Evergreens give a garden its bones

Most British borders look magnificent in June and rather bleak by Bonfire Night. Evergreen shrubs and trees solve that problem. They are the skeleton of the garden: they hold the outline of a bed, screen an awkward corner, divide a long plot into rooms and give the eye somewhere to settle when the herbaceous planting has collapsed into the soil.

The catch is scale. A leylandii hedge or a sprawling laurel will swamp a modest garden within five years, and then you spend every weekend fighting it with loppers. Choose compact, slow-growing varieties instead, plant them with enough room to reach their natural size, and you will spend far more time enjoying the garden than pruning it.

Matching the plant to the spot

Before you buy anything, look honestly at the site. Is it baked by midday sun, or shaded by a fence for most of the day? Does the soil drain freely, or sit heavy and wet through winter? Evergreens are long-term tenants, so getting this right saves years of disappointment.

• Formal clipping: box remains the classic choice, but with box blight and box tree caterpillar about, many gardeners now use Ilex crenata, Lonicera nitida or yew for the same tight, dark green geometry.
• Shade and dry roots: Sarcococca confusa (sweet box), skimmia and Fatsia japonica all cope with dim corners under trees, and sarcococca rewards you with intensely fragrant winter flowers.
• Sun and shelter: pittosporum, hebe, Choisya ternata and rosemary thrive in a warm, protected spot. In colder counties, treat them as slightly tender and keep them out of frost pockets.
• Colour through the year: Euonymus fortunei cultivars, golden hebes and Photinia bring variegation or red new growth to lift a green scheme.

Trees for small plots and pots

A tree gives a garden height and a sense of maturity faster than anything else, but in a courtyard or a narrow town garden you need something that behaves. Bay (Laurus nobilis) is ideal: it clips beautifully into lollipop or cone shapes, supplies the kitchen, and grows happily in a large container for years. Give it a sunny, sheltered wall and keep it well watered in summer.

Olives suit a hot patio against a south-facing wall, and their silver foliage looks wonderful with grey stone paving and lavender. Yew is slow enough for a big pot and can be clipped into a strong architectural shape, though it resents sitting wet. For something with a little more softness, consider a compact holly or a clipped Ilex crenata standard, which gives you the formal look of box without the disease risk.

Whatever you choose, plant trees in containers with a loam-based compost such as John Innes No. 3, add a layer of crocks or gravel for drainage, and stand the pot on feet so water never pools underneath.

Underplanting for seasonal interest

This is where the magic happens. Evergreens provide the constant, and bulbs and perennials provide the change. Because most spring bulbs flower and finish before the shrubs put on much growth, you can pack them in closely without overcrowding.

• Late winter: snowdrops, Cyclamen coum and winter aconites around the feet of sarcococca and skimmia.
• Spring: narcissi, muscari and crocus naturalised beneath yew and holly, plus epimedium and hellebores for texture in shade.
• Summer: alliums pushing up through low evergreen mounds, hardy geraniums and heucheras filling the gaps.
• Autumn and winter: ferns, ivy and grasses to soften clipped edges, with berries and coloured stems carrying the display.

Plant bulbs in generous drifts rather than neat rows, and let perennials knit together so bare soil disappears. A mulch of bark or leafmould each spring keeps weeds down and moisture in.

Watering, feeding and the seasonal rhythm

Containers need more attention than borders. Water thoroughly rather than little and often, and feed with a balanced fertiliser from spring to midsummer. Watch for vine weevil grubs in pots, which hollow out roots and cause sudden collapse — nematodes applied in late summer are the reliable organic answer.

In the open ground, mulch after planting and water well through the first two summers. After that, most established evergreens look after themselves.

Pruning is the one job that keeps structure crisp. Clip yew and box in late summer, when growth has firmed up, and avoid cutting into old wood on pinks, rosemary and hebes, which rarely regrow from bare stems. Spring-flowering evergreens such as Pieris and Rhododendron are best trimmed straight after flowering, so you do not sacrifice next year's buds. Tidy hebes and pittosporum lightly with shears in midsummer to keep them bushy and dense.

Do that little bit of maintenance each year and your garden will hold its shape through every season — green, generous and quietly full of life in the depths of January.