How to grow sweet peas
All you need to know about sowing and growing fragrant sweet peas, in our practical Grow Guide.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow | yes | yes | yes | yes | yes | yes | yes | |||||
| Plant | yes | yes | yes | |||||||||
| Flowers | yes | yes | yes | yes | yes | |||||||
| Cut back | yes | yes |
Perfect for picking, fragrant sweet peas are easy to grow and come in a range of beautiful colours. You can grow them in pots or in the ground, training them up a frame for a beautiful display. Plant sweet peas near a seating area so you can smell them as you sit and relax in the garden. Or pick some for the vase – even a small amount can fill a room with fragrance.
How to grow sweet peas at home
Plant sweet pea seeds in autumn or spring. When plants are 10cm tall, pinch out the tips to encourage bushy growth. Plant out in mid-spring and keep well watered. Most varieties have tendrils that will 'self-cling' to supports, but some sweet peas will need tying in.
Start feeding sweet peas with a high potash fertiliser (such as tomato food) when flower buds appear. Regular picking encourages more flowers to form, so keep picking those blooms for the vase.
Growing sweet peas: jump links
- Planting sweet peas
- Caring for sweet peas
- Growing sweet peas: problem solving
- Where to buy sweet peas
- Sweet pea varieties to grow
More on growing sweet peas:
Where to grow sweet peas
Plant sweet peas in an open, sunny position in a well-drained but moisture-retentive soil. Sweet peas are well suited to growing in pots – make sure you use a good, peat-free compost with a slow-release fertiliser mixed in.
How to sow sweet peas
Sweet peas are easy to grow from seed in either autumn or spring. If sowing in autumn ensure you have the room to grow them on in a frost-free place until spring.
Sweet pea seeds germinate relatively easily. But you can help activate germination by nicking the seed coat with a knife, avoiding the 'eye' area. Either sow seed in 9cm pots (3 to a pot), in root trainers or trays. Sow the seed in a good quality, peat-free compost, and place in a cold frame or greenhouse.
Watch Monty Don's video guide to growing sweet peas from seed:
Planting out sweet peas
Plant out your sweet peas from late May, once all risk of frost has passed. Before planting, harden them off by putting them out in the day and returning them to a frost-free place at night. Pinch out the tips of young sweet pea plants when they reach about 10cm tall, to encourage bushy growth.
You can buy sweet pea plug plants in spring. Plant them in fertile soil beneath a support, such as a wigwam made of bamboo canes. Most sweet peas will grow to about 2m in height. Water in well until they’ve put on good growth. Space sweet pea plugs or pots about 20cm apart - don't worry about separating individual plants.
Watch Monty as he plants out sweet peas and explains how to plant out shop-bought plants. Learn why it's best to plant them out only once the soil has warmed up, and the benefits of giving them a good drink after planting:
Where to buy sweet peas online
How to care for sweet peas
Sweet peas require training up a suitable support and can be grown as cordons.
Watch David Hurrion's No Fuss video guide to tying in sweet peas:
Start feeding with a high potash fertiliser, such as tomato food, when flowers appear. Regular picking will encourage more flowers and prevent plants from setting seed. Water sweet peas growing in pots, and during very dry weather.
Find out how to prolong your sweet pea crops, in Monty Don's practical video. Monty explains how picking at regular intervals will keep your plants flowering right through summer and into September. You'll also have a steady supply of cut flowers for the house:
Growing sweet peas: problem solving
Young sweet pea plants are prone to slug and snail damage. Try using beer traps, copper bands, or the biological control, Nemaslug, to deter them. Find out more about keeping slugs and snails away.
Sweet peas can sometimes become leggy. Here, David Hurrion explains how to save them:
In hot, sunny weather, the soil around plants can become especially parched, and for sweet peas, can cause them to drop their flowers. Take a look at this Quick Tips video with Catherine Mansley, BBC Gardeners' World Magazine, as she offers advice on how to both treat and prevent this problem:
Saving sweet pea seeds
Seed can be collected in early September. Leave the seed pods on the plants until they have turned a paper bag colour. Collect them on a dry day, remove them from their pods and store in paper bags in a dry place until you a ready to sow them.
Advice for buying sweet peas
Here’s our guide to buying sweet peas, including where to buy sweet peas.- Bear in mind that some sweet peas have a stronger fragrance than others. If you're keen on scent, check the variety to make sure it won't disappoint
- Buy a mix of colours to grow together – different coloured sweet peas make the best looking posies
- Check the height and spread of your sweet pea vareity, and how much support it needs to grow. Knowing how to care for your sweet peas before they arrive will stand you in good stead for a brilliant sweet pea harvest
Where to buy sweet peas online
Great sweet pea varieties to grow
- Lathyrus vernus ‘Alboroseus’ – a hardy perennial bush-forming sweet pea that has tiny pink and white flowers in April. Reaches 35cm in height and spread
- Lathyrus latifolius ‘White Pearl’ – perennial climber with pure-white flowers from June to late August. Reaches a height of 2m
- Lathyrus odoratus ‘Matucana’ – hardy annual that is hugely popular and fondly known as the old-fashioned sweet pea. It has scented two-tone purple flowers in summer and is ideal for picking
- Lathyrys odoratus 'Lipstick' (pictured) - a wavy-edged, Spencer type with good scent
- Lathyrus odoratus ‘Lord Nelson’ – hardy annual grown for picking. Blue flowers with a highly rated scent in summer. Plants reach 2m
- Lathyrus odoratus ‘Painted Lady’ – hardy annual grown for picking. Bi-coloured blooms of pale and dark pink. Highly scented old-fashioned type. Great for early flowers
Frequently asked questions
Why are the leaves on my sweetpeas turning yellow?
Yellowing sweet pea leaves are usually caused by over-watering. On dull days, plants don't need watering every day as this can cause root rot. Your sweet peas may be salvagable – stop watering immediately and ensure they're not sitting in any water. Then, if plants recover, start watering again, gradually, checking the compost first to make sure it's not still moist.
Help! My sweet peas are leggy!
Leggy sweet peas are usually the result of too little light. If you can, move them to a brighter spot, and turn the pots regularly so the plants don't lean too much in one direction. Once plants are 10-15cm tall, use your thumb and forefinger to pinch out the tips. This will encourage bushy growth and should stop them being leggy.
Do sweet peas trail well?
Sweet peas are climbing plants and therefore don't trail well. If you try to grow sweet peas in a hanging basket you may find that they trail a little but then stop growing, or will put on growth towards the base, rather than at the tips. Some dwarf or patio varieties of sweet pea are said to trail better than conventional types, and could be worth a try.
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