Biennial
How to grow wallflowers
Erysimum cheiri
Wallflowers are hardy biennials sown in May or June and planted in their flowering positions in September or October, 25 to 30 cm apart, to bloom from March to May. Most gardeners buy them as bare-root bundles in October, which must go in the same day. They need full sun and free-draining soil that is neutral to alkaline. Remember that the wallflower is a member of the cabbage family: it gets clubroot, so keep it off ground where brassicas have had the disease.
- Hardiness
- Fully hardy biennial
- Position
- Full sun
- Soil
- Free-draining, neutral to alkaline
- Ideal pH
- 6.5 to 7.5
- Water
- Low to moderate
- Feeding
- Light feeder
Sowing and planting wallflowers
WhenSow May to Jun; plant out Sep to Oct; flowers Mar to May
Starting off
Sow May to Jun in a seedbed outdoors 1 cm deep, germination 7 to 14 days at 15 to 20 °C. Thin to 10 cm, pinch tips at 15 cm for bushiness and transplant Sep to Oct, firming hard; bare-root bundles bought in Oct are planted the same day. Perennial Erysimum 'Bowles's Mauve' comes from 8 cm cuttings in Jul to Aug.
Spacing and planting
Plant 25 to 30 cm apart in beds, 20 cm in a window box; sow 1 cm deep in rows 30 cm apart. Fine in a 30 cm pot for spring display.
Varieties worth growing
- 'Blood Red'
- Deep velvety crimson, 45 cm, strongly scented; the traditional partner for yellow or white tulips.
- 'Cloth of Gold'
- Large golden yellow flowers with the strongest scent of the common bedding varieties.
- 'Persian Carpet'
- A mix of cream, apricot, rose, purple and gold in soft shades; good where you want one sowing to give a tapestry.
- 'Sugar Rush' series
- Compact at 30 cm and bred to flower in autumn as well as spring; sold as plug plants for pots and window boxes.
- Erysimum 'Bowles's Mauve'
- A shrubby perennial wallflower with mauve spikes for much of the year; short-lived, so root cuttings in summer.
Wallflowers month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Firm back any plants lifted by frost.
- February
Give a light feed late in the month if the soil is poor.
- March
First flowers. Feed now if you did not in February.
- April
Peak flowering. Deadhead to keep the display going.
- May
Sow thinly in a seedbed, 1 cm deep. Pull bedding plants once flowering ends.
- June
Last sowings. Cover seedlings with mesh against flea beetle. Thin to 10 cm.
- July
Pinch out the tips at 15 cm for bushy plants. Take cuttings of 'Bowles's Mauve'.
- August
Water the nursery row in dry spells.
- September
Move plants to their flowering positions with as much root as possible. Firm in hard.
- October
Plant bare-root bundles the day you buy them, with tulips between. Finish this month.
- November
Nothing to do.
- December
Nothing to do.
Feeding wallflowers
A light feeder. Soil pH matters more than fertiliser: check it, lime if it is acid, and give one half-rate balanced feed in late winter. Rich soil gives soft, leafy plants that suffer in frost.
Low, a brassica relative; over-rich soil gives leaf, not scent.
Feeding plan
Before autumn planting, acid soil only
Garden Lime (calcium carbonate)
Only if a test shows a pH below 6.5: up to 0.5 kg/m², the label rate for a typical bed, worked into the top 15 cm. Lime also makes clubroot less likely. If the pH is 6.5 or above, none.
February or March, beds
50 g/m², half the label rate of about 100 g/m², scattered between the plants and hoed in lightly: a generous handful per square metre. Once.
February or March, pots and window boxes
2 g per litre of compost, the low end of the label top-dress: 24 g on a 30 cm pot holding 12 litres, watered in.
Wallflower is in the cabbage family, so it shares clubroot with the vegetable brassicas (hence the links to cabbage and Brussels sprouts) and Mycorrhizal Fungi Powder is not recommended for it.
Signs to watch
Purple-tinted leaves in Nov
Cold and phosphorus lock-up
Ignore
Floppy, lush plants
Nitrogen excess
Firm planting and no feed beyond a light one in Mar
Pests, diseases and problems
Plants stunted and wilting on sunny days; roots swollen into knobbly, distorted lumps
Clubroot, a soil-borne disease of the cabbage family that can persist in soil for up to 20 years
There is no cure. Bin affected plants with their roots, lime acid soil to pH 7 or a little above, improve drainage, and do not plant wallflowers where brassicas have had clubroot. Raise your own plants in pots of fresh compost rather than buying field-grown bare roots if your soil is clean and you want to keep it so.
Seedlings peppered with small round holes in June and July
Flea beetle, worst in hot, dry weather
Cover the seedbed with fine insect mesh from sowing and keep the seedlings watered so they grow through it quickly.
Yellow patches on the upper leaf surface with white fuzz beneath, on seedlings and young plants
Downy mildew in damp, crowded conditions
Thin seedlings promptly to 10 cm, remove affected leaves, and avoid overhead watering in the evening.
Leaves and young shoots eaten on new plantings in autumn and mild winter spells
Slugs and snails
Clear fallen leaves from round the plants, check at dusk, and use nematodes while the soil is still above 5 °C.
Pruning
Pruning and care
Pinch tips in Jul for bushy plants. Deadhead through Apr to May, then pull bedding types after flowering to make room for summer plants. Perennial 'Bowles's Mauve' is trimmed lightly after each flush and replaced after 3 to 4 years as it goes woody. No staking; fully hardy, but firm back any plants lifted by frost in Jan.
Good to knowClassic spring bedding with tulips; lift after flowering.
Growing wallflowers in pots
Wallflowers suit a 30 cm pot, about 12 litres, for a spring display: plant five in October in peat-free multipurpose or loam-based compost with a fifth of grit, with tulip bulbs set beneath them. Fresh compost carries them to February with no feed. Stand the pot in full sun near a door or path where the scent will be noticed, raise it on feet, and water only when the compost is dry during winter. Compact series such as 'Sugar Rush' are the best fit for window boxes at 20 cm apart. Empty the pot after flowering in May.
Wallflowers: common questions
When should I plant wallflowers?
Plant wallflowers in September or October so they root before winter. Bare-root bundles appear in garden centres and markets in October and should be planted the day you buy them, firmed in hard and watered. Planted later than October they have little time to establish and flower poorly.
Do wallflowers come back every year?
Bedding wallflowers are biennials and are pulled up after flowering in May, although on a dry wall or in poor, limy soil a few will live and flower for another year or two. Perennial wallflowers such as 'Bowles's Mauve' last three to four years before going woody and are renewed from cuttings taken in July or August.
Can I grow wallflowers from seed?
Yes, and it is easy. Sow in May or June in a seedbed outdoors, 1 cm deep, thin to 10 cm, pinch out the tips at 15 cm and move the plants to their flowering positions in September or October. Home-raised plants moved with soil on their roots establish better than bought bare-root ones.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.
- Erysimum cheiriRHS
- Club rootRHS
- How to grow wallflowersBBC Gardeners' World