In August, an English raised bed still has room for quick crops: sow radish, lettuce, rocket, spinach, spring onions, baby turnips and pak choi outdoors, and plant out sprouting broccoli for next spring. The RHS adds spring cabbage, oriental leaves and overwintering onions, though it gives its August sowing list for the south of England only.

Illustration of a late-summer raised bed with a freshly sown salad row in front of cropping runner beans and a courgette plant
IllustrationIn August, every gap left by an early crop can take a quick sowing of salads, turnips or pak choi.

August is a month of picking more than sowing. Beans, courgettes, tomatoes and the first maincrop potatoes are coming in, and every space you clear can take a fast salad or a winter crop. Below is what to sow, what to plant, the jobs that matter now and what is your last chance before autumn.

At a glance: what to plant in August

TaskCropsSource
Sow indoors or under coverNothing essential: the RHS August list is all outdoor sowingRHS
Sow outdoorsRadish, summer lettuce, rocket, spinach, spring onions, turnips, pak choi, Chinese cabbage, mizuna, spring cabbage, overwintering onionsRHS (south of England); spinach from Sowstory
Plant outSprouting broccoli raised from a spring sowingSowstory
HarvestRunner and climbing French beans, courgettes, outdoor tomatoes and cucumbers, maincrop potatoes, beetroot, calabrese, summer cabbage, peppers and chilliesSowstory harvest windows

Sow indoors

There is nothing on the RHS August list that needs a windowsill or a heated propagator; everything goes straight into the soil. The indoor work for winter crops happened in spring: Sowstory raises sprouting broccoli, kale and leeks from sowings between March and May.

If the weather is hot, the problem in August is germination, not cold. The RHS notes that lettuce germinates poorly in hot spells and suggests sowing in the evening, watering the drill with cold water and shading the row.

Sow or plant outdoors

Quick salads

Summer lettuce, radish and rocket are the backbone of August sowing. Loose-leaf lettuce is ready to pick in about four to six weeks according to the RHS, once the leaves reach about 10 cm. Sowstory plans rocket for picking roughly four to six weeks after sowing, and reserves about eight weeks of bed space for each batch of radishes. See our guide to growing lettuce for spacing and bolting.

Spinach comes back into Sowstory's plans this month. It is treated as a cool-season crop, sown from March to May and again in August and September, skipping the hottest weeks of summer.

Oriental leaves and turnips

The RHS lists pak choi, Chinese cabbage, mizuna and mibuna for August. Sowstory sows pak choi in succession from May to August and harvests from June to October. Baby turnips sown now give small roots in about six to ten weeks.

Onions for next year

Spring onions can still be sown. The RHS says hardy varieties sown in late summer or early autumn will crop from March. Overwintering onions are on the RHS August list too; the RHS warns that autumn onions can rot in heavy soil that stays waterlogged over winter.

Spring cabbage

The RHS sows spring cabbage in July or August and plants it out in September. Sowstory's cabbage profile is a compact summer cabbage, so spring cabbage is not in its plans yet.

Plant out sprouting broccoli

Sprouting broccoli raised from a spring sowing goes into the bed in July or August. It is a big, long-lived plant: Sowstory places it on the north edge as a tall crop, allows about 60 × 60 cm per plant and reserves the space until the harvest from February to May next year. Gardeners' World says purple sprouting can take down to −12°C. Our broccoli growing guide covers the different types.

Green manure for empty space

If a bed will stand empty, the RHS suggests sowing a green manure such as crimson clover or Italian ryegrass when rain is forecast.

In a Sowstory plan this month

These are the crop profiles Sowstory lets you start in the bed in August, with their windows:

  • Radish (small round spring and summer types): March to August
  • Loose-leaf lettuce and head lettuce: March to August
  • Annual spinach: March to May, then August and September
  • Spring onion: March to August
  • Salad rocket: March to May or August, sown direct
  • Baby turnip: April to August, sown direct
  • Pak choi: May to August, in succession
  • Sprouting broccoli: sown March to May, planted out July to August

Sowstory's windows are England-wide months. They are not adjusted to your postcode, so if you garden in the north or on high ground, judge the conditions on the day.

If you are working out what fits into the gaps left by summer crops, Sowstory will lay out your bed to scale and give you a month-by-month plan, including succession sowings where supported. It is coming soon to the App Store, and your first bed plan is free.

Jobs this month

  • Water regularly and evenly. The RHS links uneven watering in August to blossom end rot on tomatoes and to split roots.
  • Watch for blight. Remove blighted leaves. Blight spreads in warm, wet weather; on potatoes, the RHS advises cutting the stems at soil level once about a quarter of the leaves are affected and lifting the tubers about two weeks later.
  • Lift maincrop potatoes for storage when the leaves yellow: cut off the top growth, wait 10 days, then lift, let the tubers dry for a few hours and store them somewhere dark, cool and frost-free.
  • Check stored onions for neck rot.
  • Keep carrots covered. The second generation of carrot fly lays eggs from August to September.
  • Net brassicas. Cabbage caterpillars are likely from August to September; keep fine netting clear of the leaves.

Last chance

August is the final month in Sowstory's windows to start radish, both kinds of lettuce, spring onions, rocket, baby turnips and pak choi, and to plant sprouting broccoli. Only spinach carries on into September. Carrots and beetroot finished in July, which is why the July sowing guide is the place to look if you missed them.

Autumn frosts arrive at very different times across England. Met Office averages for Shap in upland Cumbria include air frosts in September, while Teignmouth on the Devon coast averages none in October. Our guide to the last frost date explains how to judge the risk where you live.

Next up: in September the RHS sows overwintering spinach, winter lettuce and rocket, and plants overwintering onion sets; see what to sow in September. Garlic follows from October, and our guide on when to plant garlic explains the timing. For the whole year on one page, use the vegetable sowing calendar.

Sources