Greater wood-rush

Greater wood-rush: how do you recognise it?

Habit

Dense, slightly arching clumps 30 cm tall, with flower stems to 40 cm; spreads slowly by short runners.

Leaves

Broadly strap-shaped, up to 2 cm wide, glossy dark green, with long white hairs along the edge; evergreen.

Flowers

Loose panicles of small, chestnut-brown flowers in April–June, on thin stems above the leaves.

Family

Rush family (Juncaceae): not a true grass, although it looks very much like one.

Roots

Fibrous and dense, with short runners; forms a firm mat.

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

Why grow it?

• Evergreen: a fresh, glossy green carpet even in winter.
• Grows in dry shade under trees, where lawn and most plants give up.
• Quickly knits into a dense mat that smothers weeds.
• Native and at home in a woodland or wildlife garden.
• Hardly any work: no pruning, no feeding and little water once established.

Greater wood-rush: where does it grow best?

• Part shade to shade; in full sun the leaves scorch in dry weather.
• Humus-rich soil: sand, loam or peat, acid to neutral. Avoid chalky soil.
• Moist but not wet soil is ideal, but once established it also copes with dry shade under trees.
• Plant 40 cm apart, about 6 plants per m²; it then knits together in one or two years.

Light

Partial shade and shade

Soil type

Sand, loam or peat

Acidity

Acid or neutral

Moisture

Normal

Size

0.4 m tall, 0.5 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Wood anemone: White spring flowers that come up between the clumps, also native.
• Male fern: Fine, airy fronds beside the broad, glossy leaves of the wood-rush.
• Barrenwort: Also evergreen and tough in dry shade.
• Foxglove: Tall flower spikes above the low mat, in the same light woodland soil.

Greater wood-rush: when and how to plant it?

Plant in March–May and September–October.

1. Plant in March–May or in September–October; under trees autumn is ideal because there is more rain.
2. Loosen the soil and work in a few spadefuls of leaf mould, especially between tree roots.
3. Dig a hole slightly larger than the root ball and set the plant at the same depth as it was in the pot.
4. Plant 40 cm apart in a staggered pattern so the clumps quickly form a closed mat.
5. Water well after planting and in dry spells during the first year, as tree roots compete for water.
6. Mulch with leaf mould or shredded leaves.

Care

Water

Regularly in dry spells during the first year. After that only in long droughts under trees.

Feeding

Not needed; a thin layer of leaf mould in spring is enough.

Fallen leaves

A thin layer of fallen leaves can stay and rots down into humus. Rake off thick layers so the clumps are not smothered.

Tidying

In March, comb or pull brown and dead leaves out of the clumps.

Spent flowers

Cut off the brown flower stems in July if they look untidy, or simply leave them.

Tip: Plant 40 cm apart in a staggered pattern and water faithfully in dry spells during the first year: after that it copes even among tree roots and quickly forms a green mat.

Greater wood-rush: when to prune it?

Pruning months: March and July.

When: Evergreen: it is not cut back, only tidied in March and, if you like, after flowering in July.

How:

• In March, comb dead and brown leaves out of the clumps with your fingers or a small rake.
• Cut damaged leaves off at the base.
• In July, cut off the spent flower stems if you do not like them.
• If old clumps go bare in the middle, rejuvenate them by dividing.

Caution: Do not cut it short every year like a deciduous grass: you would lose the green winter foliage.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April or September, lift a clump, split it with a spade and replant straight away.

Runners

Detach young rosettes from the edge with some roots and plant them elsewhere or pot them up.

Seed

It sometimes self-seeds; move the seedlings in spring. Cultivars do not always come true from seed.

Greater wood-rush: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy to about −25 °C: no protection is needed in Belgium.
• The leaves stay green all winter; after hard frost the tips may brown, cut them off in March.
• Rake thick layers of fallen leaves off the clumps so they are not smothered.
• In a pot: stand it in shade against a wall and do not let the compost dry out.

Diseases and pests

• Brown leaf tips: From drought, full sun or hard frost. Water in dry spells, choose a shady spot and cut off brown leaves in March.
• Bare patches: Old clumps die out in the middle. Rejuvenate them by dividing.
• Yellow leaves: On chalky or heavy, waterlogged soil. Move it to humus-rich, acid to neutral soil.
• Smothering: Under a thick layer of fallen leaves the foliage rots. Rake thick layers off in November.

Through the year

• January: Green winter foliage in the shade garden.
• March: Comb out dead and brown leaves. Plant and divide. Add leaf mould.
• April: Flowering begins. Plant.
• May: Flowering. Water young plants in dry spells.
• June: Last flowers.
• July: Cut off spent flower stems.
• August: Water in long dry spells.
• September: Plant and divide.
• October: Plant, ideal under trees.
• November: Rake thick layers of fallen leaves off the clumps.

Did you know?

• Wood-rushes are recognised by the long white hairs along the leaf edge; true rushes have round, hairless stems and leaves.
• According to the usual explanation, the name Luzula comes from the Italian ‘lucciola’ (glow-worm), because the dewy hairs glisten.
• In oak woods on acid soil in Britain and Ireland it sometimes covers whole slopes with a dense green carpet.