Evergreen perennials
Words: Graham Rice
Most gardeners recognise the value of evergreen shrubs in the winter, but evergreen perennials seem to draw far less attention. This is unfortunate because some have real presence as they add texture and colour at a time of year when interest is badly needed.
Evergreen perennials also provide partners, background and shelter for early bulbs in the open ground and in containers. Their ground covering capabilities also help deter weeds in mild spells. All in all, evergreen perennials are unjustly underused for their winter appeal.
Ajuga reptans ‘Catlin’s Giant’
All bugles make a low evergreen carpet, extending around and under deciduous shrubs and providing spikes of blue, pink or white spring flowers. ‘Catlin’s Giant’ is more vigorous than most with deep purple-bronze winter foliage, through which clumps of snowdrops can bloom against a contrasting background. Working some fine mulch in among the foliage before the snowdrops emerge helps keep the bugle looking good. Height: 20cm (8in).
Arum italicum subsp. italicum ‘Marmoratum’
A real star of the winter garden. Not only are the dark green, arrowhead leaves beautifully marked with white veins, but the foliage looks fresh and bright even in the darkest days. Leaves may collapse after a frosty night but, as with hellebores, they soon revive. Another that is good with early bulbs in sun or shade, and with the added bonus of clusters of bright red berries in summer. Height: 35cm (14in).
Carex elata ‘Aurea’
Discovered as a small shoot on the ordinary green-leaved form of the species by the great plantsman E. A. Bowles. This upright, bright yellow-leaved form with a slender green edge to the foliage is often known as Bowles’ golden sedge. Vivid in colour, the leaves gleam in the winter sunshine and brighten up dull days. Happy to be surrounded by ‘Catlin’s Giant’ bugle or situated in shallow water or wet soil. Height: 40cm (16in).
Carex oshimensis ‘Evergold’
Spreading in growth and maturing to a plant that is more than twice as wide as it is high, each long narrow leaf features a deep green edge and broad, white (sometimes slightly creamy) central stripe. The contrast between the edges and the centre of the leaf is striking. A little shade enhances the colouring and soil that does not dry out is preferred.
Height: 25cm (10in).
Dryopteris erythrosora
Sometimes we forget that there are hardy ferns which are evergreen, and this is one of the best. The new fronds emerge as bright coppery-pink in spring, mature to a rich green colour. In autumn they develop coppery orange tones that last through the winter becoming yellow by February. Be sure to cut back the old fronds in early spring so that the colourful new growth is visible. Height: 60cm (124in).
Euphorbia characias ‘Portuguese Velvet’
All forms of Euphorbia characias are good in winter; they have a strong presence with evergreen foliage often revealing blue tints, complimented by bold heads of chartreuse flowers. With ‘Portuguese Velvet’, the bluish leaves are covered in fine hairs that make the leaves seem edged in silver. Smaller than many, this is a fine gravel garden plant.
Height: 60cm (2ft).
Heuchera ‘Regina’
One of the toughest and most resilient of all heucheras, ‘Regina’ features reddish-purple foliage overlaid with silver markings and a slightly reflective sheen. The leaves overlap each other evenly to create a neat mound of foliage, from which tall spikes of pink flowers emerge in spring. Excellent in containers, and takes drought better than most. Developed in Pennsylvania by Charles Oliver who began the current fashion for heucheras.
Height: 25cm (10in).
Heuchera ‘Sashay’
The striking ruffled and sharply toothed foliage of this unusually tough and resilient selection, is green on the upper surface and purple on the underside. The ruffling of the leaves reveals glimpses of the dark undersides all over the plant and the effect is lovely. ‘Sashay’ is sport of another AGM winner, ‘Purple Petticoats’, which is also a good evergreen perennial for winter. Makes an attractive mound; wider than high. Height: 25cm (10in).
Ophiopogon planiscapus ‘Nigrescens’
Famous for its slender and almost uniquely black, arching foliage, this resilient plant spreads slowly and steadily. The shoots and foliage build into a low dense cover making it an ideal front-of-the-border plant where its leaves can overhang a pale path. Makes a fine background for clumps of early crocuses and snowdrops and also features purple summer flowers and purple-black berries. Suffers from a profusion of made-up names. Height: 15cm (6in).
Vinca minor ‘Argenteovariegata’
With wiry stems snaking across the soil in sunny and shady places and intercrossing into a dense ground covering mat, the neat green leaves are edged with cream. The foliage also has the distinctive habit of producing occasional leaves which are half cream or perhaps entirely cream. Pale blue flowers open in spring. Ideal in the shade of deciduous shrubs. Height: 15cm (6in).