How to grow sweet peas

How to grow sweet peas

All you need to know about sowing and growing fragrant sweet peas, in our practical Grow Guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Sow
Sow

Do not Sow in January

Do not Sow in February

Do Sow in March

Do Sow in April

Do Sow in May

Do not Sow in June

Do not Sow in July

Do not Sow in August

Do not Sow in September

Do Sow in October

Do Sow in November

Do not Sow in December

Plant
Plant

Do not Plant in January

Do not Plant in February

Do not Plant in March

Do Plant in April

Do Plant in May

Do Plant in June

Do not Plant in July

Do not Plant in August

Do not Plant in September

Do not Plant in October

Do not Plant in November

Do not Plant in December

Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does flower in June

Plant does flower in July

Plant does flower in August

Plant does flower in September

Plant does flower in October

Plant does not flower in November

Plant does not flower in December

Cut back
Cut back

Do not Cut back in January

Do not Cut back in February

Do not Cut back in March

Do not Cut back in April

Do not Cut back in May

Do not Cut back in June

Do not Cut back in July

Do not Cut back in August

Do not Cut back in September

Do Cut back in October

Do Cut back in November

Do not Cut back in December

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.

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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.

More on growing sweet peas:


Where to grow sweet peas

How to grow sweet peas - where to grow sweet peas
How to grow 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

How to grow sweet peas - sowing sweet peas
How to grow sweet peas – sowing 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

How to grow sweet peas - planting out sweet peas
How to grow sweet peas – 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.


How to care for sweet peas

How to grow sweet peas - tying in sweet peas
How to grow sweet peas – tying in 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.


Growing sweet peas: problem solving

How to grow sweet peas - problem solving
How to grow 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.

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. 

Wooden garden trug

Great sweet pea varieties to grow

How to grow sweet peas - sweet peas to grow
How to grow sweet peas – sweet peas to grow
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  • 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