8 plants to add to pots in September for instant colour

It’s been a long, hot summer, so no surprise that some areas of the garden are looking less than fabulous. Containers are often one of the first casualties come September with pots drying out and plants dying back.

But it’s not too late to breathe some life back into a tired garden with a splash of late-summer colour - and refreshing faded containers and pots is one of the easiest ways to do it. Simply choose the right combination of plants to add to pots in September and you can enjoy a burst of instant colour that will see your garden all through the autumn months.

‘By September, many summer containers have started to look past their best,’ says Matt J Adams, founder and lead gardener at The Relentless Gardener. ‘But rather than replacing everything, this is a good opportunity to remove plants that have finished, introduce a few fresh performers and give the plants you’re keeping the care they need to continue looking good into autumn.’

1. Chrysanthemums

‘I like to create containers with a mixture of flower colour and foliage, choosing flowering plants that can cope as temperatures begin to fall,’ says Matt. ‘Chrysanthemums are an easy way to make an immediate impact in pots, with compact varieties available in everything from fiery orange and yellow to pink, red and white. Chrysanthemum ‘Conella Orange’, is particularly effective for an autumnal display, and regular deadheading will encourage a longer-lasting show.’

‘Potted chrysanthemums add a lovely splash of colour, including orange, yellow, red, pink and white, and they can be grouped together to create a lively, bold display, says Chris Bonnet, founder of Gardening Express. ‘Place them somewhere sunny with partial shade to help keep the colours vibrant, making sure to keep them moist. If the blooms begin to fade, pinch them off to encourage new growth.’

Where to buy chrysanthemums:

• Thompson & Morgan: Bring autmnal colour to your garden with this fiery Chrysanthemum 'Conella Orange', £19.99.
• B&Q: Enjoy the sunny shades of this easy-to-grow Chrysanthemum Yellow, £10.40.

2. Dahlias

‘September doesn’t have to mean the end of splashes of colour in your garden and it’s actually a great time of year to give tired-looking pots a refresh, especially if they’ve suffered during heatwaves,’ says David Denyer, flower and garden expert at eflorist.

‘Start by removing the plants that are clearly past their best. Deadheading plants like dahlias will encourage the roots to concentrate energy on new growth and flowers, potentially leading to another flush of colour before the season is out. Dahlias in pots are fantastic for providing bold colours later in the season and can continue flowering well into early autumn when conditions are hit and miss.

‘Dahlias are a great choice for adding instant colour to pots throughout September,’ adds Chris. ‘With a wide range of colours, shapes and sizes, choose compact varieties for containers and look for plants already in bud for an immediate display. Plant your dahlias in good quality peat-free compost with good drainage, and position in full sun.’

Where to buy dahlias:

• Sarah Raven: In deepest pink that will add instant impact, try Dahlia 'Molly Raven', from £6.95.
• Gardening Express: Or go for the peachy tones of this Giant Flowered Dahlia - Salmon Runner, £12.99

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3. Sedum

‘Sedum also looks lovely throughout September, making them perfect for pots at this time of year,’ suggests Chris. ‘Planting them in September gives their roots time to establish, while their delicate flowerheads provide a beautiful splash of colour that can last well into autumn.’

‘Sedum is a great low-maintenance container plant that can be particularly useful when you want pots to continue looking interesting as summer draws to a close,’ adds David. ‘It’s foliage actually stores water, making it extremely forgiving during dry periods, and the plant remains attractive even when it isn’t in bloom, making it a useful choice if you want your containers to offer more than flowers alone.’

Where to buy sedum:

• Gardening Express: With large heads of rusty red flowers, try Sedum Herbstfreude - Autumn Joy, £7.99.
• Primrose: Or go for the paler pink tones of this Sedum Matrona, Stonecrop Hylotelephium, £7.99.

4. Pansies and violas

‘In September, you want to be thinking about adding plants that are going to last through the cooler months,’ advises Craig Wilson, co-founder and gardening expert at Gardeners Dream. ‘Bedding plants, like pansies and violas are great choices and are easy to care for. They are hardy plants that can survive tough weather, including frost, and the bright colour options give gardens a lovely boost to see you through the darker months.’

‘Pansies and violas thrive best in positions where they can enjoy around four to six hours of sun a day, but partial shaded spots also work well for them, too,' adds Craig. 'Just remember that if you have your pansies or violas in pots and hanging baskets, they tend to dry out quicker than if they are planted in garden beds, so keep a close check on them. I’d aim to water around once a week if the weather is dry, reducing the frequency once the autumn rain hits.’

Where to buy pansies and violas:

• Gardeners Dream: Enjoy the purple and white tones of these pretty Pansy Ocean Breeze plants, £16.99 for a pack of six.
• J. Parker's: Or go for these sunny orange and purple Viola Sorbet Orange Duet, from £11.99.

5. Cyclamen

‘Cyclamen are a good choice when a container is positioned somewhere that doesn't receive full sun,’ suggests Matt. ‘Hardy varieties such as Cyclamen hederifolium combine delicate flowers with interesting foliage and can bring autumn colour to a darker corner of a patio or entrance.’

‘But choosing the plants is only half the job,’ adds Matt. ‘Containers can dry out surprisingly quickly, even in September, so water containers thoroughly when needed while making sure excess water can drain away. If you're reusing a pot, remove tired plants and dead roots, refresh the surface of the compost and avoid overcrowding the new planting. Giving plants a little more space may mean the container looks less full initially, but they'll have better conditions to establish.’

Where to buy cyclamen:

• Suttons: Bold pink flowers look eye-catching, Cyclamen hederifolium, from £8.99.
• Thompson & Morgan: Or go for the vibrant purple flowers of these Cyclamen coum, from £9.99.

6. Bidens

‘Bidens boast yellow or white daisy-like flowers and will provide plenty of colour throughout September,’ says David. ‘And their shape can add a level of versatility to a display when added to pots and containers.’

‘Bidens are also more drought-tolerant than a lot of bedding plants, coping well with the occasional missed watering, so a great option for gardeners looking for maximum autumnal colour with minimal maintenance involved.’

Where to buy bidens:

• Thompson & Morgan: Add a burst of sunny colour with these Bidens ferulifolia 'Golden Eye' - Seeds, 99p per pack.
• Amazon: Or go for multicoloured flowers with these Mixed Biden seeds, £8.99 per pack.

7. Ornamental cabbage and kale

‘If you want to rely less on flowers, ornamental cabbage and kale can provide plenty of interest for pots through autumn,’ suggests Matt. ‘Their foliage develops stronger shades of green, purple, pink and white as temperatures fall, and they add useful texture when combined with flowering plants.’

‘Feeding is also important if you want flowering plants to keep performing into autumn. Once plants are actively growing, I use Blooms Booster All-Purpose Liquid Plant Feed with seaweed, from £9.50, from The Relentless Gardener, as part of my regular plant-care routine,’ adds Matt. ‘It has a higher potassium content to encourage flower growth rather than excessive foliage, and contains 20% liquid seaweed to support healthy roots and shoots. It only needs applying every three to four weeks, so it’s an easy addition to regular watering.’

Where to buy ornamental cabbage:

• Carbeth Plants: Add drama with these vibrant ornamental cabbages, £11.99.
• B&Q: Or go for this pale toned variety White Ornamental Cabbage 4 Pack, £11.99.

8. Heucheras

‘For something that can provide interest beyond a single season, heucheras are another useful container plant,’ suggests Matt. ‘Their foliage comes in shades ranging from bright lime to deep burgundy and almost black, making them particularly effective for adding contrast to brighter autumn flowers.’

‘But the aim isn't simply to keep a container looking colourful for another few weeks. Good feeding, sensible watering and choosing plants suited to the conditions can help maintain healthier plants and prolong the display as summer gives way to autumn.’

‘September containers don't need to be complicated. Start with a few plants that are already looking good, combine different heights, colours and textures, and then look after them properly. With the right care, a tired summer pot can become one of the most useful features in the garden as the season changes.’

Where to buy heucheras:

• Gardening Express: Mix it up with the combination of colours in these Handsome Heuchera Collection, £24.99.
• Primrose: Or go dark with this dramatic purple Heuchera Wildberry Coral Bells, £12.99.

So, the end of summer doesn't have to mean the end of your container displays, revive pots with a few new plants and they'll see you right through autumn.