Mugwort

How to recognise it

Growth form

Sturdy perennial, 60–150 cm, sometimes up to 2 m, with a woody rhizome; forms large clumps after a few years.

Leaf

Deeply pinnately cut with pointed lobes, 5–10 cm long; dark green and almost hairless above, silvery-white and felted beneath. Mild aromatic smell when crushed.

Flower

Numerous small, egg-shaped heads of 3–4 mm, without ray florets, yellowish to reddish brown, in long, leafy panicles. Flowers in July–September and is wind-pollinated.

Fruit/Seed

Tiny brown achenes without a pappus, in huge numbers; they fall close to the plant or travel with soil and shoes.

Stem

Upright, grooved, often flushed reddish-purple and somewhat woody at the base.

Confusion with

Wormwood is silvery grey on both sides and smells strongly bitter. Tansy has yellow, button-like flower heads and leaves that are green on both sides. Common ragweed, a non-native plant with even more allergenic pollen, has finely cut leaves that are green on both sides and long spikes of green flower heads.

Flowering: July–September · Pruning: March and August

Why grow it?

• An important food plant: many insect species live on it, including caterpillars of pug moths and other moths, aphids, small beetles and gall midges.
• The dead stems and panicles stand all winter: small insects overwinter among them and birds pick out seeds.
• A plant for a rough corner or a natural verge in a large nature garden, where little else grows so easily.
• The leaves were once used as a kitchen herb with fatty dishes such as goose and duck, and sometimes in herb mixtures for beer, before hops became widespread.
• A plant full of folklore: around Midsummer people used to wear girdles of mugwort, and travellers put the leaves in their shoes.

Mugwort: where does it grow best?

• In the wild on verges, waste ground, rubble, railway land, riverbanks and field edges; often close to people.
• Full sun to light half shade.
• Almost any soil, preferably fertile; it tolerates drought but also grows on moist riverbanks.
• In the garden only in a rough spot: at the edge of a large nature garden, by the compost heap or on a wild verge.

Goes well with

• Tansy: Yellow buttons beside the grey-green panicles on a rough, sunny verge.
• Wild carrot: White umbels on the same dry, fertile verge.
• Common nettle: Together a rough corner full of food plants for butterflies and other insects.
• Wild teasel: Tall, sturdy winter stems beside the mugwort, with seed for goldfinches.

Mugwort: when and how to plant it?

1. Mugwort often arrives by itself. If you want to plant it deliberately, buy a plant or seed from a nursery specialising in native plants. Do not dig up plants in the wild.
2. Sow outdoors in autumn or in March–April on bare soil, barely covering the fine seed.
3. Plant in March–April or in October, at least 60 cm from other plants: a clump grows wide.
4. Choose a spot where it cannot seed or spread into a border, for example between a path and a hedge.
5. Water after planting; after that it needs no further care.

Care

Water

Not needed, except after planting. It copes well with dry summers.

Feeding

Never: on rich soil it grows even taller and spreads even faster.

Mowing

On a verge you can mow it once or twice a year. If you mow at the end of July or in August, before the seed is ripe, it self-sows much less.

Spreading

It spreads by rhizomes and above all by seed. Chop off runners at the edge of the clump with a spade and pull up seedlings while they are small.

Letting it seed

Only let the panicles ripen in a rough corner; elsewhere cut them off before the seed is ripe.

Tip: If you want to keep mugwort in the garden without seedlings everywhere, cut off the panicles of most plants in August and let only one or two ripen for the insects and birds.

Pruning and mowing

Pruning months: March and August.

When: In March, cut down the dead stems; in August, if you wish, cut off the flowering panicles to limit self-sowing.

How:

• Leave the dead stems over winter: they shelter overwintering insects.
• In March, cut them down to just above the ground, before the new shoots appear. Lay them on a brush pile so any insects inside can still emerge.
• If you do not want seedlings, cut off the flowering panicles in August, before the seed is ripe.
• In a rough corner, leave a few panicles for the birds and insects in winter.

Caution: If you are prone to hay fever or eczema, wear gloves and long sleeves and avoid working on the plant while it is in flower: it releases a lot of pollen then.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Self-sows freely. Sow in autumn or spring on bare soil; it germinates easily.

Division

In March–April, lift a clump and split it with a spade into pieces each with part of the rhizome.

Mugwort: how does it get through the winter?

Hardy to −30 °C.

• The leaves die back, but the dry, reddish-brown stems with their panicles stand until spring.
• Small insects overwinter among the dead stems, and birds pick seeds from the panicles.
• Fully hardy; as early as February–March the first new leaves appear at the base.

Diseases and pests

• Spreading: On rich soil it spreads quickly by seed and rhizomes. Mow before the seed ripens, pull up seedlings and chop off the edge of the clump.
• Hay fever: Its pollen causes hay fever in many people in July–September. Do not plant it near a patio or a bedroom window.
• Aphids: Mugwort can be covered in aphids, but they are food for ladybirds, hoverflies and tits. Do not control them.
• Hard to dig out: An old clump has a tough, woody rhizome. Dig it out with a spade in spring and remove every piece.

Through the year

• March: Cut down dead stems and lay them on a brush pile. New leaves appear.
• April: Plant or divide clumps. Pull up unwanted seedlings.
• May: Rapid growth. Aphids attract ladybirds.
• June: The stems shoot up. Pick leaves as a kitchen herb, before flowering.
• July: Flowering begins. Pollen and hay fever.
• August: Full flower. Cut off panicles where you do not want seedlings.
• September: Last flowers; the seed ripens.
• October: Plant. Leave the stems standing for winter.
• December: Dead stems and panicles provide winter food and shelter.

Did you know?

• According to folk explanation, the Dutch name bijvoet comes from an old custom: travellers put the leaves in their shoes against tired feet.
• Around Midsummer, on 24 June, people used to wear a girdle of mugwort and then throw it into the fire to ward off bad luck; in some regions the plant was therefore called St John’s girdle.
• Artemisia is named after the Greek goddess Artemis. In Germany mugwort is still the classic herb for roast goose.