Midsummer is a time of plenty in the garden with roses blooming, sweet peas in their prime and borders a riot of colour. But as summer progresses and cottage garden stalwarts begin to fade, there are some fantastic late-flowering plants ready to carry the torch into autumn.
It’s at this time of year that North American perennials and annuals really come into their own. Unlike meadows in the UK which generally peak at midsummer, North American grassland reaches its zenith around late summer or early autumn, making prairie flower displays ideal to keep the colour in the garden going well past the summer equinox. The daisy flowers of echinacea, helenium, aster and rudbeckia are also fabulous sources of nectar for pollinating insects.
Best varieties of rudbeckia
Rudbeckia (commonly known as coneflower or black-eyed Susan) was named after Olof Rudbeck (senior), the Swedish Professor of Medicine and polymath who founded the Uppsala Botanical Garden in 1655.
All rudbeckias prefer an open sunny spot with soil that has been improved with organic matter. They can be planted in spring or autumn, or sown from seed. Charismatic Rudbeckia hirta is a valuable annual to add to container displays and to the late summer border, often flowering up until the first frosts. There are many annual cultivars to suit different colour schemes:
- R. hirta ‘Cherry Brandy’ – rich crimson flowers
- R. x hirta hybrida ‘Cherokee Sunset’ – mahogany, orange and bronze flowers
- R. hirta ‘Chim Chiminee’ – cheerful yellows, oranges and reds
One of the most popular perennial rudbeckia varieties is R. fulgida var. sullivantii ‘Goldsturm’ – a robust and reliable flower that likes to be kept moist in summer. The open yellow petals contrast with the dark central eye, making it a striking bloom, especially when planted in swathes through grasses or with other prairie flowers like echinacea and heleniums.
Sophisticated ‘savannah mixed’
This year I’ve planted Thompson & Morgan’s new and exclusive, half-hardy annual R. ‘Savannah Mixed’ from their own breeding programme. Beautiful colour-changing double flowers with petals in shades of yellow-green, wine-red and burnt orange, ‘Savannah Mixed’ evokes the subtle colours of the grassy African plains and brings real elegance to late summer displays. It looks best planted en masse in containers or borders, where the flowers combine to create a sophisticated scheme.
In my garden, I’m planting R. ‘Savannah Mixed’ with grasses (Briza maxima, Deschampsia cespitosa and Stipa tenuissima) and with other late-bloomers like Helenium ‘Moerheim Beauty’. The muted lime, burgundy and copper tones of the rudbeckia add touches of colour without disturbing the soft mood created by the grass seed heads gently swaying in the breeze. And as the flowers age the colours deepen, providing an effortless transition to autumn in your late summer borders.
Summer flowers can keep your garden looking bright and colourful throughout the season – for more ideas and advice, head to our summer flowers hub page. And if you’re looking for more advice on which ornamental grass you should grow and where, visit our grasses hub.
Nic Wilson is a writer, garden designer and Garden Media Guilds Awards nominee (Best Blog, 2018). She enjoys growing flowers and unusual fruit, vegetables and herbs, and loves to encourage nature into the garden. She also blogs at www.dogwooddays.net