When carefully chosen and planted, wallflowers add vibrant colours and scent to the garden throughout and sometimes beyond spring.

Yet it's hardly a surprise that they are unfashionable. The serried ranks of fusty municipal plantings are certainly offputting, the varieties available all too often sore on the eyes. Some of the clashing colours in mixed selections and even on individual plants such as Sweet Sorbet are horrifying.

There's so much more to wallflowers – the erysimum genus – than the rather hackneyed Bowles' Mauve. Its flowers are pleasant, it has a long flowering season and it works well with other plantings. However, I would go for more characterful varieties. They can be tricky to source and suppliers generally only carry two or three varieties, but it is worth tracking these gems down.

There are about 180 species including two garden types: sub-shrub perennials and biennials, and alpines. Besides the full sun all wallflowers require, the herbaceous sub-shrubs also need fertile, well-drained soil, while those suited to alpine conditions like poor, gritty ground. These occur naturally along cliff edges and on scree slopes. I even had one growing at the top of a 10ft wall in my Edinburgh garden years ago. With such perfect conditions, this fellow had been on the go for many years, but wallflowers often curl up and die after three or four years, so you should aim to replace your stock every couple of years.

Sow biennial wallflowers over the next few weeks, remembering that you won't get flowers until next year. Sow them in a seed tray and prick out into 8cm pots, leaving them to grow on until the end of August. If you're planting them in the open ground, you'll have cleared some summer flowering plants so you should have enough space in a bed. In August, the soil is still warm enough to allow young plants to get quickly established before the winter shutdown. Plant boldly in large drifts, with around 15 plants grouped together, 30cm apart. Nip out growing shoots to stimulate more bushy plants and lots more flowers.

Smaller perennial alpine species are well suited to rock gardens and containers. The planting mix should be 50:50 compost and coarse grit. When planting in containers, you're almost adding a little compost to the coarse grit rather than the other way round. Wallflowers also prefer alkaline soil, but will cope with anything but the most acidic conditions.

When your wallflowers start flowering, keep the show on the road by cutting or deadheading all the time. If you don't, flowering will stop prematurely during a warm spell and the plants will set seed in no time at all.

Taste is subjective by its nature but, as ever, I'm only going to recommend varieties that appeal to me. And I do insist on a strong scent that's also a magnet to pollinating bumblebees, so forget doubles. A good alpine choice is Erysimum capitatum var purshii, Pursh's wallflower. This native of the Rocky Mountains in Colorado makes tight rosettes of bright green leaves, with short-stemmed racemes of superb bright-yellow flowers that become paler with age.

Another perfect candidate for a planter is Parkwood Gold. It's much more compact, forming a dense carpet of wonderful golden-yellow flowers. The same applies to Moonlight. This one has refreshingly lemony flowers, rising from a mound of dark, evergreen foliage. If you're using containers, I reckon it's best to put them on a wall – right in your nose and face.

By and large, the alpines you can track down only have varying shades of yellow flowers, but sub-shrubs enjoy a much wider range of colours. The flowers of Erysimum Vulcan are a wonderfully deep, rich crimson-black, while the velvety Fire King offers a brownish, toffee-apple orange show. Yet another beauty is Ellen Wilmot with pink, almost watermelon-coloured flowers that smell out of this world.

Look out for some of these beauties – you'll find it's well worth the trouble.

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