The root of 3

Three plants that look good together all year round: Melianthus major, Artemisia lactiflora "Guizhou" and Allium christophii

One or two pieces of your favourite flora are good company but three can begin to seem crowded - unless you know what goes with what. Grown together with their contrasting leaf colours, textures and growth habits these plants form an effective combination over a long season.

This striking combination needs a sunny sheltered spot, ideally against a wall or a fence, not for the Artemisia or the Allium though they will both appreciate it, but for the tender Melianthus or honey bush, the dominant plant of this group.

So called because its strange flowers of reddish-brown bracts and green stamens exude a honey-like liquid, the shrubby, hollow-stemmed honey bush can easily attain a height of six or seven feet in one summer. Its home is South Africa, where it is evergreen, but on our shores it will grow only in the milder districts. Even then it often gets cut down by frost, though this is no real problem, for it springs back readily and strongly from the base. If the frost doesn't get it then the secateurs probably should, for it has a sprawling nature that is best kept in check. This also produces larger more luxuriant leaves - the plant's main asset. Graham Stuart Thomas, that great authority, says of the honey bush that it has "probably the most beautiful large foliage of any plant that can be grown out of doors in these islands". The leaves are huge, up to 18 inches long, glaucous blue to sea-green, curved and deeply toothed and when you brush past they bruise and give off a strong, musty smell.

The second plant of the group - Artemisia lactiflora "Guizhou", the purple form of the white mugwort - grows on you the more you see it. It's an incredibly well-behaved perennial with an airy, subtle dignified nature and quiet virtues. From a base of finely cut, fern-like, purple-green foliage that forms a neat mound even in winter, it throws up long, elegant purple-flushed stems up to five feet high. This height often relegates it to the back of the border, but it is lost here and needs to be grown where the whole length of the plant can be seen.

It flowers late, from August to October, producing long-lasting sprays of creamy white flowers. Reluctantly I admit it has one flaw - the off- white sprays can look a little dirty if planted next to whiter flowers. But generally it associates easily with other plants, enhancing the qualities of its neighbours. Growing through and in front of the honey bush, the Artemisia's fine texture and dark stems contrast well with the scale and shape of the blue-green leaves.

The last of the trio is one of the onion bulbs, Allium christophii. The leaves have nothing to recommend them, but they soon die away and are obscured by the foliage of the other plants. What you do see are the flowers - huge spherical purplish-violet star-bursts up to 10 inches across, open in summer at a couple of feet high and supported amidst the purple- green foliage of the Artemisia. For up to a month they keep their colour and, when that's over, turn into dried seed heads almost as spectacular as the flowers.

John the Gardener

plant of the moment

Winter colour, winter colour. How to achieve it without messy flowers or vulgar berries? By now, the leaves will have fallen from the Cornus alba plants, to reveal blood-red stems which look wonderfully minimalist and spiky against a frosty or snowy background - colourful without being blowsy, dignified not showy. This makes it a godsend for sophisticated urban gardeners who want to keep an interesting cold-weather spot of brightness, but would never descend to the frightful splashiness of winter pansies or bright-pink cyclamen or any of the other standards. Grown in a narrow border Cornus doesn't have to take up too much space and can do wonders for gloomy corners of the patio once the terracotta planters have been taken in out of the frost. Commonly called the dogwood, the elegant stems of Cornus come in different shades; Cornus alba "Kesselringii" is purple, while Cornus sanguinea "Winter Beauty" or "Winter Flame" has striking orange-yellow shoots. Some varieties are grown for their showy summer bracts rather than their bright stems; look instead for varieties such as Cornus alba "Sibirica". Cornus will tolerate a range of soils and locations but, for maximum stem colour, plant in full sun. Prune old stems hard in spring, as it's the young stems that are coloured. Hardy.

CORNUS

After the leaves have fallen, its brightly coloured stems can bring a spot of spiky colour to a winter garden