions to let the plants wake up at their own pace.

3. Water Lightly to Avoid Setbacks

It’s easy to assume new growth needs plenty of water, but dahlias are actually the opposite early on. Overwatering in April is one of the quickest ways to lose tubers before they’ve properly gotten going. Aim for compost that’s just lightly moist – damp to the touch, but never wet. As shoots begin to appear and growth picks up, you can increase watering gradually, but even then, it’s about consistency rather than quantity.

4. Hold Off Planting Outside Until Conditions Are Right

Even if you can see shoots in April, it’s still too early to plant dahlias outdoors in most areas. Soil temperatures are usually still on the cool side, and a late frost can undo weeks of careful progress overnight. It’s far safer to keep them under cover for now and wait until late spring, when conditions have properly warmed up. A bit of patience at this stage really does pay off later in the season.

5. Plan Your Garden Display and Support Early

While your dahlias are still in pots, it’s worth planning ahead for their final position in the garden. They perform best in a sunny spot with some shelter from strong winds, planted into well-drained, fertile soil where they can establish without competition or stress.

It’s helpful at this stage to think about planting companions. Consider what to grow with dahlias to enhance the display and support a long season of interest, while also being mindful of what to never grow with dahlias – particularly anything that will overshadow them, compete too heavily for nutrients, or crowd their space as they develop.

It’s also the right moment to think about structural support. Taller varieties will almost certainly need staking later in the season, so planning this early means you can put supports in place without disturbing roots once the plants are actively growing.

Shop Dahlias Care for April

April with dahlias is a quiet month, but it’s doing most of the work behind the scenes. This is the time to check tubers, pot them up carefully, keep watering restrained, and resist the temptation to move them outdoors too soon.

Handled well, this early stage sets everything up – stronger plants, better natural structure, and the generous, long-lasting summer display that helps keep dahlias blooming for weeks on end.

Spring might have only just begun, but if you're a keen gardener, you're likely planning ahead – and you'll know that dahlia season will be here in no time. Now is the time to stock up on tubers, so if you haven't already, we have curated our top picks of where to buy them from.

Blooming from late summer until the fall, growing dahlias can be a wonderful addition to your garden. Dahlia tubers are a little different from bulbs; they serve as the 'storage' root for each plant, carrying water and nutrients. You can get as many as ten 'baby' plants from a single one; you'll just need to know where to find high-quality tubers.

Luckily, we've pulled together the ultimate guide to dahlia tubers. From Amazon's varied selection of dahlia tubers to boutique retailers like Eden Brothers, these are the very best places to buy dahlia tubers – so that you can create a vibrant garden come summertime.

1. Eden Brothers

Eden Brothers offers a dizzying array of bulbs and seeds, and it doesn't just sell flowers – you can also shop herb seeds, vegetable seeds, and a number of rare seeds, too.

The brand caters to home gardeners, wholesalers, and local farmers, and everything is hand-picked and shipped from North Carolina.

When it comes to dahlia tubers, you can filter your search by plant type, lifecycle, and height, and you can also search for specific colors. Bestselling varieties include cafe au lait dahlias (a pale beige flower that's beloved by florists) and labyrinth dahlias (a peach-colored flower with narrow, feathery petals).

Eden Brothers is also known for its mixed tubers; the jewel-toned old rose dahlia mix is particularly popular, alongside the uplifting strawberry fields dahlia mix.

2. Amazon

While you'll likely have shopped for tools and gardening supplies on Amazon, the platform might not be your first choice for seeds and bulbs – but Amazon does, in fact, offer many different types of dahlias.

I'd head to Amazon if you're looking for something speedy and affordable. Many dahlia tubers are priced at around $20, and you can also pick up seeds if you want to try growing dahlias from seed. (This zinnia dahlia seed mix is just $7.99 right now.)

You can search by seller for a little extra reassurance, and check out the reviews for each set of tubers to get growing tips from fellow gardeners. (Plus, Amazon happens to be one of the best places to buy houseplants, if you want to expand your indoor garden, too.)

3. Walmart

Walmart is another unlikely place to find dahlia tubers, but it offers an impressive selection.

You'll spot plenty of popular varieties, alongside a range of more unusual dahlias. (The peach and white frost nip dahlias are particularly gorgeous.)

Walmart also sells an assortment of mixed dahlia tubers, if you fancy bringing some surprise to your garden this summer.

4. Russells Mills Flower Co

Based in Southern Massachusetts, Russells Mills Flower Company is one of the largest dahlia growers in the US.

As a family-run business, it champions locally-grown flowers; you can shop exclusive tubers, buy in bulk, or browse bestsellers. (Right now, pale pink coralie dahlias are a favorite among shoppers.)

If you want to give your dahlias an extra boost, you can also pick up supplies including specially-formulated fertilizer and dahlia potting soil.

5. The Home Depot

The Home Depot is another reliable retailer, and it has plenty of dahlia tubers to explore – but just like Amazon and Walmart, it also sells seeds (and live plants) if you prefer.

You can find mixed tubers, classic dahlias, and a few rare varieties at Home Depot. There's an almost overwhelming amount of choice, though many tubers are provided by the same retailer. You can also filter by color, if you're after something specific.

6. Burpee

Burpee is a failsafe source of herbs, fruits, vegetables and plants, but it also has an enormous range of flowers, from seeds to bulbs and tubers.

When it comes to dahlias, Burpee's selection is smaller than other retailers, but there are plenty of show-stoppers.

You can choose a mix, or stick to your favorites. You'll find classic varieties along with some more extravagant options.

Looking for more dahlia tips? We asked experts how to fertilize dahlias properly – and how to pinch out dahlias, to help you get more flowers.

And if you love inspiring garden ideas, outdoor advice, and the latest news, why not sign up for our newsletter and get the latest features delivered straight to your inbox?

If you ask a flower grower the secret to incredible dahlia displays year-after-year, many will tell you it's lifting each and every tuber to store away carefully and replant in spring. But, this only works if proper storage is in place, otherwise you may find you're left with mushy dahlia tubers.

The truth is overwintering dahlias requires careful preparation and specific storage requirements, much like storing bulbs. They turn mushy when the storage set-up has allowed excess moisture in. At the same time, you don't want to let your tubers dry out, as this can dehydrate and shrivel them.

Here, gardening experts share exactly why this happens and what you can do to prevent mushy dahlia tubers to ensure an epic floral display next summer.

What Causes Dahlia Tubers to Go Mushy?

'Mushy tubers are the result of moisture penetrating the tuber without benefit of any top growth that needs the moisture,' summarizes gardening expert Lorraine Ballato.

Essentially, because tubers don't have any growth and are dormant in winter, isn't needed in the same way as when they're planted in the ground and actively growing.

'So, the moisture just stays there and eventually rots the tuber,' Lorraine explains.

You'll be able to tell if you have mushy dahlia tubers by simply picking them up and giving them a soft squeeze. They shouldn't be easy to indent and shouldn't appear wet, or have an unpleasant smell.

'Tubers that weren’t allowed to dry and cure properly before storage can also retain excess moisture,' says gardening expert Michael Clarke.

It isn't just excessive moisture behind mushy dahlia tubers, however, as improper ventilation and the wrong temperature are also key factors.

'Freezing temperatures can rupture cell walls, causing the tubers to collapse once they thaw. Overly warm temperatures can likewise encourage premature sprouting and decay,' Michael says.

'If tubers touch when they're stored or are sealed inside plastic, moisture and heat can get trapped leading to rot,' he adds.

This can even cause rot to spread among tubers, resulting in your entire stock being wiped out.

For this reason, Lorraine advises the following for storing dahlia tubers:

'Properly dry the tubers before they're stored,' she says. You can do this by brushing off dirt and letting them air-dry somewhere cool, dark, and well-ventilated.

'Use vermiculite (available from Amazon), perlite, which you can find at Walmart), or slightly dampened peat moss, from Amazon to pack tubers into a ventilated storage, like a crate. You don't want them to dry out entirely in storage, and these materials retain sufficient moisture,' says Lorraine.

As for location, keep tubers somewhere cool and dark, like an unheated garage or shed, ideally maintaining a temperature between 50-60°F. You should also check on stored bulbs and tubers once a month during winter, removing any rotting plant material to prevent spreading.

Can You Save Mushy Dahlia Tubers?

It is possible to save mushy dahlia tubers, depending on how far gone the problem is.

If only part of the tuber is rotting, you can carefully cut away the bad parts (with this sharp garden knife from Amazon), leaving just healthy, firm flesh.

You should allow the wounds to dry before placing them in storage again. The tubers will form a protective callous when drying.

However, if your tubers are entirely mushy and have a very unpleasant smell, it's unlikely they're viable and you should dispose of them immediately.

FAQs

How Can I Rehydrate Dahlia Tubers?

If your dahlia tubers have shrivelled from dehydration, soak them in room temperature water for just a couple of hours. Avoid soaking for much longer because it may cause rotting. You should then let them air-dry sufficiently (when the outer skin is tough) before returning them to proper storage.

In some regions, you don't have to lift dahlia tubers at all. Those living in US hardiness zone 7 and above can generally get away with leaving dahlia tubers in the ground, simply covering them with a generous layer of mulch. However, if you live in the harshest climes, you can lift and wrap dahlia tubers in burlap over winter to keep them in viable condition before replanting.

Shop Beautiful Gardening Accessories

Temperatures are beginning to plummet across certain parts of the country, and very soon it will be time to lift and store your dahlia tubers.

Overwintering dahlias isn’t a one size fits all approach. Whilst I am more in the camp of ‘you don’t need to dig up your dahlias’, and prefer to cover tubers in a thick mulch, there are many instances where you must dig up tubers to ensure they survive the winter. The main reasons to lift them are if you live in USDA hardiness zones 1-6 or if you are growing your dahlias in pots. These ones need to be dug up to properly protect them from frost and rotting in soggy soil.

I grow a lot of dahlias in pots on my patio, and last winter, after several years of failing, I tried a new method of storing them by wrapping the tubers in burlap sacks instead of leaving them in crates of moss. Here, I’ve detailed exactly why it works and how to do it, so you can be sure of new shoots the following May from each and every one of your tubers.

What you need to store dahlias properly over winter

The reason we tend to dig up dahlias and store them out of the soil over winter is to keep them dry and frost-free, and prevent them from rotting, as both conditions can damage and often kill off tubers.

If you look for advice online on the best way to store tubers, you will get a vast array of different options presented to you, but do they all work effectively?

In previous years, I always thought the way you had to store dahlia tubers was in my potting shed in trays of shallow compost or moss. But every year when I came to wake them up there were some that had gone moldy or mushy, and clearly were no longer viable.

My garden building is really old and, as is often the case with these structures, a bit damp. And these conditions, combined with moisture-loving moss, didn't do my tubers any favors.

Last year, however, I switched up my technique. Once I had cleaned the soil off my tubers and let them dry out for a few days, I wrapped each one separately in a square of burlap fabric, before placing in a crate to store over winter.

I simply cut squares of fabric from a big burlap roll, such as this one from Amazon, but if you want to make it even easier you could buy drawstring burlap sacks, similar to this bulk buy from Amazon.

My potting shed, albeit a little damp, is fairly sheltered, so I usually wouldn't need to give the tubers any further protection against frost. If, however, you wanted to make sure they were extra cosy, you could cover your crates of wrapped tubers with a layer of horticultural fleece, just like this from Amazon, and they'll benefit from an additional layer of insulation.

I wouldn't advise you to leave tubers outside once wrapped, but if you have no other option, or if you are worried about excess moisture in your shed or greenhouse, you could also cover them in a waterproof tarpaulin, (I like this heavy duty one from Amazon).

If you are an organised gardener (unlike me), you'll also need to make sure you label each tuber as you wrap it up. Popping a wooden label, just like these lovely ones from Amazon, in with each tuber or tying it onto the burlap parcel with twine, will help you to identify them correctly when you come to wake them up in the spring.

Essential kit for overwintering a garden

With their dazzling show that lasts well into the fall, dahlias are some of the best summer flowers for filling out borders. Growing them alongside all your other seasonal favorites, or even next to some veggies, can be tempting. However, not every type of plant will make a good neighbor.

While you don't need to be a super experienced gardener to grow dahlias successfully, there are a few things to consider to help them thrive. Deborah Stone of Stone Hollow Farmstead says, 'Dahlias are heavy feeders with delicate needs, especially when it comes to pests, airflow, and root competition. While many plants make wonderful companions, there are a few that can hinder their growth or invite trouble.'

Below, you'll find five types of plants to avoid growing next to your dahlias, and reasons why. If you're hoping to achieve your best dahlia display yet, be sure to keep these in mind.

1. Water- and drought-loving plants

When choosing plant companions, it's crucial to consider whether they like the same growing conditions. Some plants do best with plenty of water, for instance. It's no use putting these alongside those that prefer a drier environment – you'll only make maintenance tough.

When it comes to picking neighbors for dahlias, Peggy Anne Montgomery of Garden Media Group underlines this point. 'Water-loving plants like flag iris and marsh marigolds that thrive in soggy soils are poor companions, because dahlia tubers will rot in wet soil,' she says. 'Keep water-loving plants in rain gardens and wet areas.

'Drought-loving plants and desert natives are also not a good combination because dahlias need moist, well-drained soil,' she adds.

2. Certain types of veggies

According to Peggy Anne, plants in the cabbage family (such as broccoli and kale) should not be grown near dahlias. 'They can attract aphids and caterpillars, which can spread and harm dahlias and cause damage to flowers and leaves,' she says.

While it is possible to get rid of such pests, it's best to keep these leafy greens in a vegetable garden, safely away from your vulnerable ornamentals. Certain companion plants, such as marigolds, can help keep the pests away from your crop.

Potatoes are another veggie to keep away from your dahlias. Peggy Anne warns that they share similar disease susceptibilities, making them a risky combination. 'Potatoes can carry viruses like potato virus Y and potato spindle tuber viroid, which can spread to dahlias, causing them to become diseased,' she says.

Plant tomatoes, peppers, and eggplants away from dahlias, too. Deborah explains they are notorious for attracting spider mites, especially in warm climates. 'Since spider mites are one of the most damaging pests for dahlias, planting these crops nearby increases the risk of infestation.'

3. Large perennials and shrubs

One place you should never plant dahlias is somewhere with limited sunlight, as they need plenty of it to perform well. With this in mind, be sure to consider the mature height of potential companion plants.

Hydrangeas, large shrubs, and trees are poor companions as they can overgrow dahlias, says Peggy Anne. This can deprive them of sunlight, as well as water and nutrients.

'Dahlias have a shallow root system, and these larger plants will easily out-compete them. The same goes for large perennials like Joe Pye weed and tall rudbeckia,' she adds.

4. Zinnias

Like dahlias, zinnias make excellent cut flowers, however Deborah advises against planting them next to one another.

This is because zinnias are highly susceptible to powdery mildew – 'a fungal disease that spreads easily in warm, humid conditions. When planted near dahlias, they can reduce airflow and contribute to mildew problems that quickly affect both plants.'

Instead, she recommends growing zinnias in a separate cutting garden or in open, breezy locations where good air circulation can help keep mildew at bay.

5. Sunflowers

Sunflowers are another popular summer annual that should be planted away from dahlias.

Deborah explains that they are tall, nutrient-hungry plants that can compete aggressively with dahlias for water and minerals.

'Position sunflowers in their own sunny corner well away from dahlia beds, or ensure generous spacing and supplemental feeding to prevent nutrient competition,' she says. You can also grow sunflowers in pots – try the 'Tiger Eye Hybrid' variety from Burpee.

FAQs

What kills dahlia tubers?

Wet and cold conditions can cause dahlia tubers to rot, so be sure to choose the right planting spot for them and to overwinter them correctly. Many gardeners dig theirs up in the fall and keep them safely in storage before replanting in the spring.

How far should you plant dahlias from other plants?

Some plants do make good companions to dahlias, but don't plant them too close. Dahlias need space to grow well and get the nutrients they need. The exact spacing required will depend on the variety, as some dahlias grow much larger than others, but a minimum of 12 inches apart is generally recommended. Many dahlia varieties come with specific spacing instructions on the label.

'Keeping incompatible plants at a distance allows your dahlias to flourish – free from competition, pests, and disease,' says Deborah. 'A little thoughtful spacing can go a long way toward healthy, abundant blooms.'

There are other ways to get the most from these beauties, too. Our guides on pinching out and deadheading dahlias will come in useful.

A never-before-seen flower has been discovered at a dahlia farm in Enumclaw, WA. The so-called ‘Daffodahlia’ takes the form of a ball dahlia, with a distinctive trumpet-like shape at its center.

There are more than 40 species of dahlia globally, and thousands of dahlia varieties, but this brand new hybrid was discovered last month by flower grower Kelsey Hall, who runs Cattle & Cut Flowers with her husband, Kellen. Since then, the couple have been inundated with interest in this mysterious new dahlia from around the globe.

Speaking to H&G, Kelsey said she thought her eyes were playing tricks on her when she first saw the flower. 'I didn’t tell anyone about it for days because even looking at it a million times I couldn’t believe what I was seeing.' She says they will be testing several theories throughout the next growing season to try and find out how it happened, but in the meantime Kelsey tells us, 'the future for our farm will be hybridizing dahlias'.

After she first discovered it, Kelsey monitored the unusual flower over four weeks and found more Daffodahlia forms starting to bloom.

She says: 'We had 35 of this dahlia variety planted and 6 of the 35 plants started to push blooms in varying degrees of the Daffodahlia shape. In total, we saw around 40 of these blooms.'

After having the flowers tested at Washington State University, the Daffodahlia was found not to contain any known diseases or viruses. As a result, Kelsey has decided to embark on breeding her new discovery at the farm, and is working to find out if the flower mutation can be stabilized.

'We are letting the blooms stay on the plants and saving seeds to see if the plants can pass the genetics on next season through seed,' she explains in a recent Instagram post. 'We have leaf cuttings rooted in our grow room from plants currently creating the daffodil-like blooms. We will be growing dahlias in the grow room through the winter and would expect these to bloom sometime in late winter.'

What does the future hold for the Daffodahlia?

The Daffodahlia is not currently available for sale, and won’t be until the Halls can confirm the breed is genetically stable.

'We have tested in house and are monitoring the plants and will continue to do that as we pull the dahlia tuber clumps up,' she says. 'If the form returns and we can stabilize it, we will be putting the plants through more testing before we ever sell the stock to the public.'

Since the flower farm began in 2018, the team have never attempted any hybridizing of dahlias. But this discovery appears to be the catalyst for Kelsey to move into that space.

Kelsey tells H&G: 'We have sold dahlia seeds in the past and encouraged others to do hybridizing with our seed stock. We have wanted to move into selling dahlia tubers and seeds, cutting out some of the other things we do, so this was the push we needed. The future for our farm will be hybridizing dahlias.'

The Cattle & Cut Flowers team have made clear that should the form prove stable, it would not be available to purchase for a minimum of three to four years.

'We have no idea, nor does anyone, if the Daffodahlia will return next season,’ explains Kelsey. ‘This may have been a one time miracle of Mother Nature. We are doing what we can to try to get it to return by taking cuttings to grow through winter, saving seeds, and the tubers. If the form returns, we will take the steps to preserve it and grow it out to take to market. The reality is it wouldn’t be until 2028/29.’

There is, however, one way of getting a step closer to a Daffodahlias. The team is selling seeds from the tunnel where the flowers are growing, meaning there would be a small chance of cross pollination with these exquisite, unusual blooms.

Knowing how to grow dahlias successfully can take a bit of research and practice, but once you get some established plants, the huge, long-lasting flowers are just rewards. At this time of year, it's also useful to understand how to overwinter dahlias and whether you need to dig up tubers before the frosts and colder weather hit your area.

When I think of a flower I could never be without in my cutting patch, it would undoubtedly be dahlias. There are so many wonderful varieties of these magnificent flowers, some that form perfectly symmetrical pom pom spheres, and other, single petal varieties with glorious dark foliage.

There are a few handy tips to successful dahlia growing. These include deadheading spent flowers during the growing season to prolong flowering, as well as overwintering dahlias and storing the tubers properly to replant them the following spring. And, another very useful trick to ensure you get more blooms for your buck from these summer-flowering favorites is to pinch out their growing tips.

I’ve grown dahlias - both in beds and containers - for the best part of a decade, and ever since I learned the trick of pinching out I’ve been able to produce more flowers on every one of my plants. Here, I share with you my top tips for getting more out of these glorious garden blooms.

What is pinching out?

Pinching out is when we remove the growing tip from a plant in order to encourage side shoots to grow. By pinching out plants, the aim is to create larger, bushier plants with more flowers and crops on them, that will hopefully flower for even longer in the season.

It can feel very counterintuitive when you first have a go at pinching out, especially when a plant looks like it is growing away very happily. Why would you snip the top off it? I remember vividly having to force myself to do it initially, but once you see the results and understand how it benefits plant growth, you’ll be wholly converted.

When to pinch out dahlias plants

You need to wait until your dahlia plants have at least three pairs of leaves coming off the central stem before starting to pinch out the growing tips. This will have given your dahlia enough time to establish, and grow strong and heathy foundation foliage.

Depending on the variety of dahlia you are growing, this will usually be when the plant is 10 inches tall - possibly more.

As soon as you see three healthy sets of leaves you can pinch out the central growing tip. Any earlier and you will affect its future growth. However, each plant needs enough time in the growing season to recover and produce side shoots, so don't leave it too much later either.

How to pinch out dahlias

Always use clean and sharp pruning tools for the job to ensure you get a sharp cut, and don’t risk passing on any diseases to your plants.

You can simply use your fingers for the job if your plants are not too large, but I always prefer the clean cut you get from snips like these, from Amazon, and they are so easy to use.

Take a look at your plant and identify the central bud. This should be easy to see, as it will be growing at the top of the main stem. You can make sure you are looking at the central stem as all the other sets of leaves will be growing out from it.

Take your snips and carefully cut out the tip, just above a set of leaves. This will encourage the plant to divert its energy and for side shoots to sprout. For every set of leaves on the plant, you will get two more stems, which equates to up to four times more flowers from each dahlia tuber.

So now you can simply watch as your flowers multiply. The new, lateral stems should develop in as little as two days. The pinching out process does put the flowering time back by a week or so, but it also prolongs the season, as you will have so many more flowers on each plant blooming at different times.

FAQs

What happens if I don’t pinch out my dahlias?

If you don’t pinch out your dahlias they will still grow and bloom beautifully, but you will usually only get two or three flowers at the top of your plant. This is perfectly fine, but if you want more flowers on your plants, pinch out to encourage those side shoots.

Can pinching out damage dahlias?

Pinching out does not damage dahlias, or any other plants you use this technique on. The only dangers are pinching out too early, which could jeopardize the future health of the plant, and not cutting in the right place.

You can also pinch out a bit too late, when the growing tip has become much wider. As dahlia stems are hollow, this could cause damage if too much water or pests settle inside the stem.

Getting more flowers from your plants is a goal for all gardeners, and by using this simple, free technique you can really make the most of your dahlias. For more dahlia care and propagation tips, you can read our guides on how to harvest dahlias seed and how to plant dahlia tubers.

Dahlias are hugely-popular summer flowers that come in a wealth of bright colors and shapes. They have become increasingly fashionable again in recent years and, if you want to add these bold blooms to your backyard, they can be grown from seed.

Traditionally, many people grow dahlias from tubers that are commonly planted in late spring and lifted again in fall to protect them over winter - though dahlias can overwinter outdoors in warmer climates. 

Growing dahlias from tubers is a reliable and steady way to grow traditional types of dahlias, however, growing dahlias from seed can be a simple and fun way of adding to your collection, rewarding you with a variety of different dahlia blooms.

Why grow dahlias from seed?

Growing dahlias from seed can be a budget-friendly way to get a lot of bright blooms for your backyard ideas. The cheerful plants can be added to beds, borders, raised garden beds, or containers, to provide dazzling splashes of color come summer. 

We hear from expert flower growers about why and how you should add growing dahlias from seed to your spring to-do list.

Types of dahlias to grow from seed

There is a lot of mystery involved in growing dahlias from seed - and the excitement is part of why so many people do it. If you plant dahlia tubers every year, you know exactly what flowers will appear from that tuber. However, with dahlia seeds there is not the same level of consistency. 

Packets you see sold in garden centers and online will tend to be described as mixes, as there is no guarantee you can grow a specific type of dahlia through sowing seeds. The blooms that come from growing dahlias from seed are going to be a whole mix of colors.

Holly Heider Chapple, floral designer and owner of Hope Flower Farm, says ‘the unique and exciting possibilities the seedlings offer are very enticing’. She adds: ‘If you are growing from seed, you are excited about the possibilities, or you want dahlias and are not committed or need specific dahlias.’

The intrigue that comes with growing dahlias from seed is down to the fact that plants are unique - no two plants will be exactly the same when growing from seed. Meredith Bishop, sustainable flower grower and owner of Bloom and Bounty, hails the prospects and opportunities that can come with dahlias grown from seed. 

She claims: ‘Growing dahlias from seed is a fascinating way to create new varieties, and you can save the tubers from your favorites to plant out the following year’.

When and how to start dahlias from seed

Dahlia seeds are best started in a protected indoors environment around 6-8 weeks before your last frost - the timing of which will depend on your US hardiness zone. The seeds can be started in a heated greenhouse, in a heated propagator, or indoors on a warm and sunny windowsill. 

The reason for starting so early is that, as Meredith Bishop explains, ‘dahlia seeds can be slow to germinate, and somewhat sporadic in timing, so giving yourself plenty of time to grow a healthy stand of dahlia seedlings before planting out is best’. 

Seeds are best sown into a good-quality potting soil designed for seeds. These products are the best soils to start seeds in, and are better than using homemade compost, old garden soil, or reusing potting soil. Fill seed trays or small pots with potting soil and thinly sprinkle the dahlia seeds over the top, before covering again with a light layer of more soil or vermiculite. 

Dahlia seeds ideally want a temperature of 70°F or over, and lots of light. The experts at Swan Island Dahlias recommend that ‘they do not need any additional light, other than what Mother Nature gives us during the daylight hours’, so grow lights are not a prerequisite and a bright window can suffice. Keep the soil moist and check regularly for when to water - the soil wants to be damp but not waterlogged, and not allowed to dry out at all. 

Seedlings in trays will need pricking out and potting on when they are large enough to handle and have got their first set of true leaves. Gently separate the seedlings and pot them up into small pots filled with potting soil. Grow them at temperatures of at least 60°F and continue to give the young plants lots of light to prevent leggy seedlings, as well as keeping the soil moist as the dahlias grow.

When to plant out dahlias grown from seed

The seedlings can be transplanted out into the garden at least a month after being potted on, once the risk of frosts have passed and the soil temperature has risen.

Meredith Bishop says: ‘Because dahlias are somewhat cold-sensitive plants, it's best to wait until temperatures warm sufficiently before transplanting baby seedlings outdoors. Generally, this will be around 4-6 weeks after your last spring frost date.’

The small plants will need to be hardened off before you plant your dahlias, to get them acclimatized to their new outdoor growing space. Bring them outdoors during the day, and back in again at night, for at least a week to reduce the risk of them suffering from shock when being transplanted.

As with planting dahlias grown from tubers, the plants want a really sunny spot and to be in a fertile soil type that drains well. Plant dahlias grown from seed around 18 inches apart in the flower bed or cut flower garden, or you can grow dahlias in pots to provide pops of color around a small backyard space, patio, deck, or balcony.

The care and maintenance for them is then the same as any other dahlias. The plants need regular watering to keep them happy and feeding with a high potash fertilizer during summer can help to promote flowering. Pruning dahlias and deadheading dahlias will also help to keep dahlias blooming for longer.

If you live in a climate that has cold winters and frosts, then you have two options with your seed-grown dahlias. You can either simply grow the dahlias as an annual and let them succumb to the winter weather, or lift the plants to overwinter in a cool and frost-free place ready to plant out again come spring.

FAQs

Are dahlias hard to grow from seed?

Growing dahlias from seed is not a tricky task, however their germination can be erratic. For example, the experts at Swan Island Dahlias estimate that ‘the usual success rate in dahlia seeds is 50-75%’. If you can give them sufficient heat and light, hopefully any seedlings will develop within a few weeks from sowing. Then it is simply a case of protecting them from cold temperatures until the time comes to plant them out into the garden.

How long does it take to grow dahlias from seed?

It can take a while to grow dahlias from seed and it may be between 100 and 120 days from when you sow the seed to the first flowers appearing on your new dahlia plants. The exact length of time will depend on when and where you sowed the seed, along with the weather conditions after the seedlings were transplanted out into the garden.

Will dahlias bloom the first year from seed? 

Dahlias will produce flowers in their first year - from my personal experience I have got blooms in the summer from sowing dahlia seeds in spring. It may be a bit of a surprise to see what blooms you get, but if you give the plants lots of sun and water they will reward you with flowers. The blooms themselves are not going to be as large or strong as dahlias grown from tubers, but are still a delight and can be used as cut flowers in a display.

Do dahlia seeds turn into tubers?

Dahlia plants grown from seed will produce tubers as they grow. In their first year it will only be a few small tubers, but these can be lifted to overwinter the dahlias and planted again the next spring to grow again. The tubers will grow and bulk up each year they are planted and grown. 

However, there are no guarantees and an air of uncertainty may remain about what you will get in the second year. Holly Heider Chapple says: ‘The seedlings will produce tubers by the end of the growing season, but remember, what the tuber will produce is unknown.

‘I learned many years ago from Donald Dramstad, the acting president of the American Dahlia Society, that seedlings can not be trusted to produce consistently until they have maintained their color, form, and shape for three years.’

If you want to continue the cycle, why not consider harvesting dahlia seeds from your plants to sow come spring? There is no guarantee what blooms you will get from any seeds collected from your dahlias - whether the original plants were grown from seed or tubers - but it can be a novel trial and a simple way to get even more colorful blooms for your backyard.

Dahlias produce wonderful blooms in a plethora of colors and shapes in mid-summer and into fall. These popular plants are traditionally grown from tubers, but did you know you can also grow dahlias from seeds and even harvest dahlia seeds from your existing plants to grow new ones?

Harvesting dahlia seeds is simple, though there is no guarantee that the seeds you germinate will replicate the parent plant. If you want a specific type of dahlia, then taking cuttings or dividing tubers is the best way to go. As dahlias cross-pollinate easily, it will be a surprise what blooms come from harvested dahlia seeds.

If you are not fussy about what dahlias you get and are happy to experiment, then we get some expert advice for when to harvest dahlia seeds and store them correctly to ensure you have lots of saved seeds to sow come spring.

When to collect dahlia seeds

Dahlias will flower profusely whether you are growing them in flower beds, a cut flower garden, or you have your dahlias in pots. It is important to resist the urge to go out and deadhead all your dahlias throughout the blooming season. Rather than pruning every dahlia, leave some flower heads to develop seeds that you can collect. 

That time for collecting and saving seeds from dahlias comes in the fall. Jennifer Gulizia, an experienced flower grower from The Flowering Farmhouse, collects seeds from her dahlias in September and October towards the end of each growing season. Pollination is key to producing seed, and Jennifer has a trick when it comes to fading blooms that increase the chances of having dahlia seed to harvest.

She says: ‘Once the dahlia flower has started to die back, I help by gently pulling off some of the petals so that the stamen is more readily visible and accessible to the bees. 

‘Once the flowers have been pollinated, the dahlia flower heads will start to close up and form a seed pod. This usually takes about 4-6 weeks.’

When pollination has occurred a green seed pod will form inside the old blooms, which then turns brown when it is ready to be harvested. Swan Island Dahlias in Oregon recommends that it is ‘best to leave blooms on your plant for about a month prior to frost and then harvest the seed pods after frost, allowing them time to fully develop’.

How to collect dahlia seeds

The process of harvesting dahlia seeds is a simple one and you need only a pair of clean and sharp pruning shears or garden scissors and a brown paper bag to collect the dahlia seed heads in. Using a paper bag is a tried-and-tested method when it comes to collecting seeds. Paper bags are available on Amazon or in stores and are commonly used when collecting flower seeds, including when harvesting coneflower seeds among many others.

Identifying ripe and ready seed pods is important, making sure they are brown in color and dried up. Use your pruning shears or scissors to snip the seed heads from the plant and collect these into a brown paper bag. 

The seed heads will need to be dried and then gently opened to be able to collect and store the seeds inside. The seed heads can be left in the paper bag in a dry and cool room for two or three weeks, or spread out on a tray so they naturally dry in the open air. Then comes the time to harvest the dahlia seeds from inside the seed pod. The dahlia seeds themselves are small and flat, dark brown or black in color, and each seed pod may have up to 20 seeds inside it.

Miguel Palma, professional gardener and owner of JardinTienda, says: ‘These are the dahlia seeds you'll use for propagation. To separate them from any remaining plant material, gently rub the seeds between your fingers.’

You need to have a plate or container to hand to separate the seeds into. Having a vessel to catch the seeds ensures you do not lose any of your precious harvested seeds.

Storing harvested dahlia seeds

Whenever you are collecting seeds, it is important to ensure that they are completely dry before storing them away. Proper storage is important to ensure the viability of the seed. A failure to dry seeds properly before storing means they are likely to start going moldy in storage. 

Once the seeds are dry, Miguel Palma recommends: ‘Placing the dry seeds in an airtight container, such as a small envelope or a glass jar with a tight-fitting lid. To further protect the seeds, store the container in a cool, dry, and dark place, such as a refrigerator. You can add a packet of silica gel or a desiccant to absorb excess moisture.’

It is important to label and date the collected seeds for record-keeping purposes. Your harvested dahlia seeds can be sown in the following spring to germinate. The resulting dahlias are then planted out into a sunny spot in the garden once the risk of frosts has passed.

FAQs

Any time you are growing dahlias you want the best blooms possible. There are ways to keep dahlias blooming and that includes keeping your eyes peeled for dahlia pests and dahlia diseases – taking prompt action as required. With a bit of care and attention, you can easily have fantastic blooms for months.

Dahlias are impactful and glorious plants, with a varied and colorful selection of blooms to choose from. Any display of flowers can unfortunately be sorely impacted by a long list of pests that can ravage a plant.

The likes of aphids, thrips, spider mites, and slugs can all be problems to home dahlia growers. Some of these pests will be too small to see with the naked eye, but the devastation they cause can quickly become evident.

If you are growing dahlias then there are both natural preventative measures you can utilize to deter pests, and actions to take once any infestation has been spotted. A good set of eyes, and taking a quick course of action, can ensure your dahlia display for the summer is not ruined.

What bugs eat dahlias?

There is such a huge variety of dahlias to grow and admire in your flower beds or pick as part of a cut flower garden. However, all types of dahlias can fall foul of pests that want to munch on the leaves, petals, or flower buds.

Zahid Adnan, experienced gardener and founder of The Plant Bible, claims that regular inspection of your dahlias is ‘paramount’ as pests can ‘quickly wreak havoc’ on your precious plants.

‘If left unchecked, pests can weaken the overall health of the dahlia, potentially leading to stunted growth or even death of the plant,’ he says.

‘By closely monitoring your dahlias, you can identify pest problems early and take timely action to prevent infestations from becoming uncontrollable. Early detection also allows for a more targeted and effective treatment plan.’

We take a look at some of the most common dahlia pests and the damage they can do to your plants: 

Thrips - If you get thrips on dahlias they cause damage to leaves and petals, causing puncture wounds on the foliage and turning leaves yellow

Aphids - Aphids are tiny insects that congregate in huge numbers on plants. Aphids on dahlias are commonly seen on the underside of leaves, or sometimes on stems. They cause foliage to distort or curl and can attract mold and other insects to the honeydew that they secrete

Spider mites - It may be difficult to see spider mites on dahlias as they are tiny, you will need a magnifying glass to spot them. Leaves will discolor, turning a yellow tinge and with a red webbing on the backs of affected foliage. Spider mites start from the bottom up, with the oldest leaves getting hit first

Earwigs - The main issue from earwigs on dahlias is that they cause a lot of aesthetic damage, shredding blooms and chomping on leaves. Edges will be nibbled and holes pincered through petals and foliage. 

Slugs and snails - The distinctive slimy trails along with nibbled leaves and stems are classic signs of snails or slugs eating dahlias. These voracious and common garden pests can do huge damage to young and fresh growth not long after you have planted dahlias in the yard

Capsid bugs - Dahlias are particularly susceptible to these in late spring and early summer. John Negus, gardening expert, explains how these small pale-green insects suck sap from developing shoot tips and cause real harm. He adds: ‘The saliva of these insects is toxic to plant cells and as the young leaves at the shoot tip grow and expand, the damaged areas become distorted and tear into small holes, which then become ragged.’

Measures to prevent dahlia pests

Planting your dahlias in the best position and in good-quality soil can help to ensure your plants are healthy and strong. Flourishing plants will be more resistant to pests, and also dahlia diseases. Therefore, it makes it important to put your dahlias in a sunny location with fertile soil, ideally enriched with compost or well-rotted manure, that drains well. If you are growing dahlias in pots then location and the soil will also be key areas to get right, as well as making sure any planter has holes in the bottom for drainage. 

As well as location, proper maintenance plays a part in combating potential pest problems. Correct watering, careful and proper feeding, and removing any debris from around the dahlias will ensure plants are not stressed, and provide nowhere for the pests to hide. When you are pruning dahlias or deadheading dahlias then keep a close eye for any damaged sections too, and remove them from the plant.

Companion planting can be utilized to repel pests that might otherwise look to attack your dahlias. There are many pest-repellent plants that can be used to discourage certain pests, with the likes of marigolds, chrysanthemums, lavender and calendula great options to deter many insects. 

You can buy lavender seeds and plants from Burpee

How do you treat dahlia pests?

The largest pests, including slugs and caterpillars, can be hand picked from the plants, while smaller infestations can be squashed by hand also. Regular inspection is recommended and it may mean heading out in the hours of darkness with a torch, as slugs and snails are night-time feeders. 

Another simple way to get rid of aphids, or get rid of spider mites too, is to dislodge them from the plants with a blast of water from a garden hose. There are also organic sprays, or homemade bug sprays, which you can use to control the pests.

John Ehrling from Garden Savvy says targeted chemical insecticides should only be used ‘as a last resort', so recommends a few more natural treatment options which are available.

He says: ‘Insecticidal soap or horticultural oil can be used to treat soft-bodied pests like aphids, spider mites, and thrips, suffocating them while being less harmful to beneficial insects. 

‘Neem oil, an organic option, can help control a wide range of pests by disrupting their feeding and growth. Biological control can be introduced by releasing beneficial insects like ladybugs and praying mantises into the garden to keep pest populations in check.’

There is also the possibility of using a natural bacteria in the form of Bacillus thuringiensis to combat caterpillars and their larvae. Any such products are very specific to the insects they are targeting and should be used carefully. One example of such a product is the Caterpillar and Webworm Control, available at Amazon.

A specific trick for getting rid of earwigs is suggested by Tony O’Neill, an experienced gardener and author from Simplify Gardening, who says: ‘Earwigs can be trapped using damp, rolled-up newspaper or straw placed near the base of the plant at night. They will hide in there, allowing you to dispose of them in the morning.’

FAQs

Keeping an eye out for pests, and also diseases, should be seen as an essential part of how to keep dahlias blooming. Not only are they capable of ruining the aesthetics of blooms but are also potentially problematic for buds, causing them to grow in a distorted manner or not open at all. Stopping them from attacking, or dealing with any outbreaks quickly, will ensure plants put on a fantastic display of colorful dahlia blooms for longer.

Their array of wonderful colors and flower shapes results in a spectacular display in the late summer garden, but to get the most from these plants, you’ll want to be confident about how to keep dahlias blooming.

Dahlias put on a fantastic show, and it’s also possible to grow dahlias of many varieties in containers on the patio to enjoy their color and sculptural forms here, too. 

Plant dahlia tubers and you’ll discover their needs aren’t onerous, but it is the case that they require a little care for maximum flower power. We asked the experts to share the secrets of keeping dahlias blooming to create color and interest from late July to the first frosts.

Essential knowhow to keep dahlias blooming

Understanding when to plant dahlias is crucial to enjoying a fabulous array of blooms, but if you want the very best from your plants, there are a handful of tasks you should carry out. This is how gardening professionals ensure impactful and long lasting dahlia displays.

1. Deadhead dahlias

If you want to keep them blooming for the longest possible time, deadheading dahlias is a must-do job. ‘When deadheading dahlias, it is important to remove the old flower head and stem down to the next highest bud as this helps to strengthen the remaining stem,’ advises Steve Bradley, an expert for Amateur Gardening magazine.

Take care that it’s the spent flowers you’re removing and not buds. ‘There are always exceptions in gardening but, as a general rule, the flower buds are usually quite rounded as they develop,’ says Steve. ‘Once the petals have fallen, what remains of the flower head becomes quite pointed and is often a slightly paler color.’

2. Stake flowers

Staking dahlias helps to preserve the display of blooms, but staking is also important because it supports the whole plant, points out Steve Bradley. 

‘Fully open flowers can become heavy (especially after rain) and drag the whole plant down onto the soil if the plant has not been staked,’ he explains. ‘Insert stout canes or stakes (often three to four) around the plant when it is 12 to 18 inches in height, making sure to avoid damaging the tubers.’

3. Feed plants

Feed dahlias to keep them flowering, although, as Susan Brandt, co-founder of Blooming Secrets, explains, there is some dispute. ‘Some people say dahlias are heavy feeders and others say they don’t need anything,’ she points out. Her advice? ‘To get your dahlias off to a good start make sure the soil is fertile with lots of organic matter. You can fertilize every three to four weeks from sprouting in midsummer until early fall.

‘When fertilizing use one with a high percentage of phosphorus, which will promote blooming. Make sure it is not high in nitrogen as this will create great foliage, but few blooms. A recommended fertilizer ratio is 10-30-20. If you plan to dig up your tubers make sure you stop fertilizing at the end of August. If you keep fertilizing your tubers, you are encouraging growth when you should be preparing your tubers for dormancy.’

4. Water according to weather

For great dahlia flowers, it’s important to get watering right for the conditions. ‘Watering quantity and frequency is very much weather dependent,’ explains Steve Bradley. ‘A dahlia plant 40 inches tall and 40 inches across needs around 4½ gallons of water per week in dry weather.’

5. Watch out for pests

If you want to keep dahlias blooming, it’s important to be vigilant regarding pests and dahlia diseases. ‘One common pest that can affect dahlias is the aphid,’ says Susan Brandt. ‘These small insects feed on the sap of the plants, causing stunted growth and distorted leaves. To control aphids, you can use insecticidal soaps or neem oil, which are safe and effective methods.

‘Another pest is slugs. This pest often is a problem in the early season when the foliage is tender and easier to eat. Using an irrigation system that soaks the soil and keeps the leaves dry is a good way to prevent them from appearing.

 ‘In terms of diseases, one notable issue for dahlias is powdery mildew. I have personally experienced this disease with my dahlias. This fungal infection appears as a white powdery coating on the leaves and stems of the plant, leading to reduced vigor and blooming. To combat powdery mildew, ensure proper air circulation around your dahlias by spacing them adequately and removing any infected foliage.

‘Another disease that can hinder dahlia blooming is crown rot, which affects the roots and crown area of the plant. Overwatering or poorly drained soil can contribute to this condition. If you notice wilting or darkening of stems near the soil line, it may indicate crown rot. To prevent this disease, make sure your dahlias are planted in well-draining soil and avoid overwatering.’

FAQs

Dahlias can produce one of the most eye-catching of sights in the summer garden. However, because they are tender perennials, if you live in zone 7 and below, if you want fabulous blooms next year, it’s important to overwinter dahlias. Lift the tubers and store them after the first frosts ready for replanting in the spring.

From midsummer onward, dahlias often take the limelight in a garden – and deservedly so. Their vibrant colors and fabulous forms are nothing short of wondrous, and they make excellent cut flowers, too. But if you want the very best from your plants, you'll need to get the know-how on pruning them.

There are a few benefits to cutting dahlias back. To start, it's a good idea to deadhead them throughout the season to encourage more flowers and keep their appearance tidy. But, there are other ways to prune these summer favorites – from pinching out and thinning to getting them ready for winter. This guide covers all three, so you can enjoy your most spectacular dahlias yet.

How to pinch out dahlias

One of the best ways to encourage better-performing dahlias is to remove the tips when they are growing, in spring. This is known as 'pinching out', and a similar process can be applied to sweet peas and zinnias. 

Gardening expert John Negus suggests using a knife to do this, such as the Fiskars Garden Hori Knife from Amazon, rather than pruners. It's less likely to damage the stems. As always, ensure your tool is sharp and clean – not doing so is a common pruning mistake and can spread diseases and pests from plant to plant.

Simply remove the growing points when the plants are around 12in high, John instructs. Cut just above a healthy set of leaves. 'They will respond by producing side shoots, which will make plants bushy and trigger a wealth of blooms,' he says.

Top tip: If you want your dahlia to produce bigger blooms for bringing indoors, remove any smaller buds that develop behind the main, central ones, advises the Royal Horticultural Society (RHS). This process is called 'disbudding'.

How to thin out dahlias

Some types of dahlias can also benefit from a springtime thinning. This can improve the health and performance of the plants if they're prone to becoming congested. It can also provide a better balance of foliage and flowers.

Simply remove the more spindly and overcrowded shoots, says the RHS. You can do this by hand. Leave around seven to ten strong stems on the plant – or less if you're growing varieties with particularly large blooms.

New shoots that appear around the base of the plant can be used for propagation. Take 2-3in cuttings from them, says John. 'Make a horizontal cut below the lowest leaf joint and remove leaves from the lower half of the cutting.  Finally, insert the dahlia cuttings to half their length into a proprietary seed and cutting mix and root them in a heated propagator or somewhere similar.'

If you spot any dead or diseased stems on your dahlia, remove these too, says Diana Cox of TheGardeningTalk.com.

Pruning dahlias at the end of the season

When the first frosts arrive, dahlia foliage will turn black. At this point, you can prune the plants right back, ready for winterizing. Shorten the stems to within 8in of the base, says John. Then, lift the plant with a spade.

You can then store the tubers somewhere dry and frost-free, before re-planting them in the spring.

Alternatively, after cutting them back, you can apply a layer of mulch around the base of the plants to protect them from the cold, says Diana. However, this is only suitable for warmer climates – if in doubt, lift them for storage.

Cutting back dahlias, once you know how, is a simple task that's definitely worthwhile. But don't forget there are other essential ways to look after these plants for big and beautiful blooms – including regularly feeding them. Frequently watering them is important, too, especially during dry spells and if you're growing them in pots.

Dahlias come in a wealth of shapes, sizes, and colors, they are hugely-popular plants that provide a real pop of drama to any backyard bed or border. They are also susceptible to many fungal problems, viruses, and bacterial diseases.

When you plan how to grow dahlias you want to know that you are giving your plants the best chance against potential dahlia diseases. Simple things like correct spacing and proper watering can all make a difference and help dahlias to thrive.

Unfortunately there is no treatment for some dahlia diseases and it can be the end of the road for the plants. This is where it is important to stack the odds in your favor by making the right decisions and not falling foul of all-too-common errors that can increase the likelihood of diseases hitting your dahlias.

How to prevent diseases in dahlias

Many dahlia diseases can be combated by maintaining good plant health and using proper cultural practices. This good practice can start from right when you plant dahlia tubers as part of any backyard ideas, through all the essential maintenance tasks such as watering, feeding, and deadheading dahlias.

Amelia Haslehurt, a seasoned horticulturist and creator of Locally Grown Gardens, has cared for a large number of dahlias and highlights some key points that dahlia growers should consider to help mitigate the chances of any potential diseases affecting plants.

She recommends: ‘To reduce the risk of dahlia diseases, ensure proper spacing between plants, water in the morning so leaves dry out during the day, and practise regular crop rotation. 

‘Always remove and destroy diseased plant material, and keep the garden clean and free from debris to reduce the chance of disease starting.’

Observation is an important element too, as regular inspections of dahlias can mean spotting any problems quicker. This allows for prompt action that can help prevent the spread of dahlia diseases and also reduce the severity of any infections. 

Common dahlia diseases

When you are looking to buy any types of dahlias, always ensure to get certified virus-free dahlia tubers from reputable nurseries or suppliers, and do your research as there are varieties of dahlias that are resistant against certain diseases. 

You can reliably shop the range of dahlia tubers at Nature Hills 

We take a look at some of the most common dahlia diseases to reveal the signs to look out for and what can be done to deal with the problems.

1. Gall

Crown gall is a bacterial disease of dahlias and it causes swellings, the aforementioned galls, on the stems and roots. They can first appear as small swellings that break up on stems, but the galls will turn hard and permanent on the tubers. One problem with crown galls is that the presence can often be unnoticed until you lift the tubers to overwinter the dahlias. 

Crown gall, and also leaf gall which is another bacterial disease that hits dahlias and causes abnormal clustered shoots to grow, gets into the plants through wounds. These can be natural, or can be man-made when planting or pruning. It is important to use clean and sterile tools when cutting dahlias to prevent the spread of infection. 

Unfortunately, there is no effective treatment for either crown gall or leaf gall and any infected plants need to be removed and destroyed. Never use infected plant material to make compost.

John Negus, plant expert for Homes & Gardens, advises that best practice if your dahlias have contracted gall is to ‘bin or burn the diseased dahlias, and set new ones where you have not grown them before’.

2. Mosaic virus

The American Dahlia Society claims that over a dozen viruses are known to infect dahlias and the mosaic virus itself is ‘highly prevalent’. The signs include distorted, mottled, or streaky foliage, small flowers, and stunted growth. Yellow streaks in the foliage are caused by chlorophyll loss, while the distortions will include rolled or cupped leaves. 

The virus can be spread from an infected dahlia to other plants, often by aphids but also by humans when they use dirty tools. Sanitized garden tools can help prevent the spread and you can use the likes of soapy water, diatomaceous earth, or companion planting to help get rid of aphids. 

Always use food-grade diatomaceous earth, which is available from Amazon.

No dahlias are available that are resistant to mosaic virus and once a plant is infected it cannot be cured. Remove and destroy affected plants and never propagate from infected tubers. 

3. Powdery mildew

Powdery mildew is a common fungal issue that can hit a huge variety of plants, both edible and ornamental. It will show as white powdery spots on leaves and the stems and is often at its worst during hot and humid periods. 

Good watering practices can prevent the spread. It is always best to water plants at the base and sprinkling water from above is a common garden watering mistake. Doing this can spread the spores that cause powdery mildew. Also water plants in the morning so the leaves dry during the day, as wet leaves left overnight are at risk of fungal problems. 

You can get fungicides intended to use against powdery mildew, such as the Garden Safe Fungicide Spray available at Amazon.

John Negus advises that there are ‘several ways’ of avoiding powdery mildew. He says: ‘Don’t let plants dry out at the roots and grow them so there is plenty of air between them – space them out and reduce shelter from taller plants around them. Also, avoid water sitting on the leaves for too long. 

‘If you spot infections early, remove the leaves to take away the source of infection, though don’t take too many as this may weaken the plant. You can take cuttings in spring so long as the new growth is not emerging through soil/compost that’s covered with the remains of this year’s foliage.’

4. Smut

Dahlia smut is a fungal issue that causes irregular spots to appear on leaves, which turn into dark lesions. It is rife in cool and wet conditions and can be spread by rainfall or overhead irrigation. A serious infection of smut can distort plant growth and result in reduced overall vigor of the plant. 

Keep a close eye on your plants and remove any affected parts right away and try to refrain from watering plants from overhead. Planting at the correct spacing to allow for good air circulation and better drying of moisture on leaves can help to curb the threat of smut and other fungal diseases. The disease can also overwinter in soil attached to the tubers when they are stored for winter. 

5. Wilt

Verticillium wilt and fusarium wilt are soil-borne fungal diseases that can affect dahlias at any stage of their lifespan. The results can be devastating as the plant dries up and wilts, often starting on one side of the dahlia. This can quickly spread, seemingly out of nowhere as they suddenly collapse, and can eventually kill the plant. 

There is no chemical option for wilts and control can be tricky as the pathogens that cause it are in the soil. Crop rotation can help to prevent the build up of diseases spread in the soil, as is knowing your soil when planning a garden and making sure you do not plant dahlias in soil where wilt has been an issue. 

Whether you are growing dahlias in pots or planning a cut flower garden that includes magnificent dahlia blooms, always do your research. Pick the right types, plant them at the right spacing, and learn how best to look after them. Not only will you get a bounty of great flowers, but the risks of diseases will have lessened as a result. Bad practices can attract diseases or leave plants stressed, which puts them at more risk of succumbing to dahlia pests and diseases.

A key consideration when choosing the best types of dahlias is knowing they will last as long as possible. You need to make sure your favorites are up to the task of producing long-flowering displays. 

There are over 40 species and thousands of dahlia varieties, plus countless hybrids. But if you are looking to grow dahlias specifically for their staying power, choose pompon dahlias, small and miniature ball breeds, and compact cactus varieties. Not only are these perfectly suited to gardens of any size, they are the best options for making the flowering season last longer. 

Extending the season has a lot to do with making things trickier for bees. Single-flowered dahlias, with a few rows of petals around a yellow eye, are easy for bees – when they land, the pollen is right there, so they collect it and pollinate the flower at the same time. At that point, flowers start to fade. By contrast, dahlia flowers packed with petals are harder for the bees to pollinate. Small and miniature ball and pompon varieties (and cactus types with tube-like shapes) are a struggle to pollinate so they last longer, although the bees do get there in the end!

16 types of dahlias to try

As well as needing dahlia displays that last for months, you should look for dahlias that fit in with other flowers and bloom well into the fall. Consider varieties that are not overdominant and blend well with other plants in mixed flower bed ideas and border arrangements. 

Below are some of the best dahlias in a selection of pompon styles, plus small and miniature ball and cactus varieties. They complement other flowers in mixed arrangements and are particularly long flowering. 

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1. Dahlia ‘Cornel’  

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 4ft
• Good for: Large patio pots

‘Cornel’ is one of the most long-lasting pompon dahlias. It has rich, velvety, cherry red flowers that are 4in across. These are slightly darker in the center and tightly packed with petals. This is one of the dahlia varieties that is especially productive, reliable and weather resistant.

If you want to grow dahlias in pots, this one works well in large patio tubs, as well as planted in mixed borders. It is also great for cutting. Partner with bronze-leaved castor oil plants or variegated miscanthus.

2. Dahlia ‘Franz Kafka’ 

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 32in 
• Good for: Cottage gardens

This pompon dahlia forms flower heads like slightly flattened spheres 2-3in across. The shell-like lilac pink petals are tightly packed, beautifully arranged and reward close inspection.

‘Franz Kafka’ is one of the best dahlias for mixed borders and patio pots. It is also amongst the best cottage garden plants you can grow, and capable of lovely cut flowers. Partners well with pastel roses and silver foliage.

3. Dahlia ‘Kasasagi’

• Type: Long-lasting pompon dahlia
• Hardiness: USDA Z8
• Height: 32in
• Good for: Sunflower themes

If you’re after a dahlia for mixed borders and cutting gardens, ‘Kasasagi’ (available at Etsy) is an ideal pompon variety. It sparkles in a sunny border and partners well with crocosmias and kniphofias. If you grow sunflowers, this is also a smart dahlia to grow alongside small-flowered helianthus.

Uniquely bicoloured 2in flowers have bright yellow centers. Each small floret matures to bright yellow with rich orange backs and edges, all held on orange-tinted stems.

4. Dahlia ‘Moor Place’

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 40in
• Good for: Exhibitions, cutting gardens

Dahlia ‘Moor Place’ is an exceptionally productive variety. It features small 2in flowers in a sumptuous wine-purple shade. This is slightly darker in the center, with the petals rolling back right under the flower to make an elegant symmetrical shape.

This is one of the most striking dahlia varieties and partners well with pale blue larkspur and foamy white aruncus. Remember to deadhead dahlias promptly so fading flowers don’t detract from its rich display.

5. Dahlia ‘Nuland’s Josephine’

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 3ft
• Good for: Mixed borders

For gardeners with an eye on more adventurous garden color schemes, ‘Nuland’s Josephine’ is a bold and unique pompon dahlia. Its tones have been likened to rhubarb and custard. It is one of the best dahlias for mixed borders, subtle dahlia combinations and exhibitions. 

Flowers are three inches in diameter. Each shell-shaped floret is a rich rose wine shade on the outside and peachy gold on the inside. It partners well with other pinks and peachy shades, or planted in front of a silver-leaved shrub.

6. Dahlia ‘Rhonda Suzanne’

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 4ft
• Good for: Cutting gardens

Another of the most dazzling dahlia varieties for perennial sunflowers in lemony shades, ‘Rhonda Suzanne’ AGM also works well alongside other purple plants and those with silver foliage. It looks stunning in mixed borders and cutting gardens, and especially pretty in small posies.  

This dahlia has neat little 2in green-eyed flowers, with florets in a tight symmetrical pattern. They are a slightly variable blend of rich purple and white. Expect variations in the richness of the purple, depending on the weather and rainfall.

7. Dahlia ‘Small World’

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 5ft
• Good for: Grasses, meadow styles

‘Small World’ AGM (available at Walmart) is exceptionally productive over a long period. For those interested in white garden ideas, this is one of the best dahlias you can grow. It looks especially lovely partnered with green-leaved grasses and purple Michaelmas daisies.

Its brilliant white ball-shaped flowers are lemony in the centers. The stems are long and strong and the flowers are weatherproof. Deadhead promptly as the browning petals can detract from the pale flowers.

8. Dahlia ‘Willo’s Borealis’ 

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 4ft 
• Good for: Asters, pompon themes

The neat pompons of ‘Willo’s Borealis’ are filled with rich lavender florets. These are dark in the center at first, developing a yellow eye as flowers mature. Pinch once to prompt a flurry of long-stemmed blooms.

This is a great dahlia variety for themed displays of different pompon breeds, cutting gardens and exhibitions. Partner with other pompon varieties in harmonious shades, such as ‘Franz Kafka’ and ‘Willo’s Violet’, plus yellow perennial asters.

9. Dahlia ‘Willo’s Violet’

• Type: Long-lasting pompon dahlias
• Hardiness: USDA Z8
• Height: 4ft
• Good for: Pink and purple themes

‘Willo’s Violet’ is another one of the best perennials you can grow for exhibitions, as well as for themed displays of pompon dahlias. It is also another one of the best types of dahlias you can grow for cutting. 

It is similar to ‘Willo’s Borealis’, but a noticeably darker and richer shade with a few flashes of white at its heart. Partners well with other pompons in harmonious shades, such as ‘Franz Kafka’ and yellow perennial asters.

10. Dahlia ‘Josudi Andromeda’

• Type: Long-lasting miniature cactus dahlias
• Hardiness: USDA Z8
• Height: 5ft 
• Good for: Mixed borders

Perfect for mixed borders and cutting garden flowers, ‘Josudi Andromeda’ is ideal if you fancy growing miniature cactus breeds. This unusually strong-growing variety is best pinched out twice to promote prolific flowering.

The startling blushed pink 2in flowers tend to richer tones in the center and are reminiscent of sea anemones. Its stems are long, but strong enough to support the flowers. This dahlia makes an appealing contrast with other pompons and ball dahlias.

11. Dahlia ‘Weston Pirate’

• Type: Long-lasting miniature cactus dahlias
• Hardiness: USDA Z8
• Height: 5ft
• Good for: Red floral themes 

If you want to plant a cottage garden border, ‘Weston Pirate’ AGM is amongst the most dramatic miniature cactus breeds. These dahlia varieties have rich, fiery red flowers like exploding fireworks. The 3-4in flowers look especially good against the dark green foliage.

Also ideal for mixed borders, dahlia borders and shows, they partner well with pompon or ball dahlias in similar shades – the contrast in shapes is very effective. Cut for the house or deadhead regularly.

12. Dahlia ‘Weston Spanish Dancer’

• Type: Long-lasting miniature cactus dahlias
• Hardiness: USDA Z8 
• Height: 3ft 
• Good for: Tropical themes

Another of the best dahlias for two-toned displays, ‘Weston Spanish Dancer’ works equally well as a specimen flower and as part of a broader mixed or dahlia border. Partners beautifully with plants that have bronze foliage or intense purple blooms. Just make sure it is well supported. 

This startling variety has eye-catching yellow and scarlet flowers, with heads 3-4in in diameter. The lower half of each tubular floret is bright yellow, while a few red streaks mark the transition to pointed red tips.

13. Dahlia ‘Blyton Softer Gleam’

• Type: Small ball dahlias
• Hardiness: USDA Z8
• Height: 5ft 
• Good for: Chrysanthemum pairings 

With its soft, intriguing palette, ‘Blyton Softer Gleam’ is one of the ball dahlia varieties that seems most confused about what color it is, falling somewhere between peach and gold. The effect is stunning, though.  

Coral orange as flowers open, it matures with yellow tones. The 4in flowers are packed with neat florets and fit well into a fall-infused color theme. Pairs well with hardy chrysanthemums, perennial asters and other dahlias in fall shades. Best pinched out at 12in in height.

14. Dahlia ‘Clearview Daniel’

• Type: Small ball dahlias
• Hardiness: USDA Z8
• Height: 5ft
• Good for: bronze and yellow themes 

‘Clearview Daniel’ is a classically rounded, 4in ball-shaped flower in a pure lemon yellow. This is a striking American variety which is making its mark on both sides of the Atlantic. It is an unusually strong growing variety with stout stems, so it’s great in exposed situations. 

It is one of the best dahlias for a small backyard, creating long-lasting displays in mixed and dahlia borders, as well as shows. Pairs especially well with dahlias that have bronze leaves, such as the Bishop Series.

15. Dahlia ‘Hamari Rose’

• Type: Miniature ball dahlias
• Hardiness: USDA Z8
• Height: 4-5ft 
• Good for: Rose pairings 

Creating the perfect complement to long-season roses and bronze-leaved cannas, ‘Hamari Rose’ is one of the best dahlias for long-lasting mini ball blooms. It is perfect if you are planning a cut flower garden, and also looks great in mixed borders and dahlia borders.

Elegant, neatly arranged, 3-4in flowers have florets in rose pink, fading towards white at the edges. At the center, florets are a richer shade with a metallic or coppery look. Cut for the house, or deadhead regularly.

16. Dahlia ‘Jomanda’ 

• Type: Miniature ball dahlias 
• Hardiness: USDA Z8
• Height: 5ft 
• Good for: Salvia pairings
  

Rounding off our selection of the best dahlias for long-lasting floral displays is this terracotta treat. ‘Jomanda’ is a mini ball variety that produces slightly rusty colored orange flowers (3-4in). They fit well into fall tones and are held on dark stems that make an attractive contrast.

For those who like to grow salvias, this dahlia is an ideal pairing for the deeper blue varieties. It also partners well with perennial asters and aconitums. Lovely in mixed borders, dahlia borders and cutting gardens.

Protecting dahlias from the first frosts of the fall is a sure way of extending the flowering season. In fact, it is often the early morning sun that does the damage, as foliage with frost on it warms up too quickly. 

When you plant dahlias, choose a site that is protected from the early sun (and easterly winds) as this is a big help to ensure these stunning blooms can flower for as long as possible. 

Q: I love dahlias for their vibrant colors and intricate forms. This year, I would like to plant them in pots to brighten up my outdoor seating space. Are there any container-growing tips I need to know to keep them looking their best?

A: Dahlias are a great choice for a sunny container garden – and there's such a wide variety to choose from. Growing them this way is similar to how you'd grow them in the ground – however, there are a few things to bear in mind for the best display possible.

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How and when to plant dahlias in pots

Planting dahlia tubers in pots should be done in mid-to-late spring, when risks of frosts have passed. You can plant them a little earlier if starting them in a frost-free greenhouse – when temperatures rise, harden the plants off for a week or so before moving them outdoors permanently.

'Set one to a 12in container,' instructs John Negus, a gardening expert. He advises covering the base with drainage material – crocks or stones – and filling it with loam-based potting compost. The tops of the tubers should poke through the soil's surface.

If you're growing a tall variety of dahlia, add a stake to the compost to help support it as it grows. Then, lightly water the compost, and wait for green shoots to appear. Once they do, continue to water lightly – not too much at first as this can cause the tubers to rot. 

When the plants are about 12in high, remove the growing tips. This will reward you with bushier plants and more blooms.

If you're buying pot-grown plants from a garden center in summer, plant these straightaway, at the same level that they were planted originally.

How to care for dahlias in pots

When strong new shoots form, John says to start liquid-feeding the plants on a weekly basis with a high-potash tomato fertilizer – such as Espoma Organic Tomato-Tone from Amazon. 'Continue until late summer.'

Once they have established in their pot, dahlias are thirsty plants. Ensure you give them plenty to drink, especially during periods of drought. However, don't overdo it – a common container gardening mistake – as waterlogged soil can damage the tubers. Putting the pots on pot feet, such as these UFelice pot risers from Amazon, will help any excess water to drain away.

Dahlias make beautiful cut flowers. But, if you're leaving some blooms to enjoy in your garden, deadhead them once they've gone over to encourage more. Cut just above the top set of leaves on each stem. 

Winterizing dahlias in pots

In colder regions, you will need to take steps to winterize your dahlias, as they are not hardy plants.

In the fall, you can cut the stems back and lift the tubers to dry off before storing, says John. 'Remove as much compost as possible and then either hang them upside down or sit them somewhere warmish for a few days to dry out.' They can then be stored in trays of sand that are kept somewhere frost-free.

'Alternatively, if you have the space, you could put the pots somewhere frost-free, and leave the tubers undisturbed, letting the stems die back naturally,' he says. 'Keep them somewhere warmish and light in the first instance to give the compost a chance to dry a bit, but not enough to encourage the stems into growth. Once the stems have died back, the pots can be put somewhere dark and cool but it must be above freezing. If there is a chance of them getting frosted, wrap them in newspaper, fleece, or a blanket to keep them a bit warmer.' You can move the pots back outside when the weather warms.

FAQs

Without a doubt, dahlias are one of the best summer bulbs for a spectacular show, suiting cottage-garden schemes and modern backyards alike. And, by planting them in pots, you can enjoy them in any-sized space – even a compact balcony. 

Dahlias are the undeniable superstars of the summer flower bed, and knowing how to deadhead them is crucial for keeping these showy and flamboyant blooms flowering for longer.

There is such a wide variety of dahlias to enjoy, coming in a vast array of colors, varying flower sizes and shapes, multi-colored blooms or dark foliage cultivars. Growers across the world continue to introduce new variations and color shades to keep up with the trends – in fact, the range of sizes and colors is practically unmatched in the world of flowers. And the good news is that with the right care and attention, dahlias can keep flowering from summer into winter.

Once you learn how to grow dahlias and see the first blooms unfurl you'll soon become obsessed with them. So, to keep dahlias blooming for longer, discover exactly when and how to deadhead dahlias with tips from an expert dahlia grower.

What we mean by deadheading dahlias

Deadheading dahlias involves only removing the spent flower heads and buds. This does not harm the plant. Instead, by removing the dying blooms, you encourage the plant to put its energy into root and flower development.

'Unless you’re leaving seedpods to mature on the plants for breeding purposes or collecting seeds, be sure to remove any spent blooms so that the plants continue to put energy into flower production rather than making seeds,' explains expert flower grower Erin Benzakein, author of Floret's Farm's Discovering Dahlias, available on Amazon. 'This practice is an important ritual in the cutting garden if you want a steady stream of beautiful blooms for the longest amount of time.'

How to deadhead dahlias

As with deadheading or pruning any flowers, make sure you have the correct equipment to hand so as to avoid damaging the plants. 'You will need a sharp knife or pruning shears, such as these soft grip Fiskars pruners from Amazon, to deadhead dahlias,' explains Rachel Bull, Head of Gardens at H&G, and cut flower grower.

Once your dahlias begin to bloom, it's good practice to inspect the flowers at least once a week to check if there are any dead or dying flowers. Remove flowers as they begin to wilt and any that have completely wilted and are beginning to form seed pods.

You'll soon find when learning how to deadhead dahlias that it's easy to identify spent blooms, where the petals are wilting and starting to fall off. However, if you miss this stage, it isn't always as easy to identify which buds you should deadhead and which are on their way to producing blooms.

'It can be tricky to tell spent buds from new ones sometimes. The key is in the bud shape. If it’s pointed and a bit squishy it has gone over; if it is round and perky, it is a new bud,' explains Rachel.

After you’ve identified which flowers are wilting or buds you need to deadhead, then using a pruner, cut the flower stem as its intersection to a leaf. This will promote more blooms and avoid the sight of flowerless stems sticking out all over the place.

The ideal time to deadhead dahlias

The exact time of year for deadheading dahlias will depend on when they start blooming, which will differ depending on the hardiness zone where you live.

Once you see flower blooms have wilted and buds are spent, you know it's time to begin deadheading. It's a good idea to begin deadheaded dahlias every week to keep them blooming, although in high season this can increase to every few days.

Where to deadhead dahlias if a stem has more than one bloom

The tricky part of deadheading dahlias is when there are multiple heads on one stem. If one of the flowers has gone over you have two choices: you can either take off the dead flower by cutting back to the bud joint, leaving the other buds to bloom, or, you can make the decision to cut further back down the stem at the next set of leaves.

'If the flower stems are short, I tend to cut the dahlia back further down the stem to encourage longer new shoots for cutting to create a summer flower display. Having one of the short flowers cut off from a three-headed flower stem might not look great in a vase,' says Rachel. 'But if you are growing dahlias for color in the border for garden color schemes, then this may not be an issue.'

FAQs

Are there other ways I keep my dahlias blooming?

The best way to keep your dahlias blooming is to deadhead spent blooms regularly, and also cutting flowers for floral displays around the house, which will encourage your plants to produce more blooms.

'Like any plants, dahlias are prone to bacterial, viral, and fungal diseases when stressed,' explains expert flower grower Erin Benzakein, so make sure you keep your plants happy and healthy, by planting in the right spot, allowing lots of airflow and caring for and watering them correctly. Where you do encounter pests or diseases, 'I advise using organic methods as much as possible. Growing naturally takes more effort and attention, but pays off in the quality of the flowers,' Erin adds.

Dahlias make wonderful cut-and-come-again blooms if you're planning a cut flower garden because they flower for months on end. Deadheading and picking these invaluable late summer flowers regularly encourages them to keep producing more flowers right up to the first frosts.

Once you know how to grow dahlias you can fill your garden with bursts of color from late summer into fall. Boasting a huge array of colorful flowers in all sorts of sculptural forms, and in bloom from July right through to the first fall frosts, these showy plants are a brilliant option for late summer flower bed ideas. 

There really is a dahlia to suit all gardens and tastes. Choose from bright and bold vibrant tones to subtle pastel shades, and from the daintiest lilliput and single flower varieties, to multiple petalled pompons and dinner-plate sized forms. They create a mesmerising display and can look particularly effective planted en masse or as part of a mixed border, but there are many varieties that will happily grow in containers on a patio, too.

Dahlias are also a brilliant flower for cutting, with stems lasting up to a week in a vase and the more you cut them the more they grow. Plus, they are marvellous multipliers: from a single tuber you could get up to ten 'baby plants' by the end of the growing season. 

Tips for growing dahlias

You can buy dormant dahlia tubers to plant in spring, or pre-order them earlier from a specialist nursery for delivery in spring. You may even be able to take some from a kind friend who has divided their clump of tubers. 

Dormant dahlias will come delivered in the form of tubers – clusters of brown, potato-like roots joined together on a dried stem, and are among the best summer bulbs to plant. All tubers will be different sizes. Ensure that each tuber has some stem and at least one of the buds or ‘eyes’. 

Knowing when to plant dahlias is a crucial part of learning how to grow dahlias. Dahlias are frost tender so can only be planted out once the danger of frosts has passed, allowing about eight weeks to the start of flowering. 

If you have the space, you are best starting to grow dahlias under glass. 'You can pot them up in March or early April, in a generous pot (at least 2 litres) filled with multi-purpose potting compost. Place them in a light, frost-free place and keep the compost moist. They will have formed bushy plants by the time the frosts have ended and will be in flower by the beginning of July,' advises plantswoman Sarah Raven.

Where to plant dahlias

Dahlias will grow best in a sunny spot, protected from strong winds, in rich, moist, well drained loamy soil but not wet, waterlogged soils.

'Dahlias thrive in warm, sunny weather. Plant them in a spot that gets at least six hours of direct sunlight each day. Otherwise your plants will get leggy reaching for the light, and they won't bloom as abundantly as possible,' advises flower farmer and dahlia expert Erin Benzaken, author of Discovering Dahlias, available on Amazon.

Plus where there is sunshine, there are also pollinators. 'Open centered dahlias are becoming very popular because of the easy accessibility of their pollen for bees and other insects. Not all of these make much of a statement in the garden, often having small flowers, but there are some that do,’ says June Nash of The National Dahlia Society.

Prepare the soil well for the hungry plants. Improve it by adding in organic matter, such as home-made compost or well-rotted manure, over the area where you’re planning to grow dahlias.

How to grow dahlias

The best way to grow dahlias is to start them off in pots as they are frost tender. By planting the tubers into pots the plants can be kept under cover in a greenhouse or sun room and protected from the cold weather. There are also smaller, dwarf varieties that are ideal for growing in pots as part of your container gardening ideas.

Here's our step by step guide on how to grow dahlias in pots from tubers:

1. Pot up the tubers into five-litre pots, approx 8in in diameter, filling them up to their necks in potting compost and ensuring that the stem/crown is pointing up.  
2. Water the pots and leave them in a sunny spot, undercover in the greenhouse or a sun room. Growth rates will vary but you should see shoots start to appear within five weeks.
3. Dahlias should not be planted out until the risk of frost has passed, but as they grow they can be brought outside during the day to help them acclimatise and to give them maximum sunshine. They must be brought in at night.
4. When your dahlia plants are around 12 inches tall the growing shoots can be pinched out to encourage a bushier plant and more blooms.
5. Dahlias are hungry plants that like being kept moist; digging in plenty of well-rotted manure or organic matter to the soil before planting them in your flower bed will keep them well fed and help the ground retain moisture.
6. Once the risk of frost has passed, your dahlia plants can be planted out into their flowering position. Spacing will vary depending on variety but generally dahlia plants will need to be spaced around 20 inches apart.
7. Dahlias can grow up to 5ft tall so will need support, particularly if you are growing the giant dinner-plate varieties. Once planted, add in bamboo stakes which can be used to tie the plant into as it grows, alternatively you can buy metal support rings that can be placed around the plant.

Dahlia tubers can also be planted directly into the ground once the risk of frost has passed. To do this dig a hole about 12 inches deep, add in some compost or manure and wet with a watering can of water. Position the dahlia tubers about 4 to 6 inches deep with the crowns pointing up.

Some dahlias can also be grown from seed which can be done undercover in spring. To grow dahlias from seed, sow the seeds onto the surface of moist compost in a seed tray and cover with vermiculite. Keep in a sunny spot in a greenhouse or on a windowsill. Once seedlings are big enough to handle pot them on into individual pots. Plant out once the risk of frost has passed. You can even harvest dahlia seeds from existing plants to grow new ones – though there is no guarantee that the new plants will replicate the parent dahlias.

Care tips

• Pinch: As the dahlias grow, pinch out the growing tips to promote bushy growth.
• Feed, feed, feed: Once a fortnight, between July and September, feed dahlia plants with a liquid balanced feed to boost flowering, such as a good tomato feed.
• Water: You will need to water your dahlias once a week in dry weather by giving them a good soaking down to the roots.
• Protect: Protect from dahlia pests such as slugs and snails by adding nematodes to the soil, or add barriers, such as rough or sharply textured types of mulches.

Choosing the right dahlia for your yard

A member of the asteraceae family, there are around 36 species of dahlias, with thousands of various cultivars and hybrids. Skilled breeders across the world have produced a wide range of dahlia sizes and colors practically unmatched in the world of flowers. Sizes range from the smallest lilliput to dinner plate-sized blooms and there is every color except for that most elusive color for breeders – blue.

Dahlias can be described as: 

• Decorative
• Cactus
• Anemone
• Waterlily
• Pompon
• Balls
• Collarette
• Dwarf
• Peony
• Orchid

Select varieties for your weather conditions and by the shape, size and color.

Open–centred single and semi-double varieties that produce an array of simple flowers are the best choice for pollinators and flowers that attract bees as they can see where to land and feed on the nectar, and look charming mingling with asters and other daisy shaped flowers.

Decorative and cacti dahlias are brilliant varieties if you're planning a cut flower garden, as their blooms are a good size for displaying in a vase. While giant varieties such as Cafe au Lait, look show-stopping in a border, their large, dinner-plate blooms are often too large for cutting. 

There are some lovely more diminutive varieties that are perfect plants for pots, such as dwarf colarettes, lilliputs and the low-growing Topmix series.

FAQs

For truly beautiful late summer blooms that last right into fall, the main thing to remember is to deadhead dahlias. Pick for the house regularly, or snip off old flowers as they fade to prevent making seeds. The more flowers start to develop seeds, the fewer new buds will be formed.

They bloom from mid-summer to late fall, but you might be asking when to plant dahlias to enjoy their extravagant display. 

Growing dahlias extends the season with big, bold flowers that fill the backyard with color. Most are tall, adding height at the back of the border, and the single-flowered cultivars provide nectar for bees and butterflies. On top of that, dahlias have a cut-and-come-again habit, so they supply beautiful, fresh flowers for the house. 

Our guide has the details on when to plant dahlia to get the most from these colorful, exotic flowers. 

When to plant dahlias

Hailing from Central America, dahlias shouldn’t be planted outside until the weather warms. If you have stored or bought tubers the answer to when to plant dahlia tubers is to pot them up under cover (for example, in a greenhouse) in March or April. Rooted dahlia cuttings are also best started off under cover in mid to late spring. And potted dahlias should go in the ground after risk of frost has passed, which is May or June in most regions. 

Dahlias are available in such a vast range of colors and shapes that you can select the ones that best suit your style of garden. For instance, the cactus and ball varieties bring retro glamour; the single and anemone forms fit into jungle-style flower bed ideas; and the huge dinner-plate dahlias are a must-have for a cutting garden. 

‘I like to intersperse dahlias among other plants,’ says Oregon-based landscape architect and garden designer Bethany Rydmark. ‘For example, dahlias work well in modern meadows, as accents in a mixed border, or as infill in a parterre.’

When to plant dahlia tubers indoors

Dahlia tubers that you have stored over winter or bought can be potted up under cover (for example, in a greenhouse) in March or April, and then planted outside in May or June. 

‘Planting tubers will often give you earlier flowers,’ say Dave and Sue Hall at specialist dahlia nursery Halls of Heddon, near Newcastle upon Tyne, UK, ‘because more often than not they will produce multiple shoots which will not need pinching out.’ 

It is best to harden off the young plants to acclimatize them to outdoor conditions before planting. For example, by placing them in a cold frame or by sitting them outdoors during the day for a week covered with fleece, then gradually remove the fleece.

When to plant dahlia tubers outdoors

What about when to plant dahlia tubers outdoors? ‘Dahlia tubers can be safely planted out between April and May,’ say Dave and Sue Hall. ‘The warmer the climate, the earlier you can plant. So the further south you live in the UK, the earlier you can plant.’ 

In most parts of the UK and the northern US, it is safe to plant dahlia tubers direct outside from mid to late April. 

Usually, the tubers will set about growing their roots during late spring and begin sending up new shoots in early summer. However, sometimes they may shoot early in warm spring weather. Don’t worry because this won’t damage the plant in the long run. 

‘Growth that emerges too early may be nipped back by spring frosts,’ say Dave and Sue. ‘The plants will recover and it should result in bushier plants earlier on, as they will have had a natural pinch.’ 

When to plant rooted dahlia cuttings

Mini plants, known as ‘rooted cuttings’, are readily available from dahlia suppliers in mid to late spring. They are often more reliable than tubers in establishing robust plants faster and can produce a better flower color. 

If possible, plant them up under cover (for example, in a greenhouse) during spring. ‘Dahlia rooted cuttings can be planted directly outside, but they will certainly benefit from being potted up and grown on for at least a few weeks before planting out,’ say Dave and Sue Hall. ‘In the south of the UK, planting out can be done from early to mid May. In the north and Scotland, you would not normally plant out until June. We would not advise planting out before the date of the last expected frost in your area.’ 

Harden off the young plants before planting out, in order to prepare them for the weather outside. For example, by placing them in a cold frame or by sitting them outdoors during the day for a week covered with fleece, then gradually remove the fleece. 

When to plant potted dahlias

In late spring and early summer, ready-grown dahlias in pots can be bought from nurseries. As for when to plant dahlia like these? They can be put directly into sunny borders once all risk of frost has passed. 

‘Only buy fresh, strongly growing plants that have not become pot bound,’ advise Dave and Sue Hall. ‘Being pot bound will put a check on their growth and they will be slower to get away.’ 

To check if a plant is pot bound, peer underneath to see what the roots look like. If they are old and in a dense knot under the plastic container or – if you are able to slide the plant out of its container – should they be growing around and around the compost, avoid purchase.

When to sow dahlia seed

Dahlias are usually grown from tubers, which is far easier and quicker. However, if you like a challenge, they can also be raised from seed. Sow the seed under cover (for example, in a greenhouse or on a bright windowsill) in early spring. Once they are large enough, harden off the young plants and then plant into borders in June. 

When should I start my dahlia tubers?

Start dahlia tubers in March or April by potting them up under cover; plant them outside in May or June. If you don’t have space to start them in a greenhouse or indoors, dormant tubers can be planted directly outdoors between April and May.

How late can you plant dahlia tubers?

You can plant dahlia tubers as late as May or June in most regions. When it comes to their blooming season, they should carry on up until frost.  

It’s vital to know how to plant dahlia tubers correctly if you want to guarantee a spectacular show of flowers.

When learning how to grow dahlias, you will discover there are varieties available in a huge range of colors and forms – from flawless geometric shapes to flouncy romantic blooms.

There are dahlia types suitable for both pots and borders, and they are also one of the most popular options for growing cut flowers, making them an essential addition to your garden ideas.

‘Few plants can rival the flowering power of a dahlia, and the best part is that growing them is easier than you may think,’ says Gail Pabst from the National Garden Bureau.

Simply plant dahlia tubers at the right time, and give them the right conditions, and come summer you’ll be rewarded with a glorious display that will last into the fall.

Before the frost sets in and the ground freezes over, make sure you know how to overwinter dahlias, and they’ll return year after year, growing more abundant each time.

Learn how to divide plants and you can propagate more of your favorite dahlia varieties.

How to plant dahlia tubers – expert guide

‘Dahlias are relatively easy to grow and need only a few essentials: good soil, adequate water, and lots of sun,’ says Erin Benzakein, author of Discovering Dahlias.

Before deciding how to plant dahlia tubers, you must first make sure they are in good condition, and not showing damage or signs of rot. Tubers also need to have all the necessary elements.

‘In order to grow and reproduce, a dahlia tuber must have three key components: the main body, which holds the nutrients and energy needed to produce next year’s plant; an eye or eyes, which will eventually swell and sprout, becoming the stalks of the new plant; and a sturdy, unbroken neck that connects the two other parts. Without any one of these, your tuber won’t grow,’ says Benzakein.

Dahlia tubers are somewhat fragile, so handle them with care. If you need to store your tubers before planting, then keep them somewhere dark, cool and dry.

When to plant dahlias

‘You can plant dahlia tubers directly into the ground in the spring when the ground is warm and there is little chance of frost,’ says Pabst. ‘One good guideline is to plant dahlias at the same time as you would a tomato.’

In many locations, this will be April to May. However, those in warmer climes may start the process a little earlier. If you are experiencing a lot of rain, then it’s best to wait until this has passed.

‘If you want blooms as early as possible, you can start dahlia tubers indoors in good light about a month before outdoor planting time,’ adds Pabst. ‘By starting early you could have a small plant ready to transplant in the spring.’ Alternatively, you can keep your dahlias in their pots and move them onto a sunny patio when the weather warms for a gorgeous container display.

However, don’t rush to plant your dahlia tubers outside. ‘While it may be tempting to start growing dahlias as soon as possible, ideally wait until the ground has warmed up and all frost hazards have passed,’ says Nikitia, owner of Mit City Farm. 

‘The ground temperature should be at least 60°F (15°C). Check the USDA Plant Hardiness Zone map to find out the last average frost date for your growing zone.’

How to plant dahlia tubers in the ground

Before planting dahlia tubers in the ground, it’s important to create the right conditions for them to thrive.

‘Dahlias perform best when grown in full sun and in fertile, well-drained soil,’ says Tammy Sons, horticulturist and owner of Tennessee Nurseries.

To increase your chances of success, enrich the soil with compost or organic matter, and mix it in before planting.

‘Use an all-purpose granular fertilizer for the biggest blooms and larger plants,’ adds Sons.

When planting dahlia tubers, it’s important to plant them with the ‘eye’ facing upwards. ‘The eye is the point on the shoulder, or crown, of the tuber from which the plant grows,’ says Pabst.

‘When planting dahlia tubers in the ground, the tubers should be 3-4 inches below the surface. Depending on the type of dahlia you have, it is often recommended to plant them 15 inches apart.’ 

However, larger dahlias may need to be spaced as far apart as 30 inches, so do check the ultimate size of your chosen variety.

Before covering your dahlia tubers with soil, it’s wise to add a stake or other plant support at this stage, to avoid later damaging the tubers. Many dahlias grow to 4-5 foot, or even taller, and their stems can easily be broken in the wind.

Backfill the planting hole with soil, and firm it in, before giving the soil a good watering. Unless the soil dries out, don’t water again until the green shoots appear, or the tubers could rot.

The dahlias should begin to sprout within a few weeks. Once they have grown around 8-12 inches tall and developed three pairs of leaves, pinch out the growing tips to encourage branching. This will ensure a bushier plant with more flowers.

To do this, simply remove 3-4 inches from just above a set of leaves, using sharp, clean pruners.

Do you soak dahlia tubers before planting?

It is not necessary to soak dahlia tubers before planting. However, some gardeners choose to soak them to rehydrate them after storage, and to speed up the growing process.

‘Soaking your dahlia tubers before starting them in pots will stimulate them to develop more quickly, which means they'll be ready to flower sooner,’ says Nikitia. ‘Soak tubers in a bucket of lukewarm water for an hour before planting to properly rehydrate them.

However, after this initial soaking and watering in after planting, she warns of being over-zealous with the hose. ‘Allow the soil to almost dry up before watering again while the plant is forming roots. The tubers will not dry out but may decay if the soil is kept too damp before the roots and top growth get a strong start.’

How deep should I plant dahlia tubers?

When planted in the ground, dahlia tubers should be at a depth of around 3-4 inches below the surface. 

When planting dahlias in pots, cover them with 1-2 inches of potting mix.

Learning how to overwinter dahlias is important, to guarantee that they return the following year. Dahlias tend to continue to flower right up until the mercury drops and the first frosts arrive, and so at this point, it is time to start the process of protecting your dahlias for winter.

Just like when learning how to grow dahlias, figuring out how to overwinter dahlias can seem quite daunting. Should you dig them up or leave them in the ground? How should you store the tubers? Will they regrow next year? All these questions are very important and the answers depend on both your local area and personal preferences.

There are lots of different methods available for overwintering dahlias, which means there will be a little bit of trial and error as you figure out the best way in your specific part of the world. It might be worth trying several different approaches to see which works best for you and your winter garden ideas.

How to overwinter dahlias: a step-by-step guide

Planning a winter garden does involve preparing more tender plants for dormancy during cold weather. The key thing to remember when learning how to overwinter dahlias is that the tubers should not be left to totally dry out, as you would with bulbs.

'Dahlias require a cool climate, ample air circulation, and being placed in a dark area if they are not being stored in soil media,' says Tammy Sons, owner of Tennessee Online Plant Nursery.

• The first frost marks the start of the overwintering period for dahlias. Wait until a frost has turned the foliage black, then cut the plant down to about 6 inches. Then lift the tubers and use your hands to get rid of the soil.
• Having lifted your tubers, the next step is to remove any rotten or dead matter. 'The tuberous roots should feel firm to the touch and not squishy when pressed,' says H&G gardens content editor Thom Rutter. 'If they don't feel firm or if they look rotten, then remove the rotten material with a clean knife until only healthy tuber remains.' Dispose of any unhealthy material on your compost heap.
• Some of the tuberous roots may have become detached from the main body – this is okay. The loose tubers can either be disposed of or you can store them with the rest of the dahlia to see if they might make a viable plant the following summer.
• Dead tubers appear withered and wrinkled. These also need removing and can go on the compost heap.
• Do not clean the tubers under a tap. Instead, turn the tubers upside down in a crate and leave to dry for a couple of weeks.
• Next, label your tubers, recommends Megan Foster, category manager of bulbs & perennials at American Meadows. 'As you build your collection of varieties, you will want to remember which is which come planting time in the spring. Use a marker or tie on a label with old twist ties.'
• Once the tubers have dried out sufficiently, it is time to store them for the winter. There are several methods for storing dahlias. The best method for how to overwinter dahlias primarily depends on where you a storing them. If you are storing them in a slightly moist environment opt for paper bags, such as these from Amazon, or cardboard boxes as these will absorb the moisture from the air. If you are storing them in somewhere that is drier, then a plastic box or bin bag is a better option as these can be occasionally spritzed with water.
• Unlike bulbs they also need to be insulated to keep them warm and prevent them from drying out. You can either cover them in loose, dry compost, sand, vermiculite, such as this from Amazon, or straw, or you can wrap each tuber in newspaper.
• Place your tubers in a dry and cool place – unheated greenhouses, sheds, porches or the cellar are all great options.
• 'Check on your tubers throughout winter looking for signs of rot or severe dehydration,' says Thom. 'If you spot signs of rot, cut away the compromised material until you are back to the healthy tuberous material. It is also worth moving your dahlias to a drier location to prevent further rot from taking hold.'
• Dehydrated tubers are the other challenge when learning how to overwinter dahlias. It is quite easy to tell if your dahlias are dehydrated as they will look shrivelled. If this is the case, occasionally spritz the dahlias with water to help them absorb more moisture.

When to leave dahlias in the ground

If you live in an area that experiences milder winters and you have very free-draining soil then you can leave your dahlia tubers in the ground. However, this is only suggested for hardiness zones 7 to 10.

If you are leaving your tubers in the ground, then there are some steps you must follow to protect them during the cooler months.

Once your dahlia plant has succumbed to the frost, leave it for about two weeks to let the sugars go back into the tuber, then cut the stem back to around 6 inches tall. Dispose of the foliage on your compost heap. After this, cover with a mound of deep mulch, such as this pine bark mulch from Amazon, to insulate the tubers throughout the winter months.

Overwintering dahlias using Saran Wrap

Overwintering dahlias in Saran Wrap, available from Walmart, is a fairly new method, however, it has received a great response. In fact, it is now the go-to method for the American Dahlia Society, having moved away from vermiculite and plastic bags.

Start by lifting your dahlias, as you would for any other method, and clear them of soil. Whether you treat your dahlias with an anti-fungal treatment to ward off rot is a personal choice, and should you not wish to, you can simply skip this step. However, it will offer greater protection for your dahlias over the colder months.

'Add a very small amount (around a tablespoon) of powdered sulfur to 3 cups of dry vermiculite in a gallon size Zip Lock bag and mix thoroughly,' suggests the experts at The American Dahlias Society. Then add your tuber and shake lightly so that your dahlia tuber is coated - 'a very, very light coating should be best.'

Having done this, set your dahlias aside in a crate to dry overnight before wrapping. 'Tear off a sheet of plastic wrap about 20 inches long and lay it flat on a level surface. Place a tuber on one end and roll the plastic wrap over one complete turn. Lay another along side and roll again. Be certain that no tuber is touching another; plastic wrap must separate all tubers.' Once you've wrapped your dahlias, fasten with masking tape and label with the dahlias's name before storing in a dark and dry place at around 40°F for winter.

FAQs

Should I split my dahlia tubers before overwintering?

Whether you split your dahlia all comes down to a matter of confidence and knowledge about how to overwinter dahlias. 'If you’re not sure where the eyes are, don’t break apart your tuber clump in the fall before storage. The tuberous fingers of the dahlia are winter sugar and moisture survival supplies for the eyes which are the source of new growth for next spring. If you disconnect the two accidentally, you’ll be disappointed with lack of growth,' advises Megan Foster, category manager bulbs & perennials at American Meadows.

However, if you are certain where the eyes are and that they are still connected to plenty of tuberous fingers, then you can separate the two before overwintering. To do this use a clean knife to cut away the eye and tuber. Then overwinter in the same way you would a non-separated dahlia.

Can you leave dahlias in pots over winter?

Although dahlias aren't candidates for the best winter plants for pots and borders, yes, you can leave dahlias in pots over winter. But, it is vital that they are sufficiently protected from the cold weather, either by bringing the pots indoors or by adding a layer of mulch and wrapping them in fleece.

When should I cut back dahlias?

Cut back dahlias in late fall – October and November is ideal. Leave the stems to go black from the first frost for approximately a two weeks to allow the sugars to go back down the stems to feed the tuber. Then cut the stems off just below ground level.

You should to do this whichever way you are overwintering your dahlia tubers, as it will increase their likelihood of survival, and the extra energy it provides will help them to restart growing in the following spring.

There can be a lot of facets to overwintering a garden, but if you prioritize tender bulbs and perennials, and take a few simple steps to protect plants from frost, your yard should be back to its full potential come the spring.

Created by floral designer Brigitte Girling, using flowers from her own garden, the starting point for this summer flower arrangement was the seasonal return of dahlias and plume poppies to her flower beds. 

‘Their warm apricot and peachy tones combined with the thundercloud colors of the ‘Amazing Grey’ poppy is a lovely combination,’ Girling says. ‘A walk through the garden unearthed the hint of both shades in a new addition to the garden party this year – coreopsis ‘Starlight’ – which simply sealed the deal.’

You will need:

Materials

Chicken wire, a small bowl, pot tape – try your local florist or hobby store.

Flower ingredients

Perennials: medium-headed dahlias ‘Cornel Brons’, ‘Sylvia’ and ‘Linda’s Baby’ ‘Nicholas’; garden roses ‘Lark Ascending’ and ‘Just Joey’; Achillea ‘Apricot Delight’; Macleaya cordata, plume poppy; Coreopsis ‘Starlight’; Gaura ‘Whirling Butterflies’

Hardy annuals: Papaver rhoeas ‘Amazing Grey’; Calendula ‘Touch of Red Buff’; Eschscholzia californica, 'Thai Silk' Series, 'Apricot Chiffon’ and ‘Pink Champagne’

Half Hardy Annuals: Cosmos bipinnatus ‘Purity’ and ‘Apricot Lemonade’

Brigitte Girling grows the flowers for her displays in her own chemical-free wildlife-friendly garden. For inspiration for your own plot, take a look at our country garden ideas.

1. Prepare your vessel

Scrunch some chicken wire loosely inside a bowl (a cereal bowl is ideal) and secure with pot tape. This will be the scaffolding that holds your stems. 

Add clean water to the top of your bowl.

2. Add your plume poppies

Create an outline shape using the plume poppy. 

Insert stands into the chicken wire around the outside of the bowl. The stems will feel a little loose at first but don’t worry; as more stems go in, they knit together and stabilise the design.

3. Insert the roses and dahlias

Add in the heavier roses and dahlias, trimming off thorns and unwanted leaves first. 

Group similar flowers together rather than scatter. The idea is to try to recreate a garden within your bowl. 

To grow your own flowers for a display like this, we have a guide to how to grow dahlias.

4. Create different heights in the display

Ensure all the flower heads are at different heights and different angles – not facing forward like a choir. Remember, the back of a flower can be just as beautiful as the front.

5. Finish with the most delicate blooms

The final flowers to go in are the airy dancers that float across the top. These are usually the most delicate so easily damaged if they go in too soon. 

In this arrangement, it's the annual poppies that are most delicate. See below for our tips to keep them fresher for longer.

Florist's tip: how to keep poppies looking perky

Annual poppies are fleeting; their vase life no more than three or four days. Furthermore, they can literally ‘flop’ very quickly once picked. Here, Brigitte Girling shares her knack for preventing poppies from drooping.

This boiling water treatment has the double benefit of sealing the stem ends and removing any air bubbles within the stem which cause the droop.

Brigitte Girling is the founder of Moss & Stone, where she offers 'undone floral designs' and workshops.

It's nearly time to awaken your dahlia tubers from their winter hibernation and get ready to kickstart them into action, advises Monty Don.

No garden would be complete without these fabulous flowers, and mid March, says the BBC Gardeners' World presenter, is when you should be checking over dahlia tubers ready for planting.

He shared his advice on how to check and plant dahlia tubers on a Gardeners' World video last March, so now is the perfect time to remind ourselves of his top tips.

March is the time to check on the condition of dahlia tubers that you dug up and stored away last winter in a dry, frost-free shed or greenhouse.

To inspect each tuber: 'first get rid of all the loose compost around it and check each dahlia is in good nick,' Monty Don explained. 

The respected gardening broadcaster advised to look for the following to check if the dahlia tuber is good:

• A nice plump dahlia tuber;
• Check the tuber is firm;
• If the dahlia tubers are too shriveled up they are too dry;
• If they are rotten they are probably too wet;
• Check for slug damage on the dahlia tuber;
• A little bit of mould on a tuber is no problem;
• Cut out bad or damaged tubers

Once you have checked the condition of the dahlia tubers and cut out any bad bits, you can plant them in pots, advised the gardening guru. For growing dahlias successfully, he has these tips.

'Use a plastic pot at this stage that is just big enough for them to grow. We want them to start to develop a root system,' the presenter advised.

Use a good quality, fresh compost as 'dahlias are greedy plants,' he added.

Water the potted dahlias, put them somewhere sheltered and warm to trigger the growth, such as in a cold frame, greenhouse or conservatory, and keep them moist by watering once a week. 

'Do not let them dry out. You'll very quickly see new shoots,' encouraged Monty.

Keep an eye on the mercury levels outside, however, as if another cold snap sweeps in, you may need to cover them with protective fleece.

The dahlias that have been potted under cover will be ready to plant out in the garden in about mid May, when the top growth is about a foot high.

'Dahlias are something that I'm going to be growing here at Longmeadow with a vengeance, because I love them,' added Monty.

Bright and bold dahlias are having a renaissance. These botanical favourites are filling Instagram feeds and the fact they’re back in fashion means there’s more variety than ever to choose from.

There’s no bigger fan of growing dahlias than florist and plantswoman Sarah Raven. Every year the gardens of her Sussex home Perch Hill are filled with masses of these brilliantly colored blooms.

Eminently attractive to bees, dahlias have dark foliage that is an excellent backdrop to other shrubs and flowers both in the border and in bouquets.

‘Dahlias are getting bigger and blowsier year on year,’ says Sarah, ‘with colours soft and romantic to go with it. And in perfect contrast, the dark port-wine reds are always popular, stopping any combination from becoming sickly-sweet.’ 

Dahlias will keep flowering as long as you keep picking them, so there’s no better excuse to fill your house with either single stems or big bunches as the mood takes you.

Sarah Raven's favorite dahlias

'I couldn’t be more proud of this collection,' says Sarah. 'Chosen from vast trial fields to bring home to Perch Hill, to grow, trial and evaluate, these varieties have out-performed all others.

'Not just in terms of beauty, but in vase life and general ease of growth and productivity. I truly love all eight.'

1. Mango Madness Dahlia Collection

'Sweet, but not too sweet, with a good waft of smoke and crimson richness to stop this fruity-colored collection from ever becoming cloying.'

2. Café au Lait Dahlia Collection

'Morphs from ivory to peach, coffee to cream. A popular choice at the moment, and can often be seen in summer bridal bouquets. The soft, creamy blooms can reach 25cm across – they look equally spectacular in the border and the vase. A true crowd pleaser.'

3. Parisien Chic Dahlia Collection

'A beautifully well-turned out bunch of dahlias, in crisp, clean colors, like a posse of catwalk beauties, a little distant and cool, but undeniably alluring. You will see these bursting into bloom from the beginning of July.'

4. Dahlia ‘Floorinoor’

'A bizarre and hugely pretty dahlia in all its stages, from bud to fully open flowers. Rings of flattened petalsencircle a denser central group of shorter, tubular petals.'

5. Dahlia ‘Preference’

'I first spotted this in a Dutch friend’s garden five years ago, but we could not get enough tubers until this year. Very pointy petals give a spiky appearance to this cactus variety.'

6. Dahlia ‘Cornel’

'True Venetian velvet pompoms, a dahlia cut flower and border classic, which has been around for years,' says Sarah. 'You will get months of flowering, five to be exact, out of these bright red pompoms that are ideal for vases.'

7. Dahlia ‘Omega’

'Part of the bumper Ascot hat brigade, Omega is head-turningly beautiful growing in the garden and picked for a bowl or vase.'

8. Dahlia ‘Thomas A. Edison’

'Dahlia ‘Thomas A. Edison’ is a true show-stopping dahlia and one of my long-standing favourites. Mix with other dahlias, or plant with veg.'

Sarah Raven's tips for caring for dahlias

Dahlias, which grow fresh from tubers every year, aren’t very good at pushing up through herbaceous plants, so the easiest way to grow them is to give them their own bit of space. There are also some that are perfect for growing in pots.

1. Stake medium-to-tall dahlias using bamboo canes placed in a circle around the plant, and wrap with twine.

2. Water during dry spells and feed with a high potassium fertiliser, such as tomato or comfrey, every week or so.

3. Deadhead regularly for best results.