Wood spurge

Wood spurge: how do you recognise it?

Habit

Clump of upright, unbranched stems, 40–60 cm tall and about 45 cm wide.

Leaves

Narrowly oval to lance-shaped, up to 8 cm long, dark green and often flushed red; evergreen and set closely in a spiral around the stem.

Flowers

Lime-green heads of tiny flowers, surrounded by cup-shaped bracts fused in pairs, from March to May.

Stems

Biennial: a stem makes leaves in its first year, flowers the following spring and then dies.

Sap

All parts contain a white milky sap that irritates skin and eyes.

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

Why grow it?

• Evergreen foliage: there is something to see in the shade border even in December and January.
• Early, fresh lime-green flowers from March to May that combine well with spring bulbs.
• One of the few plants that do well in dry shade under trees and among tree roots.
• Native, and an early source of nectar for bees and hoverflies.
• Slugs and rabbits usually leave it alone, thanks to its bitter milky sap.

Wood spurge: where does it grow best?

• Partial or full shade, for example under deciduous trees or on the north side of a hedge; full sun is too hot for it.
• Sand, loam or clay, acid, neutral or chalky: it is not fussy, as long as the soil drains well.
• Dry to normal soil; once established it copes well with drought, but not with waterlogging in winter.
• Allow 40–45 cm between plants; it looks best in groups of three to five.
• If you choose the variety robbiae, give it room or a contained spot: it spreads vigorously.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

0.6 m tall, 0.45 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Hellebore: Flowers in winter and early spring in the same shade; together an evergreen pair.
• Barrenwort: Also tough in dry shade, with dainty flowers in April and handsome leaves.
• Ferns: Their fine fronds contrast with the sturdy clumps of the spurge.
• Wood anemone: White spring flowers under trees, beside the lime-green heads.
• Siberian bugloss: Sky-blue flowers in April, lovely next to the lime green.

Wood spurge: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or September–October, when the soil is neither frozen nor waterlogged.
2. Wear gloves: damaged stems or roots release an irritant milky sap.
3. Dig a hole twice as wide as the root ball; under trees, work in a little compost or leaf mould.
4. Set the plant at the same depth as it was in its pot, firm the soil well and space plants 40–45 cm apart.
5. Water in well straight away and keep the soil moist during dry spells in the first year.
6. Spread a layer of leaf mould around the base.

Care

Watering

Weekly in dry weather during the first year. After that it manages on its own, even in dry shade.

Feeding

Not needed. A thin layer of compost or leaf mould in spring is enough; rich soil gives floppy stems.

Mulching

Leave fallen leaves under the trees or add leaf mould, as in a wood.

Spent stems

Cut them off at the base in June–July; the young, non-flowering stems will flower next spring.

Seedlings

It seeds itself a little. Keep the seedlings where you want them and weed out the rest while they are small.

Tip: After flowering, cut out only the stems that have flowered, never the young leafy stems. That way you have a full clump with new flowers every spring.

Wood spurge: when to prune it?

Pruning months: June–July.

When: In June–July, after flowering, when the flower heads fade.

How:

• Cut the flowered stems right down to the base: they die after flowering anyway.
• Leave the young, leafy stems without flowers: they carry next year’s flowers.
• In spring, remove damaged or dead stems.
• Wear gloves and preferably eye protection, then wash your hands and your secateurs.

Caution: Sap sometimes spurts from a fresh cut. Keep your hands away from your eyes and mouth until you have washed them.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April or September: cut off a rooted piece from the edge of the clump and replant it straight away. Very easy, especially with robbiae.

Cuttings

In April–May, take 8–10 cm cuttings from young shoots at the base. Dip the cut end briefly in lukewarm water to stop the sap and insert in sandy cutting compost.

Seed

Sow ripe seed straight away in summer in a pot outdoors, or grow on the self-sown seedlings around the plant.

Wood spurge: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C: in a normal Belgian winter it needs no protection.
• The leaves stay green and often turn a deeper red or purple in the cold.
• Wet soil in winter is more dangerous than frost: make sure drainage is good.
• In a pot: in a severe winter, move it against a wall and wrap the pot in hessian.

Diseases and pests

• Powdery mildew: White powder on the leaves, especially on ‘Purpurea’ and in dry, still air. Cut out affected stems and give the plant more space.
• Root rot: Yellow, limp stems and a rotting base in wet soil. Move it to a better-drained spot.
• Aphids: Sometimes on young shoots in spring. Hose them off; ladybirds will deal with the rest.
• Bare, floppy clump: Too much shade or soil that is too rich. Remove spent stems and rejuvenate the clump by dividing it.
• Spreading: Robbiae in particular quickly takes over a large area with its rhizomes. Chop off the runners with a spade every spring.

Through the year

• March: Flowering begins. Plant or divide. Remove dead stems.
• April: Full flower. Plant. Take cuttings from young shoots.
• May: Last flowers. Watch for aphids.
• June: Cut spent stems off at the base.
• July: Remove the last spent stems. Pot up or weed out seedlings.
• August: Water during long dry spells, especially young plants.
• September: Plant or divide.
• October: Plant. Leaf mould around the base.
• December: Evergreen leaves, often flushed red.

Edible and useful

Not edible. All parts of spurges contain a white, milky sap that is poisonous and caustic. On the skin it causes redness, itching and sometimes blisters; in the eyes it is extremely painful and can damage the cornea. Whenever you work on the plant, wear gloves, long sleeves and ideally safety glasses, do not rub your eyes, wash your hands and secateurs afterwards, and teach children not to break off the stems. If sap gets in your eyes, rinse them at once under running lukewarm water for at least a quarter of an hour and see a doctor. Swallowed, it burns the mouth and causes vomiting and stomach ache, in dogs and cats too; horses and livestock fall ill from it: never throw clippings into a field. 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?

• The name amygdaloides means ‘almond-like’: the leaves resemble those of the almond tree.
• What looks like a single flower in a spurge is a cyathium: a little cup of bracts holding one female and several male flowers, without petals.
• The variety robbiae is known in English as ‘Mrs Robb’s bonnet’: according to tradition, a Mrs Robb brought it back from Turkey in the 19th century in a hatbox.