What can I plant now?

Month-based planting advice is written for one climate and is wrong almost everywhere else. Two local numbers — your last spring frost and your first autumn frost — convert any packet's instructions into dates that actually work for your garden.

What you'll need

• Local frost dates
• Soil thermometer (optional)
• Seed packets (optional)

Step by step

1. Find your average last and first frost dates.Local data, not national. These two dates define your growing season and every sowing decision follows from them.
2. Read the packet in terms of frost, not months.Most say something like 'sow six weeks before the last frost' or 'sow after all risk of frost'. Counting back from your own date is what makes that accurate.
3. Check soil temperature rather than air temperature.Most seeds need soil above about 7°C, and warm-season crops want 15°C or more. Cold wet soil is why early sowings rot rather than germinate.
4. Late winter and early spring: start indoors.Tomatoes, chillies, peppers and aubergines need a long season and warmth. Onions, leeks and early brassicas can also start under cover.
5. Mid spring: sow hardy things directly.Carrots, beetroot, peas, broad beans, radish, spinach and salad. All tolerate cool soil and a light frost.
6. Late spring, after the last frost: plant out tender crops.Beans, courgettes, squash, sweetcorn, and anything raised indoors — hardened off first. A single frost kills all of them.
7. Summer: sow successionally and start autumn crops.Salad and radish every couple of weeks, plus overwintering brassicas, leeks and winter salads sown now for later.
8. Autumn: plant garlic, overwintering onions and broad beans.They need the cold period, and autumn planting gives a much earlier crop than spring. Also the time for bulbs and bare-root trees and shrubs.

Tips

• Keep a record of what you sowed and when, and what happened. After two seasons your own notes are more accurate than any general guidance.
• A cheap soil thermometer removes most guesswork about whether it is too early. Cold soil is the commonest cause of failed early sowings.
• If you sow too early, sow again in two weeks. A second sowing frequently overtakes a struggling first one.

Common mistakes

• Following month-based advice from a different climate — Sowing dates depend on local frost dates and soil temperature, which vary enormously. A calendar written elsewhere is simply wrong for your garden.
• Sowing into cold wet soil — Seeds rot rather than germinate. A soil thermometer, or simply waiting two weeks, produces far better results.
• Planting tender crops out before the last frost — Beans, courgettes and squash are killed outright by a single frost. There is no rushing this date.

Questions people ask