What flowers to plant in September – 10 blooms you can add to your garden now for beautiful displays next year

The growing season might be winding down this month, but there's still lots to do in the garden. It's also a great time to plan for next year's garden – so if you're wondering what flowers to plant in September, you'll be pleased to know there's plenty of choice.

The list of jobs to do in the garden in September is surprisingly long, and so is the list of flowers you can plant this month. Whether you're wondering what to plant in pots in September or working on your flower bed ideas, there's lots of room to get creative with colour and texture. And if you've been wondering when to plant bulbs for spring, September is the prime time.

So, if you're looking for some planting inspiration, we've rounded up a list of what flowers to plant in September.

The best flowers to plant in September 

Sowing certain annuals, biennials and perennials now can reward you with a flush of blooms next spring.

'September is the perfect time to plant flowers,' says garden designer Harriet Worsley. 'The ground is still warm, and the plants will have the full spring period of the following year to begin to flourish and grow in time for spring and summer flowering.'

If you're wondering what flowers to plant in September exactly, here are our top picks.

1. Foxgloves

Foxgloves were big at this year's RHS Chelsea Flower Show, and it's easy to see why: the bell-shaped blooms make beautiful features of garden borders and cottage garden ideas. Plus, learning how to grow foxgloves is relatively easy, and September is a good time to get them in the ground.

'If you want your foxgloves to flower next summer, buy them now as small plants when they have already formed a rosette of leaves, ready for flowering next year,' Harriet advises.

Foxgloves are prolific self-seeders, meaning they'll do the sowing for you in future years. 'If you plant them three years in a row, you should get a great rotation of flowers that then seed, and repeat,' says Harriet.

Where to buy foxgloves:

• Crocus: Go for classic 'Dalmatian White' foxglove plants.
• Sarah Raven: Choose from a stunning selection of foxglove plants.

2. Asters

Asters are another popular choice for September planting. The vibrant flowers are best planted in the spring or the autumn, while the soil is still relatively warm. However, they're pretty flexible when it comes to planting – particularly container-grown varieties.

'Pot-grown asters provide a superb burst of colour at this time of year and can be planted at any time as long as the ground is not frozen or waterlogged,' says Morris Hankinson, managing director of Hopes Grove Nurseries.

Where to buy asters:

• J. Parker's: Choose from a wide range of aster plants for stunning displays.
• Suttons: Grow plants from scratch with these aster seeds.

3. Poppies

Timings around when to plant poppy seeds vary, but they're on our list of flowers to plant in September if you want to be rewarded with beautiful blooms next spring.

'Seeds can be sown all the way through to the end of October, directly in the garden or in containers,' advises Morris. 'They only need to be scattered on the surface of the soil and will flower the following summer.'

Where to buy poppy seeds:

• Thompson & Morgan: Over 30 poppy seed varieties to choose from.
• Sarah Raven: Stock your seed tin with these poppy seeds.

4. Pansies

If you’re a sucker for instant gratification and don’t want to wait until spring to see colourful blooms in your garden, pansies are a great option. If you choose winter varieties and plant them in September, you can guarantee flowers throughout winter and then again in spring. Learning how to care for pansies is straightforward, too.

Don’t worry if you don’t get around to planting your pansies in September, though. These hardy perennials can still be planted in October, but any later than that, and you’ll be in dangerous territory.

Where to buy pansies:

• Suttons: Take your pick from this vibrant range of pansy plants.
• B&Q: More pansy plants to add to your basket.

5. Lupins

We just can’t get enough of lupins at Ideal Home, largely due to the fact that they are perfect for novice gardeners. Not only are they beautiful, but they're fairly easy to grow at home, too.

In fact, the best time to plant lupins from seed is anywhere between February and September. You’ll need to do this in a seed tray for the best chance of success, but that leeway in time is perfect for those looking to add some last-minute colour to their garden. And once you have established lupin plants, you can learn how to propagate lupins at home.

Where to buy lupins:

• Gardening Express: Take your pick from this vibrant selection of lupin plants.
• J. Parker's: More lupin plants to choose from.

6. Alliums

September is the perfect time to prepare your spring garden, and what spring garden would be complete without alliums? These bulbs are readily available from the garden centre and offer the best blooms when they are planted in the autumn, which is the best time to plant alliums.

'I’ve just ordered a mass of alliums to plant as bulbs for next year, but some suppliers also sell them in potted up, so it’s worth checking at garden centres and online now,' says garden designer Harriet. 'If you want a series of flower heads like jugglers’ balls cascading through your beds in purples, mauves and pinks, then alliums are for you.'

Where to buy alliums:

• B&Q: Stock up on allium bulbs.
• Thompson & Morgan: Choose from a wide range of allium bulbs.

7. Crocuses

Offering beautiful shapes and wonderful colour options, crocuses are a welcome addition to any winter garden. And that’s mainly because they thrive in the colder conditions and can often bloom throughout the whole of winter.

It’s best to plant crocus bulbs between September and November, but it’s important to note that their first flower won’t occur until the spring. After that, though, they should flower twice a year – in spring and in winter.

Where to buy crocus bulbs:

• Thompson & Morgan: We love this beautiful range of crocus bulbs.
• J. Parker's: More stunning crocus bulb varieties to choose from.

8. Marigolds

Not to be confused with the very popular washing-up accessory, the English marigold is a beautiful flower that will provide your garden with orange and yellow hues. They’re often used to fill in the gaps in garden borders, or as part of companion planting ideas, and seeds are normally sown in September.

By doing this, you can almost guarantee that your garden will be full of blooming flowers by May next year. Plus, they’re extremely hardy, which means you don’t have to worry about them over the winter months.

Where to buy marigolds:

• Amazon: Order marigold seeds for sowing this month.
• Suttons: Even more marigold seeds to fill your seed tin with.

9. Daffodils

When you think of daffodils, you immediately think of spring. These flowers mark the end of winter and are a welcome addition to any garden.

You might be wondering when to plant daffodil bulbs, though. To guarantee spring blooms, it’s best to plant them in September.

Daffodils can be planted throughout September, and as long as you plant them in full sun or partial shade and in well-draining soil, you should have no problems welcoming these bright blooms next year.

Where to buy daffodil bulbs:

• Crocus: Over 100 different daffodil bulbs to choose from!
• Thompson & Morgan: Enjoy this beautiful range of daffodil bulbs for your spring garden.

10. Hyacinth

With their strong fragrance, bright colours, and ability to thrive in both garden borders and pots, hyacinth is a popular spring flower. Like many other spring bulbs, however, it requires time to establish itself before it starts blooming. And that’s why they're on our list of what flowers to plant in September.

To successfully plant your hyacinth bulbs, place them around 10cm into the ground and around 8cm away from any other bulbs to prevent overcrowding. Then, keep them well-watered.

Where to buy hyacinth bulbs:

• Sarah Raven: Start ordering in your hyacinth bulbs now.
• Suttons: Even more hyacinth bulbs to choose from.

FAQs

What is the best flower to plant in September?

Although it’s possible to plant flowers for autumn flowering in September, this month is best used to start planting your spring bulbs and sowing seeds for next year's blooms.

By planting the likes of hyacinth and daffodils in September, you can allow them to establish their roots and start developing your shoots. This will ultimately give you an impressive garden of blooms in spring.

It's always a good idea to check the seed, bulb or plant packet to make sure the variety you've chosen can be planted in September.

Is September too early to plant bulbs?

If you're wondering when to plant bulbs for spring, September is the prime time for most types.

'Towards the end of September and into October is generally the best time to plant spring flowering bulbs, although tulips should be planted in November and, in mild areas, all the way up to Christmas,' says Morris from Hopes Groves Nurseries. 'While these are the ideal times, don’t panic if you haven’t got your bulbs yet, as they can be planted long into autumn.

'Crocus, daffodils, hyacinths, alliums, lilies and crocosmia can be planted now.'

Now you know what flowers to plant in September, you can start sowing for flourishing spring displays.