How to grow Sweet Pea in the UK
Lathyrus odoratus
Sweet Pea (Lathyrus odoratus) is a flower that grows well in UK gardens. Pick every few days — let pods set and flowering stops. Soak seed overnight before sowing. This guide covers when and how to sow Sweet Pea, the soil and position it likes, watering and feeding, companion planting, and when to harvest.
When to sow & grow Sweet Pea
Sowing and harvest window through the year (UK):
Jan | Feb | Mar Sow | Apr | May Plant | Jun | Jul | Aug | Sep | Oct Sow | Nov | Dec |
Soil, position & care
- Soil
- Any reasonable, moisture-retentive but free-draining soil
- Soil pH
- 6.0–7.5
- Position
- Full sun, rich soil
- Sowing depth
- 1.5 cm
- Spacing
- 15–20 cm up a support
- Sowing
- Sow Oct or Feb–Mar; soak/chip seed; pinch out tips
- Growing
- Feed and water well; grow up canes or netting
- Harvest & upkeep
- Pick flowers every few days and deadhead — stop picking and it stops flowering
- Watch for
- Slugs, aphids, mice eating seed
Companion planting for Sweet Pea
Grows well with:
Keep apart from:
Add Sweet Pea to your free 12-month plan and get watering & sowing reminders — no sign-up needed.
Sweet Pea FAQs
When should I sow Sweet Pea in the UK?
In the UK, sow Sweet Pea in March, October. Sowing across these months gives the plant the right soil temperature and day length to establish well.
What grows well with Sweet Pea?
Sweet Pea grows well alongside Rosemary. Good companions can deter pests, attract pollinators or make better use of space.
What should you not plant near Sweet Pea?
Keep Sweet Pea away from Chives, Florence Fennel, Fennel, Garlic, Leek, which can compete with it or share pests and diseases.
How much sun does Sweet Pea need?
Sweet Pea prefers full sun (6+ hrs direct).
Is Sweet Pea easy to grow?
Easy — good for beginners. Pick every few days — let pods set and flowering stops. Soak seed overnight before sowing.