How to grow zinnias – brighten up your garden with these summer flowers

Find out how to grow zinnias to bring both color and wildlife into your garden

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Thinking about how to grow zinnias? We're here to help.

Growing zinnias is an easy way to add beauty and color to your flower beds. Closely related to the sunflower and part of the daisy family, this beautiful bloom is native to the dry grasslands of the Southwestern states and Mexico. Not only is it a firm favorite in our flower beds but its also loved by wildlife including bees, butterflies and ladybirds.

See: Garden ideas – charming ways to get a characterful look

When it comes to advise on how to grow zinnias, author and garden expert Melinda Myers recommends 'full sun and well-drained soil. Once established they are drought tolerant making them an excellent choice for containers and busy gardeners.'

Read on to find out how to grow zinnias in your own garden for statement blooms throughout the summer season.

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What is the best way to grow zinnias?

If you're wondering how to plant a flower bed with zinnias, the answer is from seed. However, there are some key rules to follow in order to produce successful blooms. Zinnias must be planted in situ - meaning you sow the seeds in the exact spot you want your finished flower as they dislike being transplanted or having their roots disturbed. 

 'Simply direct sow the seeds in a sunny spot after the last frost. Add a couple inches of mulch or compost and a bit of fertilizer,' advises Kristin Winterbottom from Parkseed 'Keep the soil moist by watering at the base of the plants. Cut blooms frequently for arrangements or simply pinch off spent blooms.' 

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‘Alternatively you can sow into modules, so there’s no pricking out, and plant out when still small with only a pair or two of true leaves. That way you minimise root handling,’ recommends plantswoman Sarah Raven in her blog.

Discover what else to grow in your beds with these beautiful ways flower bed ideas.

If you're wondering 'Should I soak zinnia seeds before planting?' then the answer is yes. Soaking your seeds will increase the speed of propagation. However, you need to be careful not to leave the seed in water for too long as the seed will start to rot. Soak your seed for between 8-12 hours. 

One of the most common mistakes when it comes to how to grow zinnias is planting them too early. Zinnias won't survive any frost, so only sow your seeds once all risk of frost is over and the cooler nights have passed.

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You can also grow zinnias in pots – the same rules apply: plant and grow in situ and only place your pot outside when the frost is over. If you are growing your zinnias in pots, you can sow them earlier if you have a warm greenhouse in which they can germinate and start to grow.

Whether you grow in pots, the ground or a raised bed, it is worth mulching them with straw or bark in order to retain moisture which is a particular challenge in the hot conditions that zinnias love. 

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How to grow zinnias from cuttings

Growing zinnias from cuttings is an excellent way to duplicate your favorite plants, though these have less success than growing straight from seed. Take cuttings from zinnias the same way you would with any other tender annual – cut around  2½-3 inches of leaf and stems and put in a small pot of two-third compost and one-third grit. Water well and place in a warm spot – either the greenhouse or a windowsill - and your cutting should root with two-three weeks.

Where is the best place to plant zinnias?

The best place to plant zinnias is in a sunny spot in the garden. Originating from South-Western America and Mexico, zinnias thrive in warm climates. If you live in a cooler part of the world, then growing them undercover in a greenhouse will offer more success.

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Do zinnias come back every year?

No, zinnias don't come back every year as they are annual plants. This means that the flowers complete their entire lifecycle in one year.

Zinnias are very vulnerable to frosts and will die soon after the first frost. If you want to have zinnias in your garden every year, then you will have to resow annually. However, since zinnias are so easy and low-maintenance to grow it's not too much trouble, especially for the reward of the beautiful blooms come the late summer months. 

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How to grow zinnias for a wildlife garden

Zinnias are loved by bees and butterflies. 'Blooming in the late summer and early autumn these pretty flowers will add some delightful color to your garden in the late season and keep the bees returning for months,' says Lucia Polla of Serenata Flowers.. Underplant zinnias with petunias and Erigeron karvinskianus - which also thrive in hot, full-sun conditions – to offer a real smörgåsbord for any visiting critters.

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Do I need to pinch out zinnias?

You can pinch out zinnias to promote a strong and healthy plant. By pinching out the growth tip early on in the season will encourage the plant to branch out and create more flower stems. However, it is not essential that you pinch out zinnias. They will naturally branch out throughout the season, especially when you are deadheading or cutting flowers for the vase as this has a similar effect.

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How to grow zinnias as cutflowers

If you’re looking for a bloom to use as a cut flower then zinnias are definitely for you.  Producing a long stemmed solitary flower in a wide range of colors from white and yellow through to orange, red, purple and lilac, zinnias are great cutflower bloom.

'Nothing says summer like a handful of cheerful zinnias. They are one of the easiest cut flowers to grow, thrive in heat and the more you pick them the more they bloom. They are perfect for beginning gardeners.' says Erin Benzakein author and founder of Floret Flowers.

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Do you deadhead zinnias?

Yes, you should deadhead your zinnias to keep them flowering throughout the whole season. You can either deadhead the blooms off as they start to fade or you can cut them off slightly earlier and then display them in a vase to get double the pleasure from your plants.

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This feature was created by H&G's sister brand, Period Living magazine 

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