What to Plant in August
in the UK

Sow in a seedbed for transplanting in late September or October. These will overwinter and give you an early spring harvest before anything else is ready.

Choose overwintering varieties such as 'Arctic King' or 'Winter Density'. Sow now for harvesting under cover from October through winter.

A hardy, peppery salad leaf that tolerates frost well. Sow direct now and it will crop through autumn and well into winter.

Sow direct or in modules. Grows fast in cool conditions — August-sown plants are much less likely to bolt than those sown in spring.

Quick-growing Oriental leaves that tolerate cold and are rarely troubled by pests in autumn. Excellent for cut-and-come-again harvesting.

Still fast and reliable. Japanese mooli-type radishes sown now make large, mild roots for autumn. French breakfast types are still useful for salads.

Sow for small autumn roots. August-sown turnips are sweet and quick — harvest at golf ball size.

Late-summer sowings of spinach establish well and crop through autumn. Choose a bolt-resistant variety. Will also overwinter in a sheltered spot.

Some growers plant garlic as early as late August, particularly in northern areas where soil cools sooner. Most varieties prefer planting from mid-October.

Sow Japanese overwintering onion sets or seed now for a harvest next June — weeks earlier than spring-planted onions.

The main harvest season begins properly in August. Pick when fully coloured. Remove any with signs of blight immediately.

Still picking daily. Any that escaped and became marrows should be removed to keep the plant producing.

Pick every few days without fail — pods left too long become stringy and stop the plant setting new flowers.

Check by peeling back a leaf and pressing a kernel — it should release milky juice. Clear juice means too early; doughy paste means too late.

Once the foliage topples and begins to dry, lift and lay on the surface to cure in the sun for a week before storing.

Cut down the tops two weeks before lifting to help skins set. Lift on a dry day and leave on the surface to dry before storing.

Pull as needed. Later in the month, lift the first of the maincrop and store in boxes of barely damp sand.

Harvest regularly before roots become woody. Twist off the tops rather than cutting to prevent bleeding.

Pick frequently — like courgettes, cucumbers left on the plant signal it to slow down production.

Not quite ready yet, but watch for the stem beginning to crack and cork. They need longer but should be coming in September.

August is early enough to order garlic, overwintering onion sets, and spring-flowering bulbs before stocks run out. Note what beds will be empty by October.

High-potash liquid feed every 7–10 days throughout August. Remove any leaves showing yellow patches or brown spots promptly.

Continue pinching out sideshoots on cordon varieties weekly. In late August, pinch out the growing tip two leaves above the top truss to direct energy into ripening.

August heat means inconsistent watering is the most common cause of problems — split tomatoes, bitter cucumbers, bolting lettuce. A regular schedule beats occasional drenching.

Onions lifted in August need at least a week in sun and air before storing. A greenhouse bench or net hung in a shed both work well. Don't store any with soft necks.

Finished pea plants, bolted lettuce, and spent broad beans should come out as soon as they are done. This frees up space and reduces disease and pest habitat.

Cabbage white butterfly is at its peak through August. Check plants for eggs weekly and net if not already done. Caterpillar damage in August can devastate autumn and winter brassicas.

Late blight spreads fastest in warm, humid August weather. Walk the plot after rain and check tomato and potato foliage. Early removal limits spread.

August is the best time to save seed from tomatoes, beans, courgettes, and peas. Choose the best specimens from the healthiest plants.

Grass and weeds around the plot boundaries grow fast in August heat. Keeping these cut reduces slug habitat and makes the plot easier to manage.