What Can You Plant in Pots in August

August isn't the end

It's easy to look at a patio full of finished lettuce and bolted basil in early August and assume the growing season is winding down. For containers specifically, it isn't, not yet. There's a genuine, useful window of things that sow well this month and give you something to actually eat before autumn properly sets in, rather than a token last gasp before everything goes quiet.

The key distinction worth making before anything else: sowing seed, planting young plants, and buying an already-established plant are three different things in August, and they carry very different odds of success. A packet of seed sown now for a fast, cool-season crop like radish or rocket has plenty of time to mature. The same packet of tomato or courgette seed, sown from scratch this month, technically might germinate, but it's extremely unlikely to produce a worthwhile crop before the weather turns against it. If you want a summer crop like that still going, buying an already-growing young plant, rather than starting from seed, is the only realistic route in August.

Most of what's worth sowing this month goes in direct, straight into the final container, rather than started elsewhere and transplanted later. Fast, shallow-rooted salad crops generally dislike root disturbance and establish faster when they're not moved partway through, so sowing thinly into the pot they'll actually grow in, then thinning if needed, is the simpler and more reliable approach for almost everything on this list. If you're new to this, our guide to container growing fundamentals covers pot depth, drainage and compost choice in more detail.

Radishes

Genuinely one of the best August sowings for a container, thanks to how fast they turn around. Sow directly into a pot at least 15-20cm deep, thinly, about 2-3cm apart, and thin seedlings if they come up crowded. Radishes are ready to pull in as little as four to six weeks, which in August means a proper harvest well before the weather turns.

Rocket

A reliable, repeat-harvest August crop. Sow thinly across the surface of a container or window box, and start picking outer leaves once they're a decent size, leaving the centre to keep producing. Rocket sown later in summer, rather than at the height of it, is genuinely less prone to the rapid bolting that a June sowing often suffers in strong heat and long daylight, so August timing works in your favour here rather than against it. Our piece on why lettuce, spinach and coriander keep bolting explains what's actually going on there.

Lettuce

Still viable in August, with one caveat worth knowing: keep August-sown lettuce out of intense direct sun, since strong late-summer sun can still stress young seedlings even as overall day length shortens. A spot with some afternoon shade, or a position that gets morning sun rather than a full blast all day, suits an August sowing better than the brightest spot on the patio.

Spring onions

Sow thinly into a decent-depth pot. They take up very little space for what they give back, and an August sowing gives you a crop through into autumn.

Lamb's lettuce

Worth including specifically because it moves an August sowing beyond "one last summer crop" into genuinely useful autumn and winter food. Lamb's lettuce (also sold as corn salad) is properly cold-tolerant and can be picked well into the colder months, making it one of the few things worth sowing now specifically for later, rather than for right now.

Mizuna, mibuna and mustard leaves

These oriental leaves are excellent small-space August crops precisely because you're growing leaves, not waiting on a large mature plant. All three germinate quickly, tolerate a container well, and can be harvested as cut-and-come-again, giving repeated pickings from a single sowing rather than one single harvest.

What about spinach?

Spinach is a genuine "it depends" rather than a blanket yes or no for August. The right approach is choosing a variety bred for the timing rather than assuming any spinach seed works the same in August as it would in spring. Look specifically for a variety described as suitable for late-summer or autumn sowing, since spring-bred varieties are more prone to bolting if sown now in residual summer warmth, while an autumn-appropriate variety handles an August start considerably better.

What isn't worth starting in August

This is the part a lot of "what to sow in August" content glosses over, and it's genuinely useful to say plainly. Courgettes, tomatoes, French and runner beans and similar summer-fruiting crops are not a good August seed-sowing choice. They might germinate, technically, but there simply isn't enough remaining warm, bright growing season left for them to reach a worthwhile harvest from seed at this point. If you want to fill a gap with one of these specifically, buy an already-growing young plant from a garden centre rather than starting from seed, though even then, expect a modest crop rather than a full summer's worth.

Reusing your summer pots

Most August sowings happen in a pot that's just finished cropping something else, so it's worth treating this as a proper reset rather than sowing straight into tired compost. Clear out any dead or spent plants completely, roots and all. Look at the compost itself: if it's compacted, depleted, or been growing something all summer, refresh it, either topping up with fresh compost mixed through the old, or replacing it entirely for a heavier feeder that's just finished a demanding crop. Sowing directly into exhausted compost is one of the easiest ways to undermine an otherwise good August sowing before it's even started.

Where to put an August container

Position matters slightly differently in August than in high summer. Late-summer sun is still strong enough to stress young, shallow-rooted seedlings, particularly in the middle of the day, so a spot with some protection from the harshest afternoon sun suits most of the crops above better than the brightest possible position. A windowsill, balcony rail or patio corner that gets good morning or evening light, without being baked at midday, is close to ideal for this round of sowings.

Watering new August sowings

This matters more than people expect, since it's easy to assume watering pressure eases off once the peak of summer has passed. It doesn't, not immediately, and small pots holding fresh seed or young seedlings are especially vulnerable. In genuinely hot conditions, containers may need checking daily, sometimes twice a day, though the right habit is checking the compost properly rather than watering to a fixed schedule regardless of whether it's actually needed. For more on this, see our guide to watering plants properly, which covers the finger-test habit that makes this straightforward rather than guesswork.

Quick reference

Crop	Container depth	Light	Approx. harvest	Difficulty
Radishes	15-20cm	Sun or light shade	4-6 weeks	Very easy
Rocket	15cm+	Sun or light shade	4-6 weeks	Very easy
Lettuce	15-20cm	Avoid intense midday sun	6-8 weeks	Easy
Spring onions	20cm+	Sun or light shade	8-10 weeks	Easy
Lamb's lettuce	15cm+	Sun or light shade	8-10 weeks, pick into winter	Easy
Mizuna, mibuna, mustard leaves	15cm+	Sun or light shade	4-6 weeks	Very easy

If you missed last month's window, the July sowing list covers what was still going in then — a fair amount of it overlaps.

If you're in a tropical or warm climate… your "August" isn't the UK's. Treat this as a seasonal template rather than a literal calendar: fast salad and leaf crops go in when the soil's warm and the days are shortening for your own hemisphere, and anything freshly sown needs the same close attention to moisture wherever you're growing it.