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how to grow sweet peas

How to grow sweet peas

Sweet Peas are a cottage garden classic producing beautiful blooms with the most gorgeous scent. You can train them onto a plant support to create a really impressive column of fragrant, summer colour, and they make excellent cut flowers.

Annual Sweet Peas are often beautifully fragrant but last only one season, while Everlasting Sweet Peas are herbaceous perennials returning year after year but with less fragrance than their annual cousins.

How to sow sweet pea seeds

Growing sweet peas couldn’t be easier. You can sow them into small pots of compost in autumn and overwinter the young plants in a cold frame or cool greenhouse. Or, you can wait until spring and start planting your sweet peas in pots, or sow directly into the ground.

Before you sow them you can soak your sweet pea seeds in tepid water to rehydrate them. It helps them get off to a quicker start but it isn’t essential as they will still germinate well in moist compost. If you soak them overnight you will notice that they swell up and turn a lovely chestnut colour. Use a good quality compost and sow several sweet pea seeds to a pot.

Sow them about 1cm deep, cover the seed with compost and water them well. If sowing Sweet Pea seed seems like too much effort you could always buy sweet pea plug plants. Place them in a bright position and when the shoots appear keep an eye out for slugs as they love young sweet pea shoots.

sweet pea pinching

How to grow sweet pea plants

Pinching out Sweet Pea Shoots

As the seedlings grow they will start to become tall and leggy. You can encourage them to produce side shoots by pinching out the tips of the sweet peas. Simply nip off the top of the stem just above a set of leaves. This will make each plant much bushier and more robust. And the more shoots there are, the more flowers will be produced!

Transplanting Sweet Pea Plants

Once your sweet peas are growing well and the main risk of frost has passed, you can pop them outside to acclimatise them to outdoor conditions for a week or so before planting them out.

Plant your sweet peas out in a bright sunny spot in the garden that is easily accessible so that you can get to the plants to pick the flowers. Sweet peas love a rich, moist soil so dig a couple of buckets of compost into the planting area beforehand to enrich the soil and hold the moisture during dry weather. Alternatively you can plant sweet peas out in large containers on the patio. Sweet peas are climbers and will need a suitable support to grow up. Put your plant support frame into position before you start planting sweet peas. Turn each pot out and gently separate the plants. You can plant 2 or 3 seedlings in each planting hole for a nice, full display. Aim to plant each group about 15cm apart.

how to grow sweet pea plants

Tying in Sweet Pea Stems

Sweet peas climb by twining their tendrils around the sweet pea support frame, but it is helpful to guide them onto the support using sweet pea support rings.

Throughout the season you will need to keep them well watered, as dry soil will make them go to seed quicker. Make sure that you remove any faded sweet pea flowers or seedpods as soon as possible to encourage more blooms to be produced.

Don’t forget that the more that you cut, the more sweet peas flowers you will get so you can enjoy that fabulous sweet pea perfume in your home too.

Pruning Sweet Pea Plants

Once your sweet pea plants are in full flower you should regularly dead-head them to encourage more flowers to develop. Simply snip off any faded blooms or seed pods when you see them.

If you love having fresh cut flowers in your home, then sweet peas are the plants for you! They are ideal for cutting as the more blooms you cut the more they grow.

Sue Sanderson

Written by: Sue Sanderson

Plants and gardens have always been a big part of my life. I can remember helping my Dad to prick out seedlings, even before I could see over the top of the potting bench. As an adult, I trained at Writtle College where I received my degree, BSc. (Hons) Horticulture. After working in a specialist plantsman's nursery, and later, as a consulting arboriculturalist, I joined Thompson & Morgan in 2008. Initially looking after the grounds and coordinating the plant trials, I now support the web team offering horticultural advice online.