5 low-maintenance perennials to plant in September for late-season colour – including penstemons

If you thought the arrival of autumn marks the end of all the gardening fun, you’d be mistaken. Rain has returned and temperatures have dropped to much milder levels, but the soil is still warm, making September an ideal time to add fresh plants to your plot.

Perennials are particularly rewarding garden dwellers. They come in all shapes, colours and sizes, come back each season and, those forming clumps, even give you free shoots to replant from time to time.

Whether you’re looking to cover a bare patch in your border, add a show-stopping new flower or are simply introducing lush greenery, there is a perennial for you. Below, we’ve rounded up five popular varieties that couldn’t be simpler to grow.

These tough ground-cover plants have so many favourable properties that some might say no garden is complete without them.

‘Hardy geraniums are a great one to plant in September, as the soil is still warm but the cooler weather means they don’t have to cope with the heat of summer,’ says Jo McGarry, luxury garden design expert at Caragh Nurseries.

‘They’re pretty easy-going and once they’re settled, they’ll come back year after year without needing too much attention. Planting them now gives the roots plenty of time to get settled before winter.’

Heucheras are a popular garden addition because their kaleidoscopic foliage provides colour when flowering plants have faded. ‘Their leaves come in loads of different shades, from deep purple to bright green, so they can keep a border looking interesting,’ says Jo.

‘September is a good time to get them in the ground because the soil is still warm, giving them plenty of time to settle before the colder weather arrives.’

Rudbeckias – also known as black-eyed susans – are a late-season staple, really coming into their own when other flowers fade.

‘Rudbeckias are a good one if you want to keep some colour in the garden into autumn,’ says Jo. ‘Their bright, daisy-like flowers can keep going when plenty of other plants have started to fade.’

‘Planting them in September gives them a chance to get their roots settled before winter, so they’re ready to put on a good show next year.’

‘Salvias are a favourite for sunny spots and September is a good time to plant them,’ says Jo. ‘The soil is still warm at this time of year, but you’re avoiding the really hot, dry conditions of summer. Just make sure they’re planted somewhere with good drainage.’

Once established, they are extremely low maintenance, giving you little blooms through the warmer months.

Rudbeckias aren’t the only good choice for late-season colour. ‘Penstemons are a lovely choice if you want something that will keep flowering late into the year. Their trumpet-shaped flowers add a bit of height to borders and are also great for pollinators,’ says Jo.

‘Planting them in September gives them a few months to settle before winter. I’d just make sure they’re somewhere sheltered and not sitting in soggy soil, as they really don’t like wet feet.’…Read more by Wanda Sachs