Lesson 2
Sowing and root run
Sweet peas have long roots — give them deep root-runs. Sow in long pots ('root trainers'), toilet-roll tubes, or pots at least 10 cm deep, 2–3 seeds per cell.
Best timing: autumn sow (Oct–Nov) for the strongest plants, overwintered in a cold frame; or late winter (Feb) under cover. Pinch the growing tip when plants have 4 leaf pairs to force bushy growth from the base.
Soaking the seed is optional — heritage varieties with hard coats benefit (12 hours in tepid water); modern varieties germinate fine without.
Sweet pea sowing routine
- 1Soak hard-coated heritage seeds overnight in tepid water (optional but helpful).
- 2Sow into deep pots / root trainers of seed compost, 1.5 cm deep, 2–3 seeds per cell.
- 3Keep cool (8–12°C) — too warm and they go leggy.
- 4Once 4 leaves emerge, pinch out the top growing point to force bushy side shoots.
- 5Pot on or harden off if autumn-sown; overwinter in a cold frame.
- 6Plant out at 15 cm spacing along a support after last frost — keep in trios.