5 climbing annual plants all gardeners should grow – to get astonishing flowers for the cost of a packet of seeds

If you're looking for the best fast-growing climbing plants, then you should turn your attention to annual climbers. It is simply extraordinary what a humble seed can grow to in the course of a year.

You come to expect the reliably exponential growth from perennials, which have years, sometimes decades in the ground to establish themselves and improve their performance year on year. But climbing annuals simply get one shot, and so they don't save anything till later, throwing out all of their best performances in one season.

Oftentimes, because summer is when these climbing annual plants do their growing (and flowering), they reach their absolute best in fall, when they are in full theatre mode and the rest of the garden is packing up for the season. So if you're looking to extend the season in your garden, then these are really just vital. Here are the five climbing annuals you should be growing.

1. Morning Glory (Ipomoea purpurea)

Ipomoea, known as 'Morning Glory' is a phenomenally fast-growing flowering vine that can grow up to 10ft tall in one growing season.

It is technically a short-lived perennial, but it is most commonly grown as an annual, since most cultivated varieties will die as soon as temperatures get cool. If you live in USDA Zones 9-11 you may be lucky enough for it to come back post-winter, but on the whole, it will last one season. Though seeds are cheap and very easy to grow, that really doesn't matter.

The vines like to twine around a trellis, fence, or an obelisk, and it's worth bearing in mind how tall they can get. Flowers come in a range of hues, from cerulean blue to deep velvety purple and pale baby blue. My favorite of all of the colors is the Carnevale di Venezia Morning Glory Seeds, which are available from Burpee, and really do bring a carnival of color to your garden.

Height: 6-10ft

Aspect: Full sun, preferring south-facing or west-facing walls. Won't tolerate north-facing walls. 6-8 hours of sunlight per day is required to help the plant flourish.

Where to buy: You can purchase mixed morning glory seeds from True Leaf Market

2. Sweet peas (Lathyrus odoratus)

In my opinion, there is no point in having a summer without sweet peas. They are the most joyful little plants, grow very fast up teepees, arches, and tripods, and, since they are cut and come again flowers, the more you pick them for putting into vases in the house, the more they will flower.

Even though they are simple annuals, which die at the end of the season, they are very hardworking plants, and always humming with bees and butterflies. They're modestly priced and, if you get a range of different sweet pea varieties, you will ensure that you have a succession of blooms, often right through summer and into the depths of winter.

One of the easiest flowers to grow from seed, so it is worth getting a few different varieties and finding your favorites. Lathyrus odoratus ‘Matucana' is beloved amongst sweet pea fanatics for its unbelievable room-filling fragrance.

Height: Up to 12ft

Aspect: Full sun

Where to buy: If you are new to growing sweet peas, then I recommend a sweet pea mix like this one available at Burpee

3. Purple Bell Vine (Rhodochiton)

Another mesmerising annual climber that is technically a perennial native to Mexico, but unless you enjoy high temperatures through the winter months, it will grow as an annual. Though it is so fast-growing, it is well worth it.

Purple bell vine is one of the longest-flowering climbers you can grow. Remarkably, it flowers in spring and continues to produce flowers until late November. My Rhodochiton plant, which sits against a warm wall in a sheltered spot in my sunny London garden, still blooms optimistically right through to Christmas.

It is one of the best climbers to attract hummingbirds, and so too the honeybees and butterflies adore it for its near constant supply of nectar.

Height: 2.4m (8ft)

Aspect: On a climbing support in full sun or part shade

Where to buy: You can purchase packets of purple bell vine seed from Eden Brothers

4. Nastertium (Tropaeolum)

There are so many terrific nasturtium varieties, one can get quite obsessed with growing them. They grow so fast, you can even sow them in summer and still expect summer blooms. If you are a fairly idle gardener, then happily, knowing how to grow nasturtiums is wonderfully simple; they require very little to no attention at all.

Nasturtium 'Spitfire' is such a riot of color; visitors to your garden will obsess over it for hours. Believe me. You can buy modestly priced Nasturtium 'Spitfire' seeds from Burpee, and they will grow even in shady borders and pots. Another achingly beautiful variety is Nasturtium 'Empress of India', which can be purchased from Burpee. Empress of India has deep moss green and crimson leaves, and ruby colored flowers. It climbs and trails, and garden birds adore it.

Height: The height of nasturtiums will depend of the variety you grow, though most climbers will grow to around 2-3ft.

Aspect: Full sun

Where to buy: You can purchase a range of nasturtium seeds from Eden Brothers.

5. Thunbergia (Black-eyed Susan Vine)

Thunbergia, often referred to as 'black-eyed Susan vine', is a tremendous annual climbing plant, flowering profusely until your first hard frost, and covered practically from root to tip in masses of flowers, even at a very early age.

Not to be confused with the daisy-like 'black eyed Susan', which comes from the sunflower family (Thunbergia rather than Rudbeckia). Thunbergia is a vigorous, fast-growing annual that adds vertical interest and delivers it fast.

Looks fabulous in a sunny cottage garden border and will ramble and twine up trellises, obelisks, fences, and hanging baskets. I grow Thunbergia and purple bell vine together, and it looks extraordinarily beautiful.

Height: 3-4ft

Aspect: Preferably a full sun position, but can tolerate a small amount of shade

Where to buy: There are several colors to consider, not just the garish canary yellow that you often find; the colors range from earthy terracotta to darkened bronze hues. My favorite is the gentle apricot-rose hue of the very tasteful 'African Sunset' with its characteristic dark eye.

Shop climbing annual supports

These five climbing annual plants are some of the best annual flowers, along with other must-grows like cosmos, zinnias, and stocks. The key is to deadhead regularly to prolong their flowering period, but other than that they require very little work.

If you love what you've grown, you can even try collecting the seeds to sow again the following year.