8 Summer Plants You Can Still Plant In August

August gets a bad reputation for being too late. The bedding displays are looking a bit scrappy, there's half the stock on the "reduced" trolley at garden centres, and a general feeling that the good stuff is behind you. But that's not quite right.

The soil in August is warm, often warmer than it was back in May when everyone's rushing to plant. That warmth is really good for root development. You've also usually got at least six to eight weeks before the first serious cold snap, which gives new plants a decent run.

The key is knowing what to go for. Some plants won't thank you for a late start, but the ones on this list will do just fine.

1. Dahlias (from tubers or pot-grown plants)

If you can find pot-grown dahlias still on sale in August, buy them. They'll flower almost immediately and keep going until the first frost, which across the UK falls anywhere from late October in the far north to well into November or later further south.

You won't get the full season out of them, but you'll get six to eight weeks of decent colour with very little effort. Water them in well, give them a stake if they're a taller variety, and deadhead regularly to keep them producing flowers.

2. Rudbeckia

Rudbeckia, sometimes called black-eyed Susan, is one of the most reliable late-summer plants you can buy.

It flowers in shades of yellow and orange, the petals angling back from a dark central cone, and it doesn't mind being planted late. Pop it in a sunny spot, water it for the first week or two, and it'll largely look after itself.

It's a good one for filling gaps left by earlier plants that have finished.

3. Cosmos

Cosmos is usually started from seed in spring, but you can still buy pot-grown cosmos in August at most garden centres and it'll give you flowers well into September.

It's tall and feathery, works well at the back of a border, and comes in pinks, whites, and rich burgundy and red. Don't bother planting it from seed now as it won't have time to get going, but a good-sized pot-grown plant put in now will flower for several more weeks.

4. Verbena bonariensis

This is a plant that rewards you even when it's not in full flower, because it adds structure and height to a border without taking up much space.

The flowers are small purple clusters on tall wiry stems, and they're genuinely excellent for pollinators. Planted in August, it'll flower through to October. It also self-seeds reliably, so once you've got it in your garden, you tend to find it coming back year after year without you doing much about it.

5. Salvias

Annual salvias, particularly varieties like Salvia splendens, are still worth planting in August. They're often available cheaply at this time of year because garden centres are trying to shift stock, so it can actually be a good time to pick them up.

They won't last as long as they would have if you'd planted them in June, but they'll still give you four to six weeks of colour. Perennial salvias are even better planted in August as the warm soil helps them establish before winter, and they'll come back bigger next year.

6. Busy Lizzies (Impatiens)

There's a received wisdom that busy lizzies are a bit old-fashioned and nobody plants them any more, but that's not really true.

They're still one of the best plants for a shady spot in August because almost nothing else flowers reliably in deep shade. The newer varieties, particularly the SunPatiens types, are also much more resistant to the downy mildew that devastated Impatiens walleriana plants back around 2011 and 2012.

If you've got a dark corner that needs covering, they're still one of the most practical options going.

7. Nemesia

Nemesia is a compact, low-growing annual that produces masses of small flowers in mixed colours. It does best in cooler conditions, which is actually one reason late summer suits it reasonably well.

Earlier in summer it can struggle in a prolonged hot spell, but planted in August it'll have slightly cooler evenings to deal with, which it prefers. Keep it watered and it'll flower right through September. It works particularly well in pots and window boxes where you need something tidy and colourful without much maintenance.

8. Ornamental cabbages and kale

This might seem like a strange one to put on a summer planting list, but ornamental cabbages and kales planted in August will establish through September and then come into their own in October.

They're not a summer plant in the traditional sense, but they're one of the best things you can do in August to make sure your garden or patio containers look good through the autumn. The colouring on the leaves, which ranges from deep purple to pale pink and white, actually intensifies as temperatures drop.

They're also much cheaper than most flowering bedding plants at this time of year.

A few general points for August planting

Water is the main thing to think about right now. August can be genuinely dry, and a new plant that hasn't established any root system yet will struggle if you don't keep on top of it.

For the first two weeks after planting, check the soil every day, and if it's dry an inch down, water it.

A liquid feed every couple of weeks from a general-purpose fertiliser will help too.

Don't skip the deadheading either. With only a limited number of weeks left in the season, you want every plant to keep producing flowers rather than putting energy into setting seed. Five minutes with a pair of scissors every few days makes a noticeable difference to how long things keep flowering.

One other thing worth knowing: August is actually a good month to buy plants at a discount. Garden centres reduce a lot of stock at this time of year.

The plants are often perfectly healthy, just pot-bound or slightly root-heavy, and they'll be fine once they're in the ground with a bit of room. It's worth having a look at the sale section before you pay full price for anything.