Japanese spurge

Japanese spurge: how do you recognise it?

Habit

Low, upright stems of 20–25 cm that spread by underground runners into a dense carpet.

Leaves

Obovate, 5–10 cm long, leathery and glossy dark green, coarsely toothed towards the tip, in whorls at the top of the stems.

Flowers

Short white spikes at the stem tips in April–May: male flowers with thick stamens at the top, a few female flowers at the base.

Roots

Shallow roots and runners just below the surface, which widen the carpet a little every year.

Growth

Slow in the first year; after 2–3 years a planting of 8–10 plants per m² usually closes into a carpet.

Flowering: April–May · Plants: March–April and September–October · Pruning: March

Why grow it?

• An evergreen carpet that stays fresh and glossy green all year round.
• Grows in deep shade under trees and between shrubs, where little else will grow.
• Once closed, the carpet keeps weeds out and needs hardly any work.
• Keeps the soil under trees and on shady banks covered, so it dries out and washes away less.
• Short white flower spikes above the dark foliage in spring.

Japanese spurge: where does it grow best?

• Partial to deep shade; in full sun the leaves turn yellow and scorch.
• Humus-rich sandy or loamy soil, acid to neutral: on chalky soil the leaves turn yellow.
• Soil that stays moist but not waterlogged; under trees a mulch of leaf mould helps a lot.
• Plant 8–10 plants per m², about 30–35 cm apart.

Light

Partial shade and shade

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

0.25 m tall, 0.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Rhododendron: Also likes acid, humus-rich soil and shade; the carpet covers its base.
• Hydrangea: A flowering shrub above the green carpet.
• Ferns: Taller, airy fronds that rise above the carpet.
• Hosta: Large leaves as an accent among the finer greenery.
• Snowdrop: A touch of white in February in the green carpet.

Japanese spurge: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October, when the soil is neither frozen nor bone dry.
2. Loosen the soil and work in plenty of leaf mould or well-rotted compost, especially under trees.
3. Set out 8–10 plants per m² in a staggered pattern so the carpet closes sooner.
4. Plant at the same depth as in the pot and firm the soil well.
5. Water in thoroughly straight away, even if it is raining.
6. Mulch between the young plants with leaf mould or fine wood chips to keep weeds down.

Care

Watering

In the first year during dry spells, until the carpet has closed. Under trees, also later in dry summers.

Feeding

Some compost or leaf mould in spring. Chemical fertiliser is not needed.

Weeding

Weed between the young plants for the first two years; after that the carpet keeps weeds out itself.

Mulching

A layer of leaf mould in spring keeps the soil loose, rich in humus and moist.

Fallen leaves

Leave autumn leaves from trees where they fall: they rot down into humus. Only remove thick, wet mats.

Tip: Plant 8–10 per m² in humus-rich, lime-free soil and be patient: in the first year little seems to happen, then the carpet closes quickly.

Japanese spurge: when to prune it?

Pruning months: March.

When: Pruning is not needed. If an old planting becomes bare or untidy, cut or mow it short in March.

How:

• In March, cut or mow a bare planting back to 5–10 cm: it soon regrows thick and dense.
• Cut out dead or diseased stems back to healthy green growth.
• Chop off runners that creep beyond the bed with a spade.

Caution: Cut diseased stems in dry weather and clear them away at once, so the fungus does not spread further.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In spring or autumn: dig out pieces of the carpet with roots and runners and replant them straight away.

Cuttings

In June–August: 10 cm stem cuttings, lower leaves removed, in moist cutting compost in a shady spot. They root within a few weeks.

Japanese spurge: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C, and the leaves stay green all winter.
• In hard frost with bright winter sun some leaves may turn brown; new leaves soon follow in spring.
• No protection is needed: fallen tree leaves between the stems make a natural blanket.

Diseases and pests

• Stem blight: Brown leaf spots and darkening stems, after which patches of the carpet die, mainly in dense, damp plantings. Cut out affected parts, thin the planting and improve air flow.
• Yellow leaves: Too much sun or too chalky a soil. Move it to more shade and mulch with leaf mould.
• Slow start: In the first year it makes little growth above ground. Water in dry spells and mulch; after 2–3 years the carpet closes.
• Drying out: Under trees with many roots the soil dries out quickly. Water generously in dry summers and mulch every spring.

Through the year

• March: Cut or mow a bare or untidy planting short. Planting.
• April: Flowering. Planting. Apply leaf mould.
• May: Last flowers. Weed between young plants.
• June: Take cuttings.
• July: Water during dry spells, especially under trees.
• August: Take cuttings. Water during dry spells.
• September: Planting and dividing.
• October: Planting. Leave fallen leaves in place.
• December: Evergreen carpet. Nothing to do.

Edible and useful

Not edible. All parts of Japanese spurge are poisonous: it belongs to the box family and, like box, contains alkaloids that cause vomiting, stomach ache and diarrhoea if eaten. Its evergreen leaves stay in winter, when there is little other greenery: never give it to rabbits, guinea pigs, goats or sheep, and do not throw trimmings or dug-out pieces into a field, run or hutch. Do not let children eat it, keep an eye on dogs and cats, and wear gloves if you cut back or dig out large amounts. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Did you know?

• Japanese spurge belongs to the same family as box, the Buxaceae.
• The name Pachysandra comes from the Greek pachys (thick) and andros (man), after the strikingly thick stamens of the male flowers.
• On a single flower spike, the male flowers are at the top and the female flowers at the base.