Not many of us, if indeed any of us, would place winter at the zenith of the gardening calendar. But for gardeners in temperate countries, half the gardening year is spent going into, coming out of, or in the chilly teeth of winter, so it is sensible to make our gardens as interesting as possible for the season.
The first thing to do is grow plants with interesting winter flowers, stem colour or bark. Not so hard, since winter flowers are often the most fragrant – the more scented the flowers, the better the chance of a visit from a helpful bumblebee or moth. Viburnum x bodnantense and its cultivars ‘Dawn’, ‘Deben’ and ‘Charles Lamont’ are popular, but get quite big unless pruned every other year, ideally, with around a third of the old wood removed. They have waxy, frost-resistant pink flowers and decent autumn colour, but are otherwise anonymous for the rest of the year.
Fragrant box bushes, Sarcococca confusa and S. humilis, are easier to fit in a smaller garden, in part because they remain manageable at around 1.5m (5ft) tall and across, but also because the evergreen foliage is genuinely handsome and the form quite compact, making them a viable alternative to topiary. And both give off a gorgeous scent from small, spidery, creamy-white flowers, which are followed by dark purple berries with a metallic sheen.
Stem and bark interest plants come to the fore in winter. Choose from the colourful-stemmed dogwoods – from bright red Cornus alba ‘Sibirica’ to greenish gold C. sericea ‘Flaviramea’ via the near black of C. alba ‘Kesselringii’ – to the bold-stemmed willows. Then there are acer, birch and cherry trees, which have beautiful bark. I’d single out Acer griseum and Prunus serrula, the former with shaggy, cinnamon-coloured bark and the latter with peeling, glossy mahogany bark.
But there is an even easier way to extend interest. Most gardens will have plants that, in the words of Dutch designer Piet Oudolf, ‘die heroically’. These are perennials such as late-season flowering grasses and late-flowering plants. Historically the autumn gardening calendar culminated with a great rush to cut down every plant to ground level, to ‘put the garden to bed’. This may result in a neat and tidy plot but it also removes anything of any aesthetic value; those ‘heroic’ plants that can grace the garden with subtle hues and skeletal interest right through winter if given the chance.
At Harlow Carr, the Royal Horticultural Society garden I curated for five years, I designed the main borders very much with this in mind. So while spring, summer and autumn colour were major considerations, I also looked for plants with interesting foliage, handsome seed heads or good skeletal structure. Miscanthus are a backbone to the planting: these grasses look good from spring, when the foliage gets going, through to late summer with their plume-like flowers. Better still, they hold up to winter with handsome, straw-coloured foliage and faded cream flower heads. Miscanthus come in a range of shapes, sizes and colours, from the tiddly M. ‘Little Kitten’ at around 1m (3ft) tall to the beautiful monster that is M. ‘Goliath’. They are invaluable, providing you have a spot in full sun or part shade and moisture-retentive soil.
The North American prairie grass Panicum is another stalwart of the borders: it has light, airy flower heads with bead-like seeds that take on a jewelled quality when dusted with frost. Stipa brachytricha is another useful grass. It’s compact at around 1.4m (4½ft) with feathery flower plumes that fade from metallic purple to almost white. Even the midsummer-flowering S. gigantea can add presence and interest. Though the airy, oat-like flower panicles may have long gone, the stems remain like golden wands.
The light foliage of grasses makes the perfect backdrop for plants with interesting winter seed heads. Perhaps the best of these are the border sedums such as Sedum ‘Matrona’ and ‘Herbstfreude’, which flower right into early winter and then grace the garden with fat, flat umbels of dark seeds that come to life when encrusted with frost. They were made for this moment; rigid enough to stand up to a battering and still perky even in the depths of the season. Echinacea seed heads are fascinating: the ray florets fall away to leave just the bristly central boss, which in frosty conditions can look as if it’s been rolled in icing sugar. Perhaps the biggest surprise is the longevity of interest of Iris sibirica hybrids. These are plants that finished flowering in May or early June, yet their seed heads still look interesting in December.
While my aim is always to try to let perennials stand until late February, the moment plants collapse under the battering of wind, rain or snow, I do intervene and have a tidy up – the object of the exercise is interest, not a mess!
The final group of plants for your winter border are those with structural interest. In summer, I suspect hardly anyone notices the tightly clipped Buxus cones in the main borders at Harlow Carr, but in winter they are vital, creating rhythm through the length of the beds and holding the whole planting together. Topiary shrubs of yew, box, Ligustrum and so on, can provide structural backbone to a garden, and a cloud-pruned evergreen shrub (where the foliage is topiary-pruned to form a series of cloud-shaped ‘pads’ on the stems) can become a real eye-catcher.
Rather more ephemeral are stands of Angelica gigas, which resemble cow parsley on steroids, and the native teasel, Dipsacus fullonum, whose great, bristly seed heads are much loved by finches. To these, you could add the white-silver foliaged Onopordum acanthium, a large thistle that spreads around the garden by seed, or the smaller but equally wayward Eryngium giganteum.
So, allow the plants that have given you joy through summer and autumn to continue to do so. Add a few winter-interest specimens and the result will sustain the soul until springtime rolls around.
Plants of interest to add colour and shape in winter
Cornus alba ‘Sibirica’
The red-barked dogwood thrives in a sunny spot
Cornus sericea ‘Flaviramea’
Add a goldish green to the garden with this deciduous shrub
Cornus alba ‘Kesselringii’
This purple-black dogwood will take to acidic and wet soil
A hardy maple whose dark red bark peels away, to reveal orange bark beneath
Before it flowers in the spring, this Tibetan cherry boasts a striking copper-red bark
This article first appeared in Saga Magazine.