Cowslip

Cowslip: how do you recognise it?

Habit

Low leaf rosette about 20 cm wide, with flower stems 15–20 cm tall.

Leaves

Oval, wrinkled and softly hairy, 5–15 cm long, in a flat rosette.

Flower

A one-sided cluster of nodding, tubular flowers on a single stem, in April and May.

Colour

Golden yellow with an orange spot at the base of each petal, in a pale green calyx.

Scent

Soft and sweet, especially on a sunny day.

Seed

Small capsules inside the inflated calyx; the seed ripens in June–July.

Flowering: April–May · Harvest and fruit: March–May · Sowing: September–October · Plants: March–April and September–October

Why grow it?

• An early spring flower for bumblebees, bees and bee-flies.
• Native: perfect for a wildlife garden or a wildflower meadow.
• Softly scented flowers in April and May.
• Self-seeds and forms lovely groups after a few years.
• Young leaves and flowers are edible, for example as a garnish in a salad.
• Tolerates sun and fairly dry soil, where the primrose struggles.

Cowslip: where does it grow best?

• Sun to partial shade; in sun it stays compact and flowers freely.
• Loam or clay, neutral to chalky; poor soil is better than very rich soil.
• Normal to fairly dry; it dislikes wet soil in winter.
• Plant 20 cm apart, in small groups or scattered through grass.

Light

Sun and partial shade

Soil type

Loam or clay

Acidity

Neutral or chalky

Moisture

Dry or normal

Size

0.2 m tall, 0.2 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Wild daffodil: Flowers around the same time and suits the same meadow.
• Oxeye daisy: Takes over the flowering in May and June.
• Salad burnet: A chalk-loving meadow plant with fine, decorative leaves.
• Wild marjoram: Summer flowers for butterflies and bees on the same dry, chalky soil.
• Bird’s-foot trefoil: Yellow flowers in summer and a food plant for the common blue butterfly.

Cowslip: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or September–October; sow outdoors in September–October.
2. Loosen the soil; in grass, cut out a turf of 20 × 20 cm.
3. Set the plant at the same depth as in the pot, with the centre of the rosette at soil level.
4. Leave 20 cm between plants or set them in loose groups.
5. Water straight away and keep the soil moist for the first few weeks.
6. Do not feed: in poor soil the grass has less chance to take over.

Care

Water

Only after planting and during long dry spells in spring.

Feeding

Not needed. A poor, chalky soil is ideal.

Mowing

In a meadow, mow only after the seed has set, from late June or in July. Leave the cuttings for a few days so the seed drops, then remove them.

Spent flowers

Leave them: it will self-seed.

Dividing

Large clumps can be divided every few years after flowering.

Tip: Sow outdoors in autumn: the seed needs cold to germinate. In a meadow, mow only after the seed has set, from late June.

Cowslip: when to prune it?

When: No pruning is needed. In a meadow, mow only once the seed is ripe, from late June.

How:

• Leave the spent flower stems until the seed is ripe and brown.
• Mow a meadow with cowslips only after the seed has set, then remove the cuttings.
• In a border, just remove yellow or rotting leaves.

Caution: If you mow as early as May, it sets no seed and disappears from the grass within a few years.

Pruning calendar and basic rules

Propagation

Seed

In September–October, sow fresh seed outdoors, in a pot or where it is to grow, and barely cover it. The seed needs cold and germinates in spring.

Division

After flowering or in September, lift a large clump, split it into pieces each with a rosette and roots, and replant straight away.

Cowslip: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection is needed.
• In winter only a small rosette remains; it grows away quickly in spring.
• The cold is useful: seed sown in autumn only germinates after winter.
• In a pot: make sure the soil does not stay wet.

Diseases and pests

• Slugs: They eat young leaves and flowers. Pick them off in the evening or set a beer trap.
• Vine weevil: The larvae eat the roots, especially of plants in pots. Use nematodes in spring or late summer.
• Swamped by grass: In very rich soil the grass grows too strongly. Do not feed, and always remove the cuttings.
• Rot: Plants that rot away in winter are too wet. Choose a better-drained spot.

Through the year

• March: Plant. New rosettes start to grow.
• April: In flower. Plant.
• May: Full bloom. Do not mow the meadow yet.
• June: The seed ripens. Divide large clumps after flowering.
• July: Mow the meadow once the seed has set; remove the cuttings.
• September: Sow outdoors. Plant and divide.
• October: Sow outdoors. Plant.

Edible and useful

Flowers (April–May)

Pick the fragrant yellow flower clusters in April and May on a dry day, only from plants in your own garden. They smell of honey and apricot. Use them in tea, to decorate salads and cakes, or in cowslip syrup.

Leaves (March–April)

The young leaves in March and April are edible and mild: add a few to a salad or soup.

Storing

Dry the flowers in a thin layer on paper somewhere airy and dark and keep them in a closed jar for up to a year. Fresh, they keep for a day in the fridge.

Caution: In the wild, the cowslip has become scarce in many places: only pick in your own garden, and leave enough flowers to set seed. Do not use the roots. People allergic to aspirin or other salicylates, pregnant women and people on blood thinners should avoid cowslip tea. Do not confuse it with florists’ primulas, which can cause eczema.

Eating and using is at your own risk: see the terms of use.

Recipes

• Cowslip tea (Tea · 1 cup · 10 min)
• Cowslip syrup (Syrup · ± 400 ml · 20 min + overnight steeping)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The Dutch name sleutelbloem, ‘key flower’, refers to the flower cluster, which looks like a bunch of keys. According to legend, Saint Peter dropped the keys of heaven, and cowslips grew where they fell.
• Where cowslips and primroses grow together they sometimes cross naturally. The colourful garden polyanthus are partly descended from such crosses.
• In England, wine used to be made from the flowers: cowslip wine.