How to Grow Sweet Pea
Annual
Sweet peas are classic British climbing annuals, grown for their romantic flowers and often wonderful perfume. They thrive in a sunny, well-prepared patch and reward regular picking with weeks of bloom. Modern varieties offer many colours, while old-fashioned types remain favourites for their scent and informal charm.
Planting
Sow in autumn, from October to November, in a cold greenhouse or sheltered cold frame for sturdy early plants. Alternatively sow from January to March in deep pots or root trainers, then plant out after plants are hardened off. Direct sowing in April is possible in a prepared bed. Set plants 15 to 20 cm apart beside canes, netting or a wigwam at least 1.8 m high. In colder areas, delay outdoor planting until severe frosts have eased.
Care
Grow sweet peas in full sun and keep soil evenly moist, especially as buds form. Mulch with garden compost and water at the base during dry spells. Tie in wandering shoots gently as they climb. Pick flowers every few days, before seed pods develop, because pod formation slows further blooming. Remove faded flowers and yellow leaves promptly for a neat display.
Bloom time
Autumn- or early-sown plants commonly flower from June to September; direct-sown plants begin later. In sheltered southern gardens, bloom may continue into October, whereas cool northern weather can bring the season to a close earlier.
Garden uses
Train sweet peas over a wigwam, fence netting or an obelisk in a cutting garden, vegetable plot or sunny border. Their stems are made for small posies and indoor fragrance. They also cover vertical supports without the permanent commitment of a shrub or perennial climber.
Tips
Choose long-stemmed, scented varieties carrying an RHS Award of Garden Merit (AGM) for reliable cutting. Do not use short supports: plants quickly outgrow them. Sweet pea seeds and pods are not for eating, so keep them clearly separate from edible peas if children help in the garden.
Growing Sweet Pea: frequently asked questions
How do I grow sweet pea in the UK?
Sow in autumn, from October to November, in a cold greenhouse or sheltered cold frame for sturdy early plants.
When does sweet pea flower?
Autumn- or early-sown plants commonly flower from June to September; direct-sown plants begin later.
How do I care for sweet pea?
Grow sweet peas in full sun and keep soil evenly moist, especially as buds form.
General guidance for UK gardens. Timing and hardiness vary by region and season; the RHS or a local garden centre can advise for your area. Page updated 19 Sep 2026.