Winter-cress

How to recognise it

Growth form

Biennial or short-lived perennial: a leaf rosette in the first year, then one or more sturdy, branched flowering stems of 30–90 cm.

Leaf

Hairless and glossy dark green. The rosette leaves are lyre-shaped, with a large, round to oval end lobe and 2–5 pairs of small side lobes. The stem leaves clasp the stem with two small ear-like lobes.

Flower

Bright yellow, 7–9 mm, with four petals, in dense spikes at the stem tips; the buds stand above the open flowers. Flowers in April–June, sometimes with a few later flowers.

Fruit/Seed

Upright to angled, four-sided pods of 1.5–3 cm with a short beak, full of small brown seeds.

Stem

Hairless, grooved and sturdy, often a little purplish at the base.

Confusion with

Oilseed rape and turnip have blue-green, waxy leaves and larger flowers. Charlock has rough, hairy leaves. Small-flowered winter-cress has smaller flowers and pods pressed against the stem. Great yellow-cress has smaller flowers and short, plump pods.

Flowering: April–June · Pruning: June

Why grow it?

• An early bloomer: in April–May a source of nectar and pollen for bees, bumblebees and hoverflies.
• Food plant for the caterpillars of the orange-tip and of white butterflies, which eat the leaves and young seed pods.
• The leaf rosette stays green all winter: in the past people ate the peppery, slightly bitter leaves in winter as a wild vegetable or in salads.
• A colourful plant for a damp border, a ditch bank or the edge of a pond in the nature garden.
• Quick and easy: it flowers in the spring after sowing and keeps itself going by self-sowing.

Winter-cress: where does it grow best?

• In the wild along ditches, streams and riverbanks, on damp verges, at field edges, on waste ground and in gardens.
• Full sun to half shade.
• Moist to wet, fertile soil: clay, loam or humus-rich sand. It does not tolerate prolonged drought.
• In the garden: at a pond edge or ditch bank, in a damp border or in a flowery vegetable-garden edge.

Goes well with

• Cuckooflower: Flowers at the same time in the same damp spot and is also an orange-tip food plant.
• Ragged-robin: Pink flowers at the edge of a damp meadow in May–June.
• Water forget-me-not: Little blue stars at the water’s edge beside the yellow.
• Meadowsweet: Takes over later in summer with creamy plumes.

Winter-cress: when and how to plant it?

1. Buy seed from a native seed supplier or a plant from a nursery. Do not dig up plants in the wild.
2. Sow outdoors from May to September, directly where it is to grow or in small pots; cover the seed with a thin layer of soil and keep it moist.
3. The young plants form a leaf rosette in the first year and flower the following spring.
4. Plant out or thin to 25–30 cm apart.
5. Water in dry spells, especially in the first year.

Care

Water

Keep the soil moist; at a pond or ditch edge there is no need.

Feeding

Not needed in ordinary garden soil.

Harvesting

In winter and early spring, pick young leaves from the rosette for salads or soup; they taste peppery and slightly bitter.

Spreading

It self-sows easily. After flowering, cut off most stems before the pods burst open.

Letting it seed

Let a few stems ripen to keep it in the garden: as a biennial it has to sow itself again and again.

Tip: Leave a few winter-cress plants in a damp corner and sow a little more each year: you will have a peppery wild vegetable in winter and a yellow magnet for bees and the orange-tip in spring.

Pruning and mowing

Pruning months: June.

When: In June, after flowering: cut off most spent stems and let a few ripen.

How:

• In June, cut most spent stems back to just above the rosette: this limits self-sowing, and the plant often lives another year.
• Leave a few stems until the pods turn brown, so that new plants appear.
• Watch out for orange-tip caterpillars, which sit on the young pods in May–June: leave a few flowering stems alone until they have gone.
• Put the cuttings in a rough corner or on the compost heap.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Collect the brown pods in June–July and sow straight away or in September. It also self-sows on open, moist ground.

Winter-cress: how does it get through the winter?

Hardy to −25 °C.

• The leaf rosette stays green and glossy all winter, even in frost.
• Fully hardy.
• In winter you can harvest young leaves as a wild vegetable.
• In February–March the rosettes start growing again and in April the first flower buds appear.

Diseases and pests

• Flea beetles: Tiny jumping beetles riddle the leaves with holes, especially in dry weather. Keep the soil moist; older plants suffer little.
• Caterpillars: Caterpillars of white butterflies sometimes eat a lot of leaves. Leave them: the plant recovers and the butterflies are welcome.
• Self-sowing: On open ground it can produce many seedlings. Cut off most stems after flowering and weed seedlings while they are small.
• Aphids: Mealy cabbage aphid on the flowering stems. Spray off with water; ladybirds and hoverflies clear them up.
• Bitter leaves: Old leaves and summer leaves are very bitter. Only harvest young leaves in winter and early spring.

Through the year

• January: Harvest young rosette leaves as a winter vegetable.
• March: The rosettes start growing again. Harvest leaves.
• April: Flowering begins: bees and hoverflies on the yellow spikes.
• May: Full flower. The orange-tip lays eggs on the flower stalks.
• June: After flowering, cut off most stems; let a few ripen.
• July: Collect seed from the brown pods.
• August: Sow for flowers next spring.
• September: Sow, or plant out seedlings 25–30 cm apart.
• November: Green rosettes in winter.
• December: Harvest young leaves.

Did you know?

• Its Latin and Dutch names refer to Saint Barbara: around her feast day on 4 December the leaf rosette is still fresh and green, so people could pick leaves from it in the middle of winter.
• Researchers are testing winter-cress as a ‘trap crop’ for the diamondback moth, a pest of cabbages: the moths readily lay their eggs on it, but the caterpillars do not survive on its leaves.
• There are garden forms with double flowers and with yellow-variegated leaves, grown as ornamental plants.