Rough chervil

How to recognise it

Habit

Biennial: in the first year a rosette of leaves, in the second year a branched flower stem of 30–100 cm.

Leaf

Two to three times pinnate, with blunt, lobed segments; dull green, hairy on both sides and often tinged with purple.

Flower

Small white flowers in umbels with 6–12 rays, from May to July. In bud the umbels nod; there are no bracts below the umbel, or just one or two.

Fruit/Seed

Narrow, elongated, hairless fruits of 4–7 mm with clear ridges, tapering towards the tip.

Stem

Solid, roughly hairy, purple-spotted or entirely purple, and clearly swollen below the joints.

Look-alikes

Cow parsley flowers earlier (April–June), has fresh green, more finely divided leaves and a green, grooved, unspotted stem that is almost hairless higher up. Hemlock has a hairless, bluish-bloomed stem with purple blotches, an unpleasant mousy smell and is highly poisonous. Upright hedge-parsley flowers later, in July–August, and has fruits covered in hooked bristles.

Flowering: May–July · Pruning: September

Why grow it?

• White umbels in June–July full of flies, hoverflies, beetles and small wasps: a busy meeting place for insects.
• It flowers between cow parsley and upright hedge-parsley, so the hedge stays white from April to August.
• A typical plant of flowery hedgerows and wooded banks, where this biennial self-seeds.
• The dry stems and umbels give shelter to small insects and spiders in winter.
• A good practice plant for learning to tell umbellifers apart, and so to keep poisonous and edible species separate.

Rough chervil: where does it grow best?

• In the wild along hedgerows, wooded banks, woodland edges, sunken lanes and shady verges.
• Partial to light shade; you see it less often in full sun.
• Rich soil that is not too dry, especially loam and clay.
• In the garden at the edge of a hedge or shrubbery, in a wild corner where it may self-seed, well away from the vegetable plot.

Goes well with

• Garlic mustard: Flowers in April–May in the same hedge and is a food plant of the orange-tip.
• Red campion: Pink flowers from May to July, a lovely contrast with the white umbels.
• Herb-Robert: Small, pink, long-flowering plant for the shady edge below.
• Wood avens: Small yellow flowers and hooked fruits in the same shady margin.
• Hawthorn: The hedge itself: blossom in May and berries for birds in autumn.

Rough chervil: when and how to plant it?

1. Never dig up plants in the wild: buy seed from a seed supplier specialising in native plants.
2. Choose a spot at the edge of a hedge or wooded bank, away from the vegetable plot and from places where young children play.
3. Sow in September–October, soon after the seed ripens: it needs a cold spell and only germinates in spring.
4. Scatter the seed on loosened, open soil and rake it in lightly; thin later to 30–40 cm.
5. In the first year you only see a rosette of leaves; flowering comes in the second year. No watering is needed.
6. Wear gloves when collecting seed or removing plants, and wash your hands afterwards.

Care

Water

Not needed.

Feeding

Not needed; the rich soil at the foot of a hedge is enough.

Let it seed

Let some plants set seed every year, otherwise this biennial will disappear.

Spreading

It can self-seed freely. Pull out surplus rosettes in spring, wearing gloves, or cut off the umbels before the seed is ripe.

Mowing

Mow a hedge margin or verge once a year, in September after the seed has dropped, and remove the cuttings.

Tip: Learn to recognise rough chervil by its purple-spotted, roughly hairy stem with swollen joints: that way you can tell it straight away in June from the earlier-flowering cow parsley.

Pruning and mowing

Pruning months: September.

When: In September, once the seed has dropped. Some of the stems can stay standing until spring.

How:

• Mow or cut down the dead plants after the seed has fallen and take them away.
• Leave some of the dry stems standing as winter shelter for insects.
• If you want fewer seedlings, cut off the umbels soon after flowering, before the fruits ripen.
• Wear gloves and wash your hands afterwards.

Caution: Do not feed the cuttings to rabbits, guinea pigs or other animals, and do not leave them in a field.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

The only way: sow fresh seed outdoors in September–October. It germinates after winter, forms a rosette and flowers the following year.

Self-seeding

In a suitable spot it keeps itself going by self-seeding; leave a few open patches in the margin for this.

Rough chervil: how does it get through the winter?

Hardy to −25 °C.

• Young rosettes overwinter flat on the ground; plants that have flowered die once they have set seed.
• Fully hardy, to about −25 °C.
• The dry stems and umbels stay standing for a while and give shelter to insects.

Diseases and pests

• Toxicity: All parts are poisonous. Do not sow it where children play or where you pick herbs.
• Mistakes when foraging: Anyone picking wild chervil or cow parsley can get it wrong. Never pick wild umbellifers for the kitchen unless you are certain of the species.
• Too many seedlings: On rich soil it can become plentiful. Cut off the umbels before the seed is ripe.
• Aphids: On young umbels in May–June. Ladybirds and hoverfly larvae clear them up.
• Overgrown by nettles: In a dense stand of nettles it disappears. Mow every year and remove the cuttings.

Through the year

• March: The rosettes grow. Pull out surplus rosettes, wearing gloves.
• April: The flower stems shoot up.
• May: First umbels; the buds nod.
• June: Full flower. Flies, beetles and hoverflies on the umbels.
• July: Last flowers; the fruits ripen.
• August: The seed is ripe and drops. Cut off umbels if you want fewer seedlings.
• September: Mow and remove dead plants. Sow.
• October: Sow on open soil.
• December: Rest. The dry stems give shelter.

Did you know?

• Temulum comes from the Latin temulentus, drunk: the plant was once linked to staggering and dizziness after eating it. The Dutch name, dolle kervel or mad chervil, refers to the same thing.
• The genus name Chaerophyllum comes from the Greek chairephyllon, the old name for chervil, meaning pleasant leaf.
• In the hedge, three white umbellifers flower one after another: cow parsley in April–May, rough chervil in June and upright hedge-parsley in July–August.