Gardeners are always looking forward so are beginning to plan next year’s spring show. For me, wallflowers, Erysimum, are a must. There’s so much more to these wonderfully scented spring flowers than is often realised. They can be trimmed to make a fine specimen plant, with their gorgeous grey-green a background for so many flowers throughout the year.

With the right growing conditions, wallflowers thrive for several years. All they need is the sun and a little very free-draining soil. Their name tells all. Wallflowers have long been seen growing on ruined walls, like those at Neidpath castle in the Borders, six centuries ago.

And one happily grew out of a high boundary wall in my Edinburgh flat many years ago.

Gardeners often buy potted wallflowers in spring, then whip them out to make room for annual bedding plants. And to reduce this very expensive and wasteful method, some buy plugs or bare root wallflowers now, but still treat them as annuals.

Why not enjoy the plant’s potential, treat it as a short-lived perennial, trimming and caring for it and letting it adorn the bed for several years? Or even go the whole hog and grow from seed as I do.

Unless you’re saving seed, deadhead to force the wallflower to put its energy into developing foliage. The main job now with this season’s plants is tidying up by first removing any remaining deadheads.

Given half a chance, wallflowers produce long, straggly stems. The bare, ropey stems are unsightly and so tough they take some composting, but you want an attractive bushy plant. Cut sections of stem back to a growing shoot which the plant will have produced by now. If you cut back below the lowest shoot, you’ll kill the stem.

Start pruning one-year old wallflowers now to prevent them developing bare stems, and keep them pruned and shapely every autumn, so they will provide a fine backdrop for other border flowers and continue into winter long after the rest have died back.

If buying new specimens just now, colours include lemony cream, egg yolk yellow, orange, tawny and dark red. These dark red varieties with various sanguinary names have often been the most popular.

The favourite variety in the 17th century was ‘Bloody Wallflower’. And then there are crimsons, purple and rose, along with some strange creatures that start purple and end up yellow. Even wallflowers can’t escape breeders’ fantasies.

Your choice of colour may depend on whether you’re planting in a bed or a container. A spring bed often has lots of yellows, so I always go for stronger, contrasting colours, like oranges and red.

The classic pairing is wallflowers with tulips and here the colour combinations are almost endless. Rich, velvety shades work superbly and even the normally clashing oranges and purples can be stunning. But you have to get it right and catalogue pictures are sometimes slightly different to what you expect, with jarring consequences. Balancing colours is harder than it seems.

Wallflowers also thrive in large containers and the tulip/wallflower combination works well because their growing needs are virtually the same.

Provide sun and very good drainage, moist conditions while flowering, followed by little water.

Centre a wallflower, with tulips round the edge. Mix 3 parts compost to 1 part horticultural grit with a thin layer of grit for top dressing.

As the tulips die back after flowering, the wallflower grows to largely fill the space. In autumn, scrape off the grit, feed with a thin layer of home-made compost and replace the grit. Then trim the wallflower.

Tulips and wallflowers are short-lived perennials, so dwindle after a few years and need replacing.

Plant of the week

Malus baccata ‘Pink Glow’ is a Siberian crab apple that bears clusters of small, bright pink fruits. Perfect for apple jelly. The tree is very hardy with excellent cold tolerance.