Duilleoga ar snámh,
Donn, geal is rua,
Ar abhainn na Life,
Ag seoladh le sruth . . .
Duilleoga ar an Life, Séamus Ó Néill's wistful poem, which featured in the Culture Night pop-up garden that I made for Foras na Gaeilge's headquarters last month, is a gentle ode to the colours of autumn. Glowing red. Ember-orange. Bright butter-yellow. A river of floating leaves, as Ó Néill describes it, that carries its richly colourful beauty through our fields, woodlands and busy city roads at this time of year.
As gardeners, it’s sometimes easy for us to take that extravagant beauty for granted. We rarely plan for it in the way that we would with the spring or summer garden. And yet there are many plants – not just trees and shrubs, but also perennials and grasses suitable for smaller gardens – whose vivid autumnal livery can be cleverly used to gild the garden at this time of year.
Take the humble hosta or plantain lily, the shade-loving perennial prized by gardeners for its elegant, architectural leaves. It is ideally suited to container growing because this protects the foliage from slug damage. Many varieties, including Hosta ‘Frances Williams’ and Hosta sieboldiana var elegans, also take on deliciously buttery shades as summer fades.
Colourful pairings
For a really vivid display of autumnal colour, pair these hostas with other shade-loving perennial foliage plants with equally dazzling seasonal foliage. For instance, there is the handsome Royal fern, Osmunda regalis, whose fronds turn golden, russet-red and brown before the plant finally dies back down to the ground in preparation for its winter slumbers. Or one of the many varieties of false goatsbeard, Astilbe x arendsii, whose colourful plumes of summer flowers are replaced by golden-brown seedheads and foliage in autumn.
The true goat’s beard, Aruncus dioicus, is similarly prized by gardeners for the rich-golden hues of its autumn foliage. A tall herbaceous perennial that can quickly reach a height and spread of 2.5m x 1m, it enjoys similar growing conditions to the aforementioned hosta, Royal fern and false goat’s beard: a humus-rich, moisture-retentive but well-drained soil in partial shade.
So does the handsome, spring-flowering perennial dead-nettle, Lamium orvala, a compact, mat-forming perennial with brilliantly colourful autumn leaves.
And if you don’t mind it’s slightly thuggish habits (I know of some clever gardeners who constrain its wandering roots by planting it into the ground in large pots), then you also can’t beat the shade-tolerant Euphorbia griffithii ‘Great Dixter’ or the very similar ‘Fireglow’, both of which have glowing golden autumn foliage. That late explosion of colour is a fitting finale to a display that starts in spring, when their brick-orange leaves first emerge above ground, followed by brilliant ember- orange flower bracts in summer.
Small garden choice
Where shade isn’t too deep, try weaving in clumps of low-growing, semi-evergreen hakonechloa grass, a plant so beautiful in both spring and summer it’s easy to overlook the fact that it also gives wonderful autumn colour. This compact, versatile, ornamental grass is also happy in a pot/ container, making it a good choice for the smallest of gardens.
Other ornamental grasses with great autumn colour suitable for either sun or light shade include different varieties of Panicum, Deschampsia cespitosa, and the deciduous moor grass, Molinia caerulea subsp. ‘Heidebraut’.
The latter forms a tall but airy clump of upright foliage, its vertical stems and seed- heads turning a rich shade of rose-gold as the season progresses. Grow it in the mixed border, where it makes a dramatic autumn counterpoint to low, groundcover plants such as Geranium macrorrhizum. A versatile, hardworking perennial, the latter has richly scented leaves that turn deep shades of red and gold as temperatures begin to fall.
To add an extra fizz of colour, take a leaf from British gardener Beth Chatto and underplant with autumn crocuses (Colchicum) whose rose-pink flowers will push through the geranium’s foliage in September or October. A white-flowered form, Colchicum autumnale ‘Album’ is also available.
Sun or shade
Yet another herbaceous perennial that will add brilliant flashes of foliage colour to the autumn garden is Rodgersia pinnata. A stately foliage plant with great presence, it likes a rich moist soil in either full sun or light shade, growing to an average height and spread of 1.2m x 80cm.
At this time of year, its palmate leaves turn the most delicious shades of russet- red and chocolate-brown. Its decorative, long-lasting seed-heads are another boon.
To underscore the rich golden, chocolate and russet hues that these plants’ foliage brings to the autumn garden, grow them alongside a mix of late-blooming annuals and perennials with flowers in similarly fiery shades. Suitable candidates include different varieties of Calendula, Dahlia, Sedum, Rudbeckia, Helenium and Lobelia x speciosa.
>> THIS WEEK IN THE GARDEN (OCTOBER) <<
Pick a dry, sunny day to save the ripe seed of flowering perennials, biennials and annuals such as Astrantia (right), Eryngium, Digitalis, sweet rocket, Calendula, sunflowers, Nigella, opium poppy and cornflowers. Using a paper bag (not plastic), label carefully before placing seed somewhere dry, out of direct sunshine in preparation for cleaning and then storing in air-tight container. Always choose open-pollinated seeds rather than those of F1 hybrid varieties, as the latter won't breed true to type.
Autumn is a great time to plant garlic, which needs a long growing period and low temperatures (roughly eight weeks below 10 degrees) to crop. Break up bulbs into cloves (discard any bruised or marked) and plant in very fertile, free-draining soil in full sun, 15cm-20cm apart, in rows 45cm apart, and just deep enough that the tips are covered with a 3cm-thick layer of soil. Label clearly and make sure to keep plants weed-free. Varieties suitable for planting in autumn include 'Vallelado', Lautrec Wight', Cristo, Thermidrome', 'Marco' and 'Solent Wight'.
Clear summer bedding plants out of pots/ containers, replace top-third layer with fresh compost and replant for a winter/ spring display of colour. Hardy plants that will give sustained seasonal display of foliage, berries or flowers include Skimmia 'Rubella' and 'Kew Green', Anemanthele lessoniana, Sarcococca, Hellebore , Polystichum setiferum, trailing ivies and violas. These can be under-planted with many different varieties of spring-flowering bulbs.
