Sweet Pea
Lathyrus odoratus
Sweet peas are a quintessentially British cottage garden annual climber, grown for their exquisite fragrance and abundance of pastel-coloured flowers from June to September. They climb using twining tendrils and reach up to 2 metres on wigwams, obelisks, or cane supports. Regular picking encourages continuous flowering. They are hardy annuals, easily raised from seed sown in autumn or spring.
Full growing guide
How to Grow Sweet Peas from Seed
How to grow sweet pea
Sow seed in October or November in root trainers in a cold frame, or in March to April on a windowsill. Nick the seed coat or soak overnight to speed germination. Plant out after hardening off in late April or May, spacing 15-20 cm apart. Prepare the soil deeply by digging a trench and incorporating well-rotted compost or manure the previous autumn. Sweet peas need rich, moist soil and consistent watering. Provide bamboo canes, netting, or a wigwam for support. Feed fortnightly with a high-potash liquid fertiliser once flowering begins. Pick flowers every two to three days to prevent seed pods forming, which stops flowering.
Pruning
No traditional pruning required as sweet peas are annuals. Pinch out the growing tips when seedlings have three pairs of leaves to encourage bushy, multi-stemmed plants. Remove tendrils if growing for exhibition to encourage longer, straighter stems. Pull up plants after flowering ends in September.
Propagation
- Seed
Common problems
- Powdery mildew
- Aphids
- Slugs on young plants
- Bud drop in hot weather
Good companions
Related guides
How to Grow Sweet Peas from Seed
How to grow sweet peas from seed in the UK, with easy tips on autumn or spring sowing, pinching out, giving them something to climb and picking often.
When to Sow and Plant Sweet Peas in the UK
When to sow sweet peas in the UK and when to plant them out. Compare autumn, winter and spring sowing, with a month-by-month calendar to follow.
Cottage Garden Planting Plan for the UK
How to plan a cottage garden border: the classic plants, how to layer them, colour ideas and a ready-made planting plan for a sunny UK border.