Gardening tips for extending the season

Late summer colour in the cottage garden

With fine and warm weather, we still like to sit out in the garden in September. Here are some top tips from head gardeners across the region to help you create lasting garden colour that continues to provide pleasure through September into autumn.

‘It’s important to sustain interest in the garden,’ says Ham House head gardener Rosie Fyles. ‘We’re taught as gardeners that each plant has to justify its place in the garden. If it only has a one-off splash, then it has to be really special. However, a plant that can sustain interest and colour throughout the seasons is a winner.’

Jonny Norton, head gardener at Mottisfont in Hampshire

‘I recommend planting out annual cosmos of various heights and colours amongst your roses. A packet of seeds sown in late spring goes a long way to maintaining colour and structure through the late summer and early autumn. 

‘My favourite is a pure white variety called ‘Purity’. It can get tall if left unattended, so it will benefit from some support or sensitive pruning.’

Cosmos, just one of the flowers in our walled garde
A delicate white Cosmos in the White Border
Cosmos, just one of the flowers in our walled garde

Anthony Mason, head gardener at Cliveden in Buckinghamshire

‘If you get chance to buy only one plant and can dip a little further into your pocket, buy a Japanese Maple tree. There are varieties that will grow to medium-sized trees for large gardens and small varieties that you can put in pots for smaller gardens or balconies. They have intensely coloured and beautifully shaped foliage and will provide years of enjoyment.’

Firey red
Japanese maple tree leaves changing colour
Firey red

Jamie Harris, head gardener at Polesden Lacey in Surrey

‘One of the coneflowers will do you proud at this time of year. This could be echinacea, helenium, rudbeckia or the humble sunflower. They’re all perfect for extending the season and are also incredibly cheap and easy to grow from seed. 

‘However, my personal favourite September plant is the Salvia. There are so many beautiful colours and forms to choose from, making them versatile for any planting scheme.’

Rudbeckia flowering in September
Rudbeckia flower in September, yellow petals with blue disc
Rudbeckia flowering in September

Troy Scott Smith, head gardener at Sissinghurst in Kent

‘I suggest a second or third sowing of plants like cosmos and ammi – things that you’d plant out in May. By late season, they’ll have petered out, but if you sow another batch when you plant out the first, they’ll be ready to plant out in August, giving you great colour throughout September.

‘Grasses and anenomes are also useful autumn plants because they don’t need much effort. It also doesn’t look as if you’re trying too hard. There’s a slowness and a shift in gear towards autumn and for me it's the little details - flowers, yes, but also leaf form and seed structure that give a softness that takes us through to autumn.’

For more gardening tips, just speak to any of our gardeners next time you visit, they're always happy to chat.