How to grow sweet peas

Val Bourne

These cut-and-come-again annual climbers are easily grown and they provide summer flowers for the house, as well as fragrance and all-important vertical presence. Read our tips for growing sweet peas.



Sweet peas are ‘cut-and-come-again’ annual climbers. They are easily grown and sweet peas provide summer flowers for the house, as well as fragrance and all-important vertical presence.

Colour varieties range from sultry dark-red through to pastel summer shades of blue, lavender and pink and there are striped and flaked varieties.

Where to plant

Sweets peas thrive in fertile, well-drained, sunlit east or south-facing borders and beds.

When to plant

Although growers of exhibition sweet peas sow in the autumn, early March is plenty soon enough for the ordinary gardener. Buy good quality seeds and try to avoid mixtures so that you know what you’re growing.

How to plant

Fill nine-inch deep pots with a good seed-sowing compost such as John Innes no. 1 and water the pot well before you sow.

Space the seeds out well (a maximum of 7 to a 4in pot) and cover with between an inch of compost.

Place in a cool greenhouse and protect from mice with wire.

Once the plants reach 4in in height, remove them from the greenhouse and harden them off by putting them outside for a week.

Prepare the ground by digging thoroughly and try to add a slow release fertiliser such as blood fish and bone, growmore or poultry-based manure – powdered 6X or pellets.

Put in the support. Twiggy hazel sticks are the best, but canes and a net will do.

Loosen the roots of the sweet peas and, using a trowel, plant out the sweet peas roughly nine inches apart in a light and sunny position.

Pinch them out straight after planting so that they form bushy plants and then water them in well.

Water well if dry – using warm water from a can – until the sweet peas are mostly up the supports. However do NOT over water.

Religiously pick your sweet peas every other day and always remove any seed pods – this keeps them in flower.

Regular picking, together with generous provision of food and water, will give a prolonged and colourful display.

How to grow sweet peas for exhibition

Autumn sowing is vital – this gives the most developed roots and enables the earliest planting in the garden.

Remove all but the strongest stem.

Remove tendrils and tie and support the main stem using wires or raffia.

The resulting flower stems should be longer and stronger and the number, size and quality of blooms per stem will be maximised.

Arranging and cutting sweet peas

There’s no special technique. The peas are cut, preferably early in the morning, and put straight into a bucket of water.

Pastel flowered sweet peas can be arranged in soft colour combinations on their own in a simple jug.

Blue and lavender shades mix well with the tiny lime-yellow, frothy stars of Alchemilla mollis. Many small-flowered annuals including Clary (Salvia horminium), larkspur (Consolida ambigua), cornflowers (Centaurea cyanus) and small-flowered scabious combine well with them too.

Darker sweet peas, including the flaked and striped varieties, look stunning with the lacy, white heads of annual Ammi majus and Ammi visnaga. It’s worth growing both because Ammi majus is taller and earlier and Ammi visnaga is shorter and later. Adding some dark tassels of amaranthus (love-lies -bleeding) makes this combination even more dazzling, especially if you use a pale container.

When they bloom

Sweet peas start to flower in May-June

When to deadhead or cut back

Dead head the sweet peas as they go and make sure you cut back after flowering.

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The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.