Seed-starting planner
Give it your average last frost date. It works backwards to when to sow, when to start hardening off and when to plant out.
Your dates
Enter your average last frost date to see your dates. Not sure? Ask your local gardening group or extension office.
How the dates are worked out
- Plant out: tender crops (tomato, pepper, aubergine, cucumber, squash, melon) go out on or after your last frost date. Hardy crops (brassicas, lettuce) can go out earlier; the planner assumes two weeks before the last frost as a rule of thumb, and you can change it for each crop.
- Sow indoors: seed to transplant takes the number of weeks given in Table 1 of Clemson Cooperative Extension's guide: tomato and aubergine 6 to 8, pepper 8 to 10, squash, cucumber and melon 3 to 5, brassicas and lettuce 5 to 7. The planner gives the window between the earliest and latest sowing date.
- Hardening off: the RHS and Clemson both give two to three weeks, so the planner starts it two to three weeks before planting out.
- Frost dates are averages. Watch the forecast, keep fleece to hand and use your own judgement if spring is late.
- Your frost date is remembered in this browser only; nothing is sent anywhere.
Not sure of your last frost date? Ask a local gardening group or your regional extension service or garden club. Then read about hardening off and transplanting.