Despite fading light and a weakening sun, there's no shortage of colour at this time of year
I find autumn a sad season, as the warmth of summer leaks away, and colder, darker hours creep in on us. The garden is changing fast, faster than at other times of the year. Or is it just that I'm more attuned to the daily differences, because I'm regretting the loss of light, heat and life?
But enough of this sorry stuff. All is not doom in the encroaching gloom. There are exhilarating things happening too. Some plants - asters and the later ornamental grasses, for instance - have just recently started to flower, and will go on into next month, and further, depending on frost and rain. The big fleshy sedums, such as 'Herbstfreude' (also known as 'Autumn Joy'), S. spectabile, S. telephium and their many cultivars, are flushing pink across their flat plates of blossom - inviting bees and butterflies to sup from their nectaries.
It's true, there is a lot less light now, but it is golden and gorgeous, especially at either end of the shortening day. It suits the more colour-saturated flowers of the season: the sharp and dusty pinks of sedum, echinacea, eupatorium, and the Japanese anemone 'Prinz Heinrich'; and the purples and wines of the asters, persicarias, verbenas and sages. These colours can sometimes be overly glaring when blasted by the high sun of midsummer, but they come into their own now, in the more mellow and lower-angled light.
The daisy family (Asteraceae) almost owns this latter end of the season, as so many of its members are late bloomers, including echinacea, helenium, helianthus and rudbeckia. The tall purple Joe Pye weed (Eupatorium purpureum) and the yellow-fingered goldenrod are also daisies - although they do not have the characteristic frills of ray florets that are borne by most of the clan. All the above originated in the North American prairies, and are perfect plants for naturalistic schemes - if you have the space.
In her recently-published (and excellent) Late Summer Flowers, Marina Christopher explains why some plants produce their blooms later in the year. Prairie species, for instance, are subject to lots of competition from nearby plants, so they take longer to build up the energy required for flowering.
Grasses, of course, are the stars of the autumn border. Many of the Miscanthus sinensis cultivars are only now thrusting their feathery plumes into the open. Other late flowerers include switch grasses (Panicum) and fountain grasses (Pennisetum). There are still others that have been in flower for months, but their long-lasting seed heads remain an important part of the garden picture. Among these so-called cool-season kinds (which start growing in autumn and flower in spring or summer) are the giant oats (Stipa gigantea), the moor grasses (Molinia) and Calamagrostis 'Karl Foerster'.
With their swaying wands of seed, the taller grasses add movement to the garden in a way that few other plants can. They are also magical catchers of the autumn sun's low rays, glowing as if illuminated from within. So, if your garden is large enough that you have a choice of where to place a border of grasses and other late season plants, pick a spot where they will be lit from behind, or from the side.
Late-flowering shrubs also help to light up the autumn garden: abelia, fuchsia and hebe, just to mention three. One of my favourites - and small enough to grow among perennials - is the Russian sage, Perovskia atriplicifolia 'Blue Spire'. It resembles an outsized lavender, with hazy kernels of flower carried on stiff grey stems. Like lavender, it's not terribly long-lived, but you can propagate it from softwood cuttings in early summer.
Finally, there are plenty of bulbs, corms and rhizomes that erupt from the ground as the days and nights get chillier. Nerine bowdenii, with its spidery, candy-pink flowers, and Schizostylis coccinea (with pink, red, peach and white varieties), both from South Africa, are classic autumn bloomers, often seen in old gardens. So also is cyclamen, in flower for the past month. It is a beauteous sight under trees. If left undisturbed, plants can spread for many metres, their upturned petals like flotillas of tiny mauve and white sailboats, skimming hopefully through the fallen autumn leaves.
Further reading: Late Summer Flowers by Marina Christopher (Frances Lincoln, £25)
The Royal Horticultural Society has published comprehensive bulletins on the results of various plant trials. Among the late bloomers covered are cannas, hardy fuchsias, miscanthus and perennial yellow daisies. They may be downloaded from: www.rhs.org.uk/seedlist/trials_bulletins.asp .