Wallflower

Wallflower: how do you recognise it?

Habit

Upright, branching plant 30–60 cm tall and 25–30 cm wide, slightly woody at the base.

Leaves

Narrow and lance-shaped, 5–10 cm long, dark green; they stay on the plant in winter.

Flowers

Four-petalled flowers of 2–3 cm in dense clusters, in April and May.

Colour

Yellow, orange, red, reddish brown, purple and cream, often with a velvety sheen.

Scent

Sweet and spicy, rather like cloves; strongest on sunny, still days.

Fruit

Long, narrow pods holding the seed, as in other members of the cabbage family.

Flowering: April–May · Sowing: May–June · Plants: September–October · Pruning: July

Why grow it?

• One of the most fragrant spring flowers, ideal near a patio or front door.
• Flowers in April–May, at the same time as tulips.
• Early nectar for bees, bumblebees and the first butterflies.
• Warm, velvety colours that are rare in spring.
• Likes lime and dry conditions: suits stony, poor spots and even old walls.

Wallflower: where does it grow best?

• Full sun for the best flowering and strongest scent.
• Free-draining soil: sand, loam or clay; neutral to chalky. On acid soil, add some lime.
• Dry to normally moist; it dislikes heavy, wet soil in winter.
• A spot sheltered from cold, drying winter winds.
• Plant 25–30 cm apart.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Neutral or chalky

Moisture

Dry or normal

Size

0.5 m tall, 0.3 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Tulip: The classic pairing: wallflowers fill the base and add scent.
• Forget-me-not: Blue next to warm orange and yellow.
• Daisy: A low pink or white edge at the front.
• Pansy: Even more colour in pots and troughs, flowering at the same time.

Wallflower: when and how to plant it?

Plant in September–October.

1. Sow in May–June in a seedbed, in rows 20 cm apart, and cover the seed with 1 cm of soil.
2. In July, move the seedlings to a nursery bed, 15 cm apart, and pinch them out when they are 15 cm tall.
3. Plant out where they are to flower in September–October, with a good root ball, so the roots are disturbed as little as possible.
4. Set the plant at the same depth as before, 25–30 cm apart, and firm in well.
5. Water in straight away; you can plant tulip bulbs between the plants at the same time.

Care

Watering

Seedlings and young plants in dry summer weather; after autumn planting, almost never.

Feeding

Not needed; too much nitrogen gives soft plants that overwinter badly.

Lime

On acid soil, work some lime into the nursery bed and the planting hole in summer.

Deadheading

Cut off spent flower clusters for a tidy plant and slightly longer flowering.

After flowering

Plants are usually cleared in June; to keep them for a second year, leave them in a dry spot.

Tip: Sow in May–June in a seedbed and plant out in September–October where they are to flower. Pinch out the young plant for a bushy shape. It likes lime; poisonous if eaten.

Wallflower: when to prune it?

Pruning months: July.

When: In July, when the young plants are about 15 cm tall, pinch them out. No other pruning is needed.

How:

• Pinch or cut out the tip of each young plant, just above a few leaves: it branches out and becomes a bushy plant.
• Cut off spent flower clusters during flowering.
• No pruning is needed after flowering: plants are usually cleared in June.

Caution: Wear gloves if you have sensitive skin and wash your hands after handling the plant: it is poisonous if eaten.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

In May–June in an outdoor seedbed. Germinates in 1–3 weeks. Transplant in July, plant out in September–October.

Cuttings

In May–June, take 5–8 cm cuttings from non-flowering shoots in sandy cutting compost, to keep a favourite colour.

Wallflower: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Hardy to about −15 °C: it survives most Belgian winters without protection.
• Cold, drying wind and wet soil do more damage than frost itself: choose a sheltered, free-draining spot.
• In hard frost without snow, you can lay fleece over the plants.
• In pots: keep them against a wall, out of the wind, with good drainage.

Diseases and pests

• Clubroot: A soil-borne disease of the cabbage family: the roots swell, the plant wilts and stays small. Do not grow wallflowers where cabbages grew, lime acid soil and do not compost diseased plants.
• Flea beetle: Small round holes in the leaves of seedlings, especially in dry, warm weather. Keep the soil moist and cover the seedbed with fine insect mesh.
• Grey mould: Grey fuzz on leaves and shoots in wet winters. Do not plant too closely and remove affected parts.
• Aphids: On flower buds in spring. Hose them off; ladybirds will do the rest.

Through the year

• March: First buds. Remove fleece once the weather turns milder.
• April: Full flower and scent.
• May: Flowering. Sow in a seedbed.
• June: Sow. Clear spent plants.
• July: Move seedlings to a nursery bed. Pinch out young plants.
• August: Weed the nursery bed and water in dry spells.
• September: Plant out where they are to flower, with tulip bulbs.
• October: Last planting out.

Edible and useful

Not edible. All parts of wallflower are poisonous, especially the seeds: they contain cardiac glycosides, compounds that, like those of foxglove, act on the heart. Swallowing any causes nausea, vomiting and stomach ache, and in larger amounts a slow or irregular heartbeat. Wallflower belongs to the cabbage family, but it is not a vegetable: do not eat the flowers or use them in salads. Keep children, dogs, cats and grazing animals away from the plant and its seed pods, and do not throw spent plants into a field or pen. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The name wallflower comes from its habit of growing on old walls.
• The French name ‘giroflée’ comes from ‘girofle’, clove, after its spicy scent.
• As a member of the cabbage family, the wallflower can catch the same diseases as cabbages, such as clubroot.