How to Grow Erysimum (Wallflowers) in Your Garden

Introduction to Erysimum and Wallflowers

If you’ve ever walked past an old stone wall and noticed cheerful, sweet-smelling flowers tucked into the cracks, chances are you were looking at wallflowers — or Erysimum, to give them their proper name. These lovely plants belong to the Brassicaceae family and have been a staple of European gardens for centuries. That habit of colonizing old walls is actually where they get their common name, since they genuinely do thrive in the crevices of stonework where most plants would give up entirely. These days you’ll find them growing in gardens all over the world, valued for their wide range of colors and that warm, honey-sweet scent that drifts through the air on spring evenings.

There are two main types of wallflowers you’ll come across as a gardener. First, there’s the classic biennial wallflower (Erysimum cheiri), which you plant one year and it flowers the next. Then there are the perennial types, with Erysimum ‘Bowles’s Mauve’ being probably the most popular. Perennials tend to have a slightly shorter season of bloom, but the trade-off is that they come back year after year without you having to replant them — which makes them a great option if you want colour in your borders without a lot of fuss.

The colour range wallflowers offer is genuinely impressive, running from deep velvety reds and rich purples right through to bright oranges, soft yellows, and creamy whites. Many varieties also throw in bicolour blooms for a bit of extra interest. Whether you’re working with a formal border or going for a more relaxed cottage garden feel, wallflowers fit in almost anywhere. They’re also compact enough to work well in containers, window boxes, and raised beds, so even if you’re short on space, you can still enjoy them.

Choosing the Right Varieties for Your Garden

Picking which wallflowers to grow is honestly one of the most enjoyable parts of the whole process, simply because there are so many good options. For biennial types, the ‘Persian Carpet’ series is worth a look — it delivers a gorgeous mix of warm tones including bronze, crimson, and gold, all on compact plants that stay under about 30 centimetres. The ‘Harlequin’ series is another firm favourite, with large, vibrant flower heads across a wide colour spectrum that look fantastic when you mass them together in a border or formal bed.

If you’re leaning towards perennials, Erysimum ‘Bowles’s Mauve’ is the one most gardeners reach for first, and it’s easy to see why — it produces soft mauve-purple flowers almost continuously from late winter through to early summer, and the grey-green foliage stays looking good even when it’s not in bloom. Other perennial varieties worth considering include ‘Apricot Twist’, which has beautiful bicolour flowers in shades of apricot and orange, and ‘Winter Orchid’, which is particularly useful because it’ll flower during mild winter spells when not much else is going on in the garden.

It’s also worth thinking about where each plant is actually going to sit in your garden before you buy. Compact varieties work brilliantly as edging along pathways or at the front of a border, while taller ones can fill that middle ground between low-growing plants and taller shrubs. If you like having cut flowers in the house, wallflowers are excellent for that too — most varieties last up to a week in a vase and bring that lovely scent indoors with them. Just check the expected height and spread before you buy, so you’re not surprised later.

Ideal Growing Conditions and Site Selection

Wallflowers are pretty adaptable, but like any plant, they do their best when the basics are right. They want a spot that gets full sun for most of the day — at least six hours of direct light is ideal. They’ll put up with some shade, but plants grown in shadier spots tend to get leggy and produce noticeably fewer flowers as they stretch toward the light. South or west-facing borders are your best bet, especially if you garden somewhere with cool summers where getting as much sun as possible really matters for flowering.

Soil is where things get particularly important. Wallflowers really want well-drained soil with a pH somewhere between 6.5 and 7.5 — neutral to slightly alkaline. Heavy clay that sits wet through winter is bad news for them, as they’re quite vulnerable to root rot in waterlogged conditions. If that sounds like your garden, it’s worth spending some time before planting digging in plenty of grit, horticultural sand, or composted organic matter to open up the drainage. It makes a real difference to how the plants perform.

One of the things that makes wallflowers so endearing is how happy they are in poor, thin soil — which is why you so often see them thriving in wall crevices and rocky spots where nothing else would bother. In very rich, heavily fed soil, they tend to put their energy into producing masses of lush foliage instead of flowers, so it’s actually better not to over-feed them, especially with anything high in nitrogen. A moderately fertile soil with a little well-rotted compost worked in at planting time is about right. Good air circulation around the plants also helps keep fungal disease at bay, which can sometimes be an issue with members of the Brassicaceae family.

How to Sow and Plant Wallflowers

With biennial wallflowers, you start the process in late spring or early summer the year before you want them to flower. You can sow seeds directly into a prepared seedbed outdoors in rows about 15 centimetres apart, at a depth of around 6 millimetres. If outdoor conditions are too wet or cold at sowing time, starting them in trays or modules under cover works just as well. Germination usually happens within one to two weeks in warm weather, and the seedlings grow on quickly after that. Thin them out as they develop to avoid crowding — good air circulation from an early stage gives you stronger, healthier plants.

Once the seedlings have their first set of true leaves and are around 5 to 8 centimetres tall, move them to a nursery bed where they’ll grow through the summer, spaced about 15 centimetres apart. Water them in well after transplanting. One technique that experienced wallflower growers swear by at this stage is pinching out the growing tip of each young plant. It sounds simple, and it is, but it makes a big difference — it encourages the plant to branch out and become bushier, which means many more flowering stems come spring rather than just one central spike.

The final move to their flowering positions happens in autumn, typically somewhere between September and November, before the ground gets too cold. Space plants between 25 and 40 centimetres apart depending on the variety, with the bigger ones needing more room. When you plant them, firm them in really well — wallflowers have a bit of a reputation for being heaved out of the ground by winter frosts, and loose planting makes this worse. There’s an old saying that wallflowers should be “planted with your heel,” meaning you should actually use your foot to press the soil firmly around the roots. Water in after planting and check on them occasionally through winter, pushing back any that have been lifted by frost.

Perennial wallflowers are usually bought as young plants from a garden centre, or propagated from cuttings taken from an established plant. They’re best planted in spring or early autumn to give their roots a chance to settle before the demands of summer heat or winter cold kick in. The same rules about drainage and firm planting apply here. Because perennial wallflowers tend to get a bit woody and less productive as they age, many gardeners take semi-ripe cuttings every couple of years to keep a supply of fresh, vigorous plants going.

Caring for Wallflowers Through the Seasons

Once they’re settled in, wallflowers are pretty low-maintenance plants that don’t ask for much to look their best. Through autumn and winter, your main jobs are checking that plants haven’t been lifted by frost and pressing them back down if they have, and making sure the soil isn’t sitting waterlogged around them. In colder or more exposed gardens, a light mulch of well-rotted compost or bark chips around the base of the plants can help protect the roots through the worst of the cold — just be careful not to pile mulch up against the stems themselves, as that can cause rotting.

When spring arrives and growth picks up, a light feed makes a noticeable difference. A balanced granular fertilizer or a liquid feed with high potash — tomato fertilizer works well — can encourage more flowers and keep the display going longer. Deadheading spent flower spikes on both biennials and perennials helps extend the season by stopping the plant from putting its energy into seeds. That said, if you want to collect seed from biennial varieties to sow the following year, hold back from deadheading a few stems and let them ripen before the pods split and scatter.

Wallflowers are fairly tough when it comes to pests and diseases, but there are a couple of things to keep an eye on. Club root is the most serious problem — it’s a soil-borne disease that affects all members of the Brassicaceae family, causing stunted growth and distorted, swollen roots. The best way to reduce the risk is to avoid planting wallflowers in the same spot year after year and to rotate where you grow them around the garden. Flea beetles sometimes leave small round holes in the foliage, but this rarely does any real harm. Aphids can appear on soft new growth in spring but are usually easy enough to deal with by hand or with a strong blast from the hose.

Combining Wallflowers with Other Plants

Part of what makes wallflowers so much fun to grow is how well they work with other plants. The most classic combination — and one that’s stood the test of time for very good reason — is wallflowers with tulips. The two flower at almost exactly the same time, and the colour ranges available in both are so complementary that it’s hard to go wrong. Deep red tulips rising above a carpet of rich orange wallflowers gives you a warm, fiery feel, while purple and white tulips paired with yellow wallflowers is a more sophisticated contrast that’s been popular in formal gardens for generations.

Beyond tulips, wallflowers combine beautifully with all kinds of other spring-flowering bulbs and perennials. Forget-me-nots give you a soft blue haze at ground level, muscari adds deeper purple tones, and narcissus or daffodils bring lightness and height. In a more naturalistic setting, wallflowers can be allowed to self-seed into gravel or along the foot of a wall where they’ll gradually create that effortless, cottage-garden feel that takes years to achieve deliberately but seems to happen all by itself when plants are left to get on with it.

With perennial wallflowers, the planting combinations extend across more of the year. Erysimum ‘Bowles’s Mauve’ is particularly good for this because it blooms for so long — in early spring it sits nicely alongside hellebores and pulmonarias, in late spring it works with alliums and early geraniums, and through summer its mauve flowers make a lovely backdrop for roses, salvias, and catmint. The grey-green foliage that many perennial wallflowers carry is also quietly useful as a foil for brighter neighbouring plants throughout the year, even when the wallflower itself isn’t actively flowering.

Propagating and Saving Seeds

Learning to propagate your own wallflowers is well worth the effort — it lets you build up large numbers of plants for very little money and means you can hold onto particularly good forms from one year to the next. With biennials, seed is the way to go. If you have a plant with a colour or vigour you want to preserve, let a few seed heads ripen fully on the plant until the pods turn brown and papery. Cut the stems and hang them upside down in a paper bag somewhere warm and dry. As the pods dry out further they’ll split on their own and the seeds will drop into the bag, ready to store or sow straight away.

Perennial wallflowers — particularly named varieties and hybrids — are a different story. These are best propagated from cuttings rather than seed, because seeds from perennial hybrids often don’t come true to the parent plant and can produce offspring with quite different flower colours or growth habits. To take cuttings, choose healthy shoots that aren’t flowering in early summer, cut them to about 7 to 10 centimetres just below a leaf node, strip off the lower leaves, and push them into a mix of equal parts peat-free compost and horticultural grit. Keep them somewhere sheltered and lightly shaded, and they should have rooted within four to six weeks.

There’s something genuinely satisfying about growing wallflowers from scratch — whether that’s nurturing a seed through germination and transplanting, pinching out the tips, and then waiting through the winter months, or striking a cutting and watching it root into a strong young plant. That extended relationship with a plant makes you pay closer attention, and you end up learning things about growing conditions and timing that improve your gardening more broadly. Whether you’re just starting out or you’ve been gardening for years, raising wallflowers from seed or cuttings is one of those experiences that reminds you why the whole thing is so worthwhile.