Summer marches on and soon autumn will begin to show her hand with shorter days and chilly mornings of ‘mists and mellow fruitfulness’. Cooler temperatures are a sign for most plants to cease growing and begin to close down for winter. This act culminates in the stunning display of autumn leaf colours before these fall to reveal bare skeletons of trees and shrubs, allowing evergreens to come to the fore, standing like sentries in the winter garden.
At this time of the year, late flowering perennials blaze through borders on a mission to give us a show to remember. Pushed into the background are the pastel colours – the silvers, pale pinks, mauves and whites of the midsummer borders. These are replaced by golden yellows, mahogany reds, orange, carmine and cyclamen shades which belong to the many varieties of autumn daisies.
Teamed with ornamental grasses such as Molinia and Miscanthus, these daisies add a natural, ‘prairie’ feel to the garden. The brilliant golden-yellow Rudbeckia is one of the best, lighting up our borders for weeks from late July until well into September. When the glowing petals finally fall, the brown cone-like centres are revealed and add another dimension to this area.
Heleniums are another autumn wonder; their stiff, upright stems topped with flowers in rich orange, red and yellow shades. ‘Moerheim Beauty’ is one of my favourites with dark mahogany coloured blooms and ‘Wyndley’ is a beautiful rusty orange. Slow to make big crowns, they are best planted in a drift of three or five plants depending on the size of your border and look stunning backed by the arching mounds of dwarf Miscanthus whose ‘feather duster’ flowers take over once the Helenium flowers turn to seed heads.
The real stars of the show in our autumn garden have to be Asters. Just asking to be picked for a vase where they will last for ages in water, it’s possible to have varieties of these cottage garden favourites in flower in the garden from August until October. Some of the taller varieties of Michaelmas Daisies have been handed from neighbour to neighbour over the garden fence for hundreds of years and these good tempered plants are very easy to increase by dividing the crowns after flowering or in early spring. ‘Winston S Churchill’ is a beautiful older variety with ruffled flowers of deep magenta-red surrounding a bright yellow centre. ‘Marie Ballard’ is one of the earliest to flower with double flowers of mauve-blue on branching stems. When in full flower, many Asters carry so many blooms that they completely cover the leaves – a magnificent site in autumn borders. There are colours to suit all tastes from clear blues and misty pale pinks to vibrant carmine and cerise varieties. Some plants make low mounds – ideal for the front of a border, and others will grow tall to fill a space at the back. Their sturdy stems mean that once they have acclimatised to your garden, Asters rarely need supporting like some tall perennials.
A late treat for gardeners, I find these perennials easy to look after. They prefer a well cultivated, moist soil which does not dry out in summer, so we give a good mulch of garden compost around the crowns in spring or in autumn after they have flowered. Taller varieties are given the ‘Chelsea Chop’ in late May by removing two thirds of the growth. This will encourage a shorter, sturdier plant with more side shoots and so more flowers at the end of the summer. With little care, these lovely plants will continue to brighten our garden for many years to come.