What to plant in August in the UK

Worked out for 40 cities from their own weather and frost dates, by zone.

What to sow and plant in August in the UK, by zone: frost-free, highs of 22–28 °C (London and Cambridge): broad bean, peas, onion, spinach, lettuce and 17 more; frost-free, highs of 16–22 °C (Manchester, Edinburgh and 36 more): broad bean, peas, onion, spinach, lettuce and 17 more.

In the UK, August is summer.

Frost-free, highs of 22–28 °C: London and Cambridge

In August, on average, these cities have highs of 23 °C and lows of 14 °C, 50 to 52 mm of rain on 10 days; the day lasts 14 h 40 min to 14 h 44 min (on the 15th).

No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Broad bean, peas, lettuce, carrot, cabbage, broccoli, Swiss chard, beet, parsley, cilantro, arugula, chamomile, chickpea, dill, kale, kohlrabi, mustard greens, parsnip	all
plant sets	Onion, shallot	all
start indoors, plant out in September	Spinach, cauliflower	all

Compared with July: new — spinach; no longer sown — leek, watermelon, pumpkin, sweet corn, basil, bok choy, borage, Brussels sprouts and 7 more.

Not starting in August: tomato (March, started indoors), bell pepper (April, started indoors), zucchini (April, started indoors) and green beans (May, sown direct) — dates for Cambridge.

Ready to harvest in August in Cambridge, if sown in the right month: broad bean (May), peas (June), lettuce (June), carrot (June), cabbage (April), broccoli (May), Swiss chard (June) and beet (June).

Frost-free, highs of 16–22 °C: Manchester, Edinburgh, Birmingham, Glasgow and 34 more

In August, on average, these cities have highs of 17 to 22 °C and lows of 10 to 17 °C, 54 to 139 mm of rain on 10 to 20 days; the day lasts 14 h 33 min to 15 h 20 min (on the 15th).

No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Broad bean, peas, lettuce, carrot, cabbage, broccoli, Swiss chard, beet, parsley, cilantro, arugula, chamomile, dill, kale, kohlrabi, mustard greens, parsnip	all
plant sets	Onion, shallot	all
sow direct or start indoors, plant out in September	Spinach	all
sow direct	Radish, daikon	Manchester, Edinburgh, Birmingham and 28 more
start indoors, plant out in September	Cauliflower	Bristol, Cardiff, Liverpool and 12 more
start indoors, plant out in October	Leek, Brussels sprouts	Brighton and Plymouth
sow direct	Chickpea	Leicester, Coventry, Nottingham and 6 more
sow direct	Turnip	Glasgow, Belfast, Plymouth and 6 more
start indoors, plant out in September	Chicory	Cardiff, Liverpool, Swansea and 1 more

Compared with July: no longer sown — sweet corn, bok choy, borage, chayote, corn, Florence fennel, kiwano and Napa cabbage.

Not starting in August: tomato (March, started indoors), bell pepper (no month outdoors by these rules), zucchini (April, started indoors) and green beans (May, sown direct) — dates for Stoke-on-Trent.

Ready to harvest in August in Stoke-on-Trent, if sown in the right month: broad bean (May), peas (June), lettuce (June), radish (July), carrot (June), cabbage (April), broccoli (May) and Swiss chard (June).

How we work it out

For each city we use its average weather in August and the months after (highs, lows and rain for 2016–2025, ERA5 reanalysis via Open-Meteo) and its average frost dates. A crop starts in August if the month's mean temperature reaches the minimum soil temperature for germination on its card (we use the mean air temperature as a stand-in for the soil's) and if, over its first months (up to three), the average highs stay within its group's range, with no frost for crops that cannot take it. Crops started indoors count from the month they are planted out.

Temperature groups from Colorado State University Extension: cool-season crops prefer 16–27 °C and lose quality in heat; hardy ones grow in days as cool as 4 °C, semi-hardy ones from 4–10 °C (we use 10 °C); warm-season crops need days above 13 °C, and the most tender (tomato, pepper, aubergine, melon, watermelon, squash) above 16 °C, up to 35 °C. Crops the guide does not name go into the stricter group by their frost hardiness. Broad beans, which the guide does not name, count as hardy: hardy varieties are sown in autumn and overwinter (RHS). Garlic and bulbs: a month before the first frost, and later only while the ground is not frozen (as on each city's page). French beans, courgettes and outdoor tomatoes follow the RHS instead, in months without frost: French beans and courgettes sown outdoors in late May or early June, courgettes also started indoors in April or May; tomatoes started indoors from late March to early April and planted out in June where its average highs reach 16 °C.

This is a general rule from averages: your garden can be a week or two earlier or later, and a greenhouse or a cold frame brings the season forward. Greenly works out the dates for your location.

What to plant in August in the UK

Frost-free, highs of 22–28 °C: London and Cambridge

Frost-free, highs of 16–22 °C: Manchester, Edinburgh, Birmingham, Glasgow and 34 more

How we work it out

Other months in the UK