Squash needs warmth and a long season — here's exactly when to sow indoors and when to plant outside, with variety picks for UK conditions.
Ready to start growing? Read our full How to Grow Squash UK →
Sowing dates and growing advice verified against RHS guidance by the SoilCommander Growing Team.
Squash Planting Calendar
| Task | Timing | Notes |
|---|---|---|
| Sow indoors | April – May | 18–20°C; sow on edge in individual pots |
| Transplant outdoors | Late May – June | After last frost; harden off for 1–2 weeks first |
| Harvest (summer squash) | July – October | Pick regularly at 10–20cm |
| Harvest (winter squash) | September – October | Cure in a warm, dry place for 10 days before storing |
UK Variety Picks
- Crown Prince — RHS AGM, excellent storage, blue-grey skin, superb flavour
- Butternut Waltham — classic butternut, suits UK if given a warm summer
- Uchiki Kuri — small red onion squash, reliable in the UK, sweet flesh
- Defender — summer courgette/squash type, very prolific, pick young
Browse all sowing dates in the UK vegetable planting calendar · Explore all UK vegetable growing guides
Relevant next steps
Plan The Timing Before You Sow
Use the planting window with a planner, seed-starting setup, and the full calendar so dates stay practical for your garden.
Plan the next step
Use the printable UK Vegetable Garden Planner to turn this guide into sowing dates, bed layouts, and weekly garden tasks.