Japanese anemone

Japanese anemone: how do you recognise it?

Habit

A low clump of leaves with branching flower stems up to 1.2 m above it; the clump grows about 60 cm wide and spreads by runners.

Leaves

Large, divided into three and lobed, rather like vine leaves; dark green and slightly hairy.

Flower

Saucer-shaped, 5–8 cm, single or semi-double, with a green centre and a ring of yellow stamens.

Colour

White or soft to deep pink.

Roots

Thick, fleshy roots and underground runners; a piece of root can grow into a new plant.

Flowering: August–October · Plants: March–May · Pruning: March

Why grow it?

• It flowers late, from August to October, when many other perennials have finished.
• One of the few tall flowering plants for partial shade.
• Bees and bumblebees find pollen in the open flowers in late summer.
• Tough and long-lived: once established it needs hardly any care.
• The round seed heads, which turn woolly after flowering, are decorative too.

Japanese anemone: where does it grow best?

• Partial shade or sun; full sun only if the soil does not dry out in summer.
• Humus-rich loam or clay, moisture-retentive but well-drained; acid, neutral or chalky is fine.
• Normally moist: drought gives brown leaf edges, wet soil in winter makes the roots rot.
• Sheltered from strong wind, as the tall stems can snap.
• Allow 50–60 cm between plants and give it room to spread.

Light

Sun and partial shade

Soil type

Loam or clay

Acidity

Not fussy

Moisture

Normal

Size

1.2 m tall, 0.6 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Autumn aster: Flowers at the same time and fills the late-summer border with purple and blue.
• Ornamental grasses: Airy stems that are at their best at the same time as the anemone.
• Hydrangea: A shrub that flowers from summer to autumn in the same partial shade.
• Ferns: Green structure at its feet in a shady corner.
• Hosta: Large leaves as a calm base in partial shade.

Japanese anemone: when and how to plant it?

Plant in March–May.

1. Plant in March, April or May: that gives it a whole season to root before winter.
2. Dig a hole twice as wide as the pot and mix in compost.
3. Set the plant at the same depth as in the pot and firm the soil.
4. Space plants 50–60 cm apart, keeping in mind that it spreads.
5. Water well straight away and keep the soil moist in the first year.
6. Spread a mulch of leaf mould around the plant.

Care

Watering

Regularly in the first year, then in long dry spells. Drooping leaves mean it is thirsty.

Feeding

A layer of compost in spring is enough.

Mulching

A layer of leaf mould in spring keeps the soil cool and moist.

Support

In a windy spot the tall stems may need support.

Spreading

In spring, dig out runners that go too far.

Tip: Plant in spring and be patient: it grows slowly in the first year, then spreads freely. Give it a spot where it is allowed to spread, or dig out the runners every spring.

Japanese anemone: when to prune it?

Pruning months: March.

When: In March, before the new shoots appear. Leave the stems standing in autumn.

How:

• In March, cut the old, dry stems down to just above the ground.
• Do not cut spent flower stems in autumn: they protect the crown and the seed heads are attractive.
• In summer, simply remove yellow or damaged leaves.

Caution: Wear gloves: the sap can irritate the skin.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Root cuttings

In December–February: dig up a piece of thick root, cut it into pieces about 5 cm long and lay them in a tray of sandy compost, just covered. They sprout in spring.

Runners

In spring, dig up a young shoot with roots at the edge of the clump and replant it elsewhere straight away.

Division

Large clumps can be divided in spring, although they are slow to recover.

Japanese anemone: how does it get through the winter?

Hardy to −25 °C.

• Hardy to about −25 °C: in most Belgian winters no protection is needed.
• Give young plants a layer of leaf or compost mulch in their first winter.
• Leave the stems until spring; they protect the crown.
• Wet soil in winter is more dangerous than frost.

Diseases and pests

• Spreading too far: On light, moist soil it spreads vigorously. Dig out runners in spring; every forgotten bit of root can sprout again.
• Slow start: In the first year it hardly seems to grow. Be patient: from the second or third year it gets going.
• Leaf nematodes: Brown, angular patches between the veins, mostly on lower leaves. Remove affected leaves and dispose of them.
• Slugs: They eat the young shoots in spring. Pick them off in the evening.
• Drought damage: Brown, dried-out leaf edges in summer. Water and mulch the soil.

Through the year

• January: Take root cuttings.
• March: Cut down old stems. Add compost or mulch.
• April: Plant. Dig out runners or divide.
• May: Plant. Watch for slugs.
• June: Water in dry spells.
• July: Support the tall stems if needed.
• August: Flowering begins.
• September: Full flower: pollen for bees and bumblebees.
• October: Last flowers. Leave the stems standing.
• December: Take root cuttings.

Edible and useful

Not edible. All parts of these garden anemones are poisonous: when the plant is damaged it releases protoanemonin, an acrid compound also found in buttercups. In the mouth it causes a burning feeling, drooling, vomiting and stomach ache, in children as well as in dogs, cats, rabbits and guinea pigs; on the skin, redness, itching and sometimes small blisters. The acrid taste puts most people and animals off, but do not plant them in a run, and do not throw trimmings or dug-out pieces into a field, run or hutch. They spread by rhizomes: wear gloves when chopping them back, cutting down and dividing, and wash your hands afterwards. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Despite the name Japanese anemone, its parents come from China and the Himalaya; one of them had long been grown in Japan and became known in Europe from there.
• The white variety ‘Honorine Jobert’ was found in France as early as the 19th century and is still one of the most popular.
• A small piece of root can grow into a whole new plant; that is why it often reappears where you removed it.