After the long, hot summer, when our gardens were quite literally clinging on for dear life, this autumn has been a blessed relief. It has been wonderful to get outside and stuck in again, making a few changes that will hopefully come into their own next year.
September and October, I think, are becoming two of my favourite months in the garden — and I don’t think I am alone in that.
There is something different about the light at this time of year. It becomes golden and warm, with the ferocity of summer taken out of it. Early mornings are misty, and provocative. There is more shadow, more mystery, a sense of romance and nostalgia that I find give this season its charm.
Designing a Garden for an Autumn Peak
Many planting designers deliberately create schemes that reach their peak in late summer and autumn.
Subtropical gardens, for example, often really come into their own later in the season. Nicotianas are still flowering and Tithonia rotundifolia — the wonderfully vibrant Mexican sunflower — can continue producing its vivid orange flowers well into autumn.
Another fabulous plant at this time of year is Heptacodium miconioides, or seven-son flower. Its clusters of beautifully scented white flowers appear from late summer into autumn, followed by colourful red calyces. It is a wonderful specimen shrub or small tree for bringing fragrance and interest into the garden later in the year.
Prairie Planting in Autumn
Prairie-style planting schemes often look at their absolute best at this time of year.
The way the early autumn dew catches the seed heads of grasses and perennials, particularly when the low morning light shines through them, is one of the characters of this type of planting at this time of year that I love.
The famous planting designer Piet Oudolf is perhaps one of the best-known examples of designing with this later-season structure in mind. By autumn, his planting schemes have a rich tapestry of colour, form and texture.
Ornamental grasses are especially valuable now. Miscanthus is in flower, alongside the delicate sprays of Molinia. Calamagrostis takes on beautiful golden tones, while Stipa gigantea holds its tall, airy seed heads above the planting.
Rather than cutting everything back as soon as flowering finishes, leaving some of these structures standing allows the garden to continue evolving long after summer.
Late Flowering Perennials
There are also plenty of perennials keeping the garden going into September and October: Rudbeckia, asters, Gaura, Persicaria, Eupatorium and, of course, the many later-flowering salvias.
Two groups I am particularly interested in at the moment are the later-flowering salvias and the different varieties of asters.
The shrubby salvias have small aromatic leaves and delicate flowers in colours ranging from pale pink and red through to rich purple.
One particularly lovely variety is Salvia ‘Nachtvlinder’, with deep plum-purple flowers that continue for a long period from summer into autumn.
I have seen it planted en masse alongside white and pale pink Gaura. Perhaps it doesn’t immediately sound like an obvious combination, but the softness of the Gaura balances the dark flowers of ‘Nachtvlinder’ beautifully. I thought the effect was incredibly attractive.
Rediscovering Asters
Personally, I haven’t grown a huge number of asters.
When I worked at the nursery, I used to see Aster × frikartii ‘Mönch’ looking slightly straggly in its pot and, if I’m honest, I was never particularly drawn to it.
It is only when you see asters growing naturally through established borders — in gardens such as Beth Chatto’s — that you begin to appreciate how beautiful they can be.
I particularly like the varieties that have a more upright habit, delicate foliage and masses of small, dainty flowers.
Some of the plants traditionally known as asters have now been reclassified botanically. In particular, the popular New York and New England asters are now placed within the genus Symphyotrichum: Symphyotrichum novi-belgii and Symphyotrichum novae-angliae. They are still commonly referred to as asters or Michaelmas daisies, which is perhaps considerably easier to remember.
Many originate from North America and, given the right conditions, they are fantastic additions to a mixed border or prairie-style planting scheme, providing valuable colour late into the season.
I have a feeling that Symphyotrichum ‘Prairie Purple’ may be finding its way into one of my planting schemes very soon.
And perhaps that is one of the best things about autumn gardening. Rather than feeling like the end of the season, September and October can be some of the richest months of the gardening year, and most interesting for Cornwall Garden Design. There is still lots of see and enjoy, while we plan and feel inspired for the future.