Wood avens

How to recognise it

Habit

Loose perennial of 20–60 cm, with a basal rosette of leaves and branched, hairy flowering stems.

Leaf

Rosette leaves pinnate, with a few small side lobes and a large, rounded or three-lobed end lobe. Stem leaves three-lobed, with strikingly large, leaf-like stipules at the base.

Flower

Small and yellow, 1–1.5 cm, with five spreading petals and green sepals that fold back after flowering. The flowers face upwards.

Fruit/Seed

A ball of about 1.5 cm made of hairy nutlets, each ending in a bent hook: a real bur.

Roots

Short, thick rootstock that smells of cloves when broken.

Confusion with

Water avens has nodding, orange-pink bells and grows in wetter places; the two sometimes hybridise. Buttercups have glossy petals, no large stipules and no hooked fruits.

Flowering: May–August · Pruning: August

Why grow it?

• Flowers from May into August in shady spots where few other wild flowers manage.
• Small bees, hoverflies and flies visit it for nectar and pollen.
• Its hooked seed heads travel in the fur of foxes, deer and dogs: a fine example of seed dispersal by animals.
• Keeps a green rosette of leaves through winter, covering the ground under shrubs and hedges.
• The clove-scented root was once used to flavour beer and wine and to scent linen.
• An easy native filler for a shady wildlife garden or a hedge bottom.

Wood avens: where does it grow best?

• In the wild: deciduous woods, woodland edges, hedges, wooded banks, parks and rough ground, often on nutrient-rich soil.
• In the garden: partial to full shade, under shrubs, along a hedge or on the north side of the house.
• Moist to damp, humus-rich soil; sand, loam or clay are all fine.
• It also grows in full sun, but then needs more water and stays smaller.

Goes well with

• Red campion: Pink flowers in May–June in the same partly shaded spots.
• Herb Robert: Small pink flower that also self-seeds in shade and flowers for a long time.
• Garlic mustard: White flowers in April and food plant of the orange-tip butterfly, ideal for a hedge bottom.
• Male fern: Green, sturdy foliage as a backdrop in the shade.
• Wood anemone: Flowers in March–April, before the avens gets going.

Wood avens: when and how to plant it?

1. Buy plants or seed from a native plant nursery. Never dig plants up from the wild.
2. Sow outdoors in September–October, in pots or directly on bare ground, pressing the seed in lightly; winter cold helps germination.
3. Plant pot-grown plants in March–April or in October, 30–40 cm apart.
4. Water well when planting and keep the soil moist for the first few weeks.
5. Then let nature take its course: after a year or two it self-seeds and you will find seedlings nearby.

Care

Water

Only in the first year during dry spells. After that it copes, even in dry summers in the shade.

Feeding

Not needed. On rich soil it grows tall and floppy; a little leaf mould in autumn is plenty.

Letting it seed

Let some seed heads ripen if you want it to spread.

Spreading

For fewer seedlings, cut off the faded stems in July–August, before the burs are ripe.

Weeding

Pull out unwanted seedlings while they are small; older plants have a sturdy rootstock.

Tip: If you want wood avens without burs in your dog’s coat, cut the faded stems in August and leave only a few at the back of the hedge bottom.

Pruning and mowing

Pruning months: August.

When: After flowering, in August, if you want to limit self-seeding; otherwise only in early spring.

How:

• Cut the flowering stems back to just above the leaf rosette.
• In a wildlife garden, leave a few stems with seed for new plants.
• The rosette itself needs no cutting: it stays green in winter.
• In March, remove old brown leaves if you prefer a tidier look.

Caution: Do not wear a woollen jumper when cutting the ripe seed heads: the hooks get stuck and are hard to remove.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow ripe seed in September–October in a pot of seed compost and leave it outside over winter. The seeds germinate in spring.

Division

In March or October, lift a plant and split the rootstock with a spade into pieces, each with a few leaves.

Wood avens: how does it get through the winter?

Hardy to −30 °C.

• The leaf rosette usually stays green and covers the ground under hedges and shrubs.
• Fully hardy: hard frost does not harm it.
• Together with fallen leaves, the rosette forms a sheltered litter layer for small soil creatures.

Diseases and pests

• Too many seedlings: It self-seeds easily in borders and between paving. Cut the stems after flowering and pull out young seedlings straight away.
• Burs: The hooked fruits get caught in the fur of dogs and cats. Cut them off along paths where your pets walk.
• Powdery mildew: White powder on the leaves in dry summers. Harmless; cut off the worst leaves and water a little.
• Hard to pull out: Older plants snap off above the rootstock and regrow. Lift them with a narrow spade or a weeding knife.

Through the year

• March: New leaves. Plant or divide.
• April: Plant. The rosettes fill out.
• May: First small yellow flowers.
• June: Full flower. Visits from hoverflies and small bees.
• July: Flowering and the first burs.
• August: Last flowers. Cut faded stems if you want fewer seedlings.
• September: Harvest ripe seed and sow it straight away.
• October: Sow, plant or divide.
• November: Leaf mould around the plants. The rosette stays green.
• December: Rest. Green rosette in winter.

Did you know?

• The root smells of cloves because it contains eugenol, the same scent compound as in real cloves; the Dutch name nagelkruid means ‘clove herb’.
• Its old Latin name herba benedicta, ‘blessed herb’, lives on in the French benoîte and the old English name herb bennet: people once believed the plant kept evil spirits away.
• Urbanum means ‘of the town’: the plant likes to grow close to people, in parks, gardens and along paths.