What to Plant in August in the UK

August is not too late to plant in the UK. It is a changeover month between summer harvests and autumn crops. Quick salads can still give useful leaves. Spring cabbage and suitable onion varieties can begin a much longer journey.

The right choice depends on location, weather and the variety. A coastal garden in southern England has a different window from an exposed Scottish plot. Treat the seed packet as the final instruction and use this guide to make a sensible shortlist.

What can you sow in August?

Good August choices include leafy salads, pak choi, turnips, spring onions and spinach. You can also sow spring cabbage and onions bred for overwintering. The RHS August growing guide includes these as useful late-season jobs.

Choose crops for their next stage, not simply because seed remains in the packet. Some will be ready in autumn. Others establish before winter and resume growth later.

Use the UK vegetable planting calendar to see how August fits the wider year. Our seed sowing calendar is also useful when planning several months at once.

Quick salads

Rocket, mustard leaves and other cut-and-come-again salads suit small, repeated sowings. This avoids one large crop becoming ready at once. It also reduces the loss if heat prevents one batch from germinating.

Sow into damp soil and keep it evenly moist. A temporary shade cloth can help during hot afternoons. Containers are useful because they can be moved away from fierce sun.

Do not assume every lettuce suits late sowing. Choose a variety labelled for late summer, autumn or winter use. Follow the packet for spacing and protection.

Pak choi and other oriental leaves

Pak choi often performs better as the hottest part of summer passes. Long days, dry soil and heat can encourage premature flowering. Later sowing can therefore suit the crop, although warm spells still need careful watering.

The RHS pak choi guide recommends small batches for a steady supply. Leaves can be taken young, or plants can mature if conditions remain suitable.

Sow thinly and protect seedlings from slugs, snails and flea beetle. Netting can deter pigeons, but it must be secured without trapping wildlife. For more detail, read our guide to growing pak choi and Asian greens.

Spinach and chard

Spinach dislikes prolonged heat and dry soil. A late summer sowing may establish as temperatures moderate. Choose a suitable variety and keep the seedbed damp.

Chard is slower but can remain productive into cooler weather. In colder or exposed gardens, young plants may need protection. Our spinach growing guide covers sowing, thinning and common problems.

Turnips and radishes

Fast roots can use gaps left by cleared potatoes, peas or early salads. Turnips provide both roots and edible leaves. Radishes are quick, but they become woody when growth stops through drought.

Prepare a fine seedbed and remove large stones. Water before sowing if the ground is dry. Thin seedlings according to the packet rather than leaving a crowded row.

Spring onions

Choose spring onions sold for late or overwintering sowing. They need free-draining ground because cold, wet soil is more damaging than low temperature alone.

Sow a short row rather than the whole packet. A second small sowing gives some insurance against poor weather. See our spring onion guide for container and open-ground options.

Crops to start now for later harvests

August sowing is not only about quick results. Spring cabbage and overwintering onions establish while soil remains warm. They then grow slowly or pause during winter.

Spring cabbage

Sow spring cabbage in a nursery row or modules, following the packet. Young plants can move to their final spacing later. Firm soil helps brassicas remain stable through autumn wind.

Protect seedlings from cabbage root fly, caterpillars, pigeons and slugs. Fine mesh or netting must be supported above the leaves. Check it regularly for holes and trapped animals.

Do not sow a spring cabbage variety at random. Its timing and hardiness matter. Gardeners in colder regions may need an earlier start or stronger protection.

Overwintering onions

Some onion varieties are sold specifically for late summer sowing. They establish before winter and continue in spring. Ordinary spring-sown varieties may not behave the same way.

Choose an open, sunny site with drainage. Avoid recently manured ground, which can produce soft growth. Follow the supplier’s timing because August sowing dates differ between varieties and regions.

What can you plant rather than sow?

Container-grown perennials can be planted when soil is moist and workable. Water the pot first, then water the planting hole after firming. Delay the job during drought or a severe heat warning.

Some bulbs sold for autumn flowering also go in during late summer. Check the label carefully, because similarly named bulbs can have different schedules. Order spring-flowering bulbs now, but plant each type at its recommended time.

Avoid buying thirsty plants simply to leave them in small pots. Either plant promptly or place them in a sheltered holding area. Check moisture daily until they reach the border.

How to sow successfully in August

Late summer sowing fails most often because the top layer of soil dries out. Small seeds sit close to that surface. One hot afternoon can interrupt germination.

Use this straightforward method:

1. Clear the previous crop and remove perennial weeds.
2. Add mature compost if the soil needs organic matter.
3. Rake a fine, level surface without crushing wet soil.
4. Water the drill before sowing when conditions are dry.
5. Sow at the packet’s stated depth and spacing.
6. Label the row with crop, variety and date.
7. Keep the soil damp until seedlings establish.
8. Thin promptly so remaining plants have space.

Water gently to avoid washing seed into clumps. A watering can with a fine rose is easier to control. Morning watering gives foliage time to dry before night.

Adjust for where you garden

Southern and sheltered gardens often have a longer autumn. Northern, inland and exposed sites can cool much sooner. Altitude, wind and waterlogged soil shorten the practical window too.

If the packet gives a broad range, use local conditions to choose within it. A cloche or unheated greenhouse can extend some leafy crops. It cannot turn an unsuitable variety into a hardy one.

Propagate strawberry runners

Healthy strawberry plants often make runners in summer. Peg a young plantlet into a small pot of compost while it remains attached. A bent wire or hairpin holds it steady.

Keep the pot moist while roots form. Cut the connecting runner only after the plantlet resists a gentle tug. Discard weak or diseased growth rather than multiplying a problem.

Our strawberry runner guide explains renewal and aftercare in more detail.

What to harvest in August

August is a busy harvesting month, but readiness matters more than a calendar. Depending on the garden, you may have courgettes, beans, tomatoes, potatoes, beetroot, onions and soft fruit.

Pick courgettes while the skins are tender. Harvest beans regularly before pods become coarse. Tomatoes should show the colour expected for their variety. Check potatoes carefully and stop if the crop shows signs of disease.

Never eat an unfamiliar plant because it resembles a crop. Correct identification comes first. Keep ornamental bulbs, treated seed and plant chemicals away from food storage areas.

Deal with gluts while produce is fresh. Freeze, preserve or share only sound crops. Compost diseased material only when your system reaches conditions suitable for the problem.

What not to start in August

Warm-season crops such as outdoor tomatoes, courgettes and runner beans usually need a long season. Starting them from seed in August is unlikely to give a useful outdoor crop in most UK gardens.

That does not mean every garden task should stop. Use cleared space for suitable salads or green manure. Prepare beds for autumn planting. Order garlic and bulbs from a reputable supplier.

Avoid forcing a sowing into very dry soil. Waiting for cooler, damper conditions can be more sensible. The seed packet and short-range forecast should decide the final date.

A practical August checklist

• Choose varieties specifically offered for late summer or overwintering.
• Make small sowings of salads instead of one large row.
• Keep seedbeds moist during germination.
• Protect brassicas without leaving loose netting.
• Root healthy strawberry runners in pots.
• Harvest little and often where crops keep producing.
• Remove diseased plants and clean reusable supports.
• Note what worked for next year’s plan.

The useful August jobs are modest and well timed. A few short rows can supply autumn leaves. Carefully chosen cabbage and onion varieties can carry the plot into another season.

Browse more UK growing guides or plan the next stage with what to plant in September.

Frequently asked questions

What vegetables can I plant in August in the UK?

Sow quick salads, pak choi, turnips, spring onions and suitable spring cabbage. Check each packet because timing varies by variety and region.

Is August too late to sow vegetables?

No, several fast and overwintering crops can still be sown. Prioritise short harvest times and varieties sold for late sowing.

Can I sow lettuce in August?

Yes, choose lettuce labelled for late summer or winter growing. Sow small batches and shade the seedbed during very hot weather.

What flowers can I plant in August?

Plant container-grown perennials when soil is moist and suitable autumn-flowering bulbs. Delay planting during drought or persistent extreme heat.

What needs harvesting in August?

Many gardens have beans, courgettes, tomatoes, potatoes and soft fruit ready. Pick only crops that are ripe and identify unfamiliar produce first.