GardenCalc
One Page, Twelve Months
This is the hub for GardenCalc's month-by-month sowing resources. Each month below gets a short, honest list of what to sow in the UK, based on the same crop data that drives our interactive planting calendar and cross-checked against the RHS grow-your-own vegetable guides. For the full crop-by-crop view, with sow, plant-out and harvest bars for 30 crops and a region switch, the calendar itself is the place to go.
The Fast Crops, for When You Are Behind
Radishes are the fastest vegetable in the UK garden, ready about four weeks from sowing. Rocket takes four to five weeks, baby-leaf lettuce five to six, spinach six to eight, spring onions eight to ten. All of them can be sown little and often from March until late summer, so a short gap in a bed never stays empty for long. The Sow-Window Planner turns those speeds into dated windows for your part of the UK.
What to Sow Each Month in the UK
Timings below assume average UK conditions. Northern and high-altitude gardens run two to three weeks behind in spring; mild coastal and city gardens run ahead. If you garden in a big city, the sow-in-your-city pages give dated windows for 15 UK cities.
January
The quietest sowing month of the year. Outdoors, cold wet soil means almost nothing germinates, so the real work is planning: order seed now while every variety is still in stock. With a heated propagator you can start chillies and peppers indoors, since both need the longest season you can give them. In mild southern gardens, broad beans can go in under cloches. Harvest carries on regardless, with parsnips, leeks, winter brassicas all standing happily in the ground.
February
Still winter, but the indoor season starts properly. Sow tomatoes, peppers, chillies in a heated propagator or on a warm windowsill; they need the head start. Broad beans can be sown outdoors in mild areas under cloches, or in pots in a cold frame elsewhere. Garlic goes in now if you missed the autumn slot, as it still gets enough cold to split into cloves. Outdoors, leave the soil alone until it stops sticking to your boots.
March
The outdoor season opens. Once soil holds 10°C, direct-sow peas, carrots, spinach, radishes, rocket, spring onions, parsnips. Indoors, keep the tomatoes going and start brassicas such as cabbage and broccoli in modules. Onion sets can be planted, and first early seed potatoes go in from late March in milder areas. Frost is still a regular visitor, so hold tender crops back and keep fleece to hand for anything already up.
April
The busiest sowing month on the calendar. Direct-sow beetroot, radishes, lettuce, chard, kale, carrots outdoors. Indoors, start courgettes, squash, pumpkins, sweetcorn in pots, with French and runner beans towards the end of the month. First early potatoes should be in by now; maincrops follow mid-month. April frosts catch people out every year, so nothing tender goes outside yet. A soil thermometer settles any argument about whether a bed is ready.
May
The month the frost risk ends across much of the UK, typically mid to late May and later in the north. Once soil reaches about 12°C, direct-sow French beans and runner beans. Sweetcorn is fussier: it wants soil nearer 15°C to germinate reliably outdoors, so start it in pots in May and plant it out, or hold the direct sowing back until the warmth arrives, usually June. Plant out tomatoes, courgettes and squash once your last frost date has passed, and check that date for your postcode with the frost date calculator rather than guessing. Keep sowing salad leaves every couple of weeks so the picking never stops.
June
Sowing carries on while planting out takes over. Direct-sow beetroot, carrots, lettuce, turnips for autumn eating. Plant out leeks, celeriac, sweetcorn. Get the last tender plants in early in the month. The first proper harvests arrive too: broad beans, peas, salad leaves, the first strawberries. Watering becomes the job that decides everything from here, above all for anything newly transplanted into summer soil.
July
Peak harvest month, but the sowing year is far from over. Direct-sow beetroot, carrots, radishes, rocket, spring onions, turnips now and they crop through autumn. Keep sowing lettuce in a lightly shaded spot, as summer heat makes it bolt in full sun. Plant out the last leeks. Anything sown this month races out of the ground in warm soil, which makes July sowings some of the easiest of the year.
August
Winter lettuce, spinach, spring onions, turnips, radishes and rocket can all still be sown outdoors in August across most of the UK. What decides it is not the date but whether the crop's weeks to harvest fit before your first autumn frost, which varies by more than six weeks between regions. For the full crop-by-crop maths on what still fits, see Still Time to Sow in August?, and get your own frost date from the frost date calculator.
September
The last real outdoor sowing month. Winter spinach, lamb's lettuce and winter lettuce go in now for picking through autumn and again in spring. Radishes and rocket still fit in the first half of the month in milder areas. Towards the end of September you can start planting garlic, though October is its main month. Everything else waits for spring, so clear finished crops and get compost onto empty beds while the soil is still warm.
October
Garlic's month. Plant cloves now so they get the winter cold that makes a bulb split properly rather than growing as one round. Overwintering broad beans go in towards the end of the month in mild areas. Winter lettuce can still be sown under cloches. Beyond that, October is for clearing beds, mulching, planting spring bulbs, with the first frosts arriving in northern and inland gardens before the month is out.
November
Last calls. Garlic can still go in, and overwintering broad beans are worth a try in mild southern gardens, though they are a gamble further north. Otherwise the sowing year is done. Mulch empty beds, clean pots and tools, and check stored crops for rot. It is also the best month to look back at what worked while it is still fresh, and adjust next year's plan accordingly.
December
Nothing goes in the ground this month, and that is fine. Harvest carries on with parsnips, leeks, kale, Brussels sprouts, all of which stand through frost. The one job that pays all year is done from an armchair: order seed for the new season before the popular varieties sell out, and sketch out the beds month by month using the planting calendar.
Frequently Asked Questions
Sources: crop sowing windows per GardenCalc's own planting calendar, cross-checked against the Royal Horticultural Society's grow-your-own vegetable guides. Frost timing per Met Office HadUK-Grid 5 km gridded observations, 1991–2020, the dataset behind our frost date calculator. Contains public sector information licensed under the Open Government Licence v3.0. Disclaimer: sowing windows are guidance, not a guarantee. Check your postcode's own frost estimate and your local conditions before relying on any date for tender crops.
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