Crevice alumroot

Crevice alumroot: how do you recognise it?

Habit

Low leaf rosette about 30 cm high, with flower stems to 40 cm; 40–45 cm wide.

Leaves

Round to heart-shaped, lobed and toothed, on long stalks; green, purple, bronze or marked with silver; evergreen.

Flowers

Tiny white to pink bells in airy sprays on thin stems, in June–August.

Crown

A short, woody stem that rises out of the soil over the years.

Roots

Fairly shallow and fibrous; they dry out quickly and are a favourite of vine weevil grubs.

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

Why grow it?

• Coloured, evergreen leaves that look good all year, even in winter.
• Small and neat: ideal at the front of a border, along a path or in a pot.
• Airy flower sprays in summer, visited by bees.
• One of the few plants that bring colour to partial shade without relying on flowers.
• The flower stems are pretty in a small posy too.

Crevice alumroot: where does it grow best?

• Partial or light shade; dark-leaved varieties tolerate morning sun, but fierce midday sun scorches the leaves.
• Humus-rich, well-drained loam or clay, acid to chalky.
• Moist: it should not dry out, but must not sit wet in winter.
• Space 30–40 cm apart; for ground cover five to seven plants per m².

Light

Partial shade and shade

Soil type

Loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.4 m tall, 0.45 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Ferns: Fine green beside the round, coloured leaves, in the same partial shade.
• Hosta: Big leaves behind the low rosettes.
• Japanese forest grass: Yellow or green grass clumps that stand out against purple leaves.
• Lady’s mantle: Lime-green froth beside the dark foliage.
• Lenten rose: Also evergreen and lovely in the same shady border.

Crevice alumroot: when and how to plant it?

Plant in March–May and September–October.

1. Plant in March–May or September–October.
2. Work in a few spadefuls of compost or leaf mould; on heavy clay add some coarse sand for drainage too.
3. Set the crown exactly at soil level: the leaf rosette must not be buried.
4. Space plants 30–40 cm apart.
5. Firm in and water; keep the soil moist for the first few weeks.
6. In a pot: use multi-purpose compost with some garden compost and a pot with a drainage hole.

Care

Watering

In dry spells, especially in pots and in the first year. Avoid waterlogging.

Feeding

A little compost in April; in pots, a few liquid feeds over the summer.

Mulching

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

Deadheading

Cut the flower stems off at the base once they have finished.

Rejuvenating

Older plants turn woody and rise out of the soil: lift them in spring and replant deeper, up to the leaf rosette.

Tip: Check every spring whether the crown has grown up out of the soil: if so, lift the plant and replant it deeper, up to the leaf rosette. Watch out for vine weevil too, especially in pots.

Crevice alumroot: when to prune it?

Pruning months: March and August.

When: No real pruning needed. Remove old or damaged leaves in March and cut off spent flower stems in August.

How:

• In March, cut off brown, withered or frost-damaged leaves at the base.
• Leave the healthy evergreen leaves: they protect the heart of the plant.
• Cut spent flower stems off at the base to keep the plant compact.
• If the stem has become long and bare, replant deeper in spring instead of pruning.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In April or September: lift the plant and cut it into pieces, each with a rosette and some roots. Replant them a little deeper than before.

Cuttings

Side rosettes broken off with a piece of stem root in moist cutting compost in a sheltered spot, in spring or summer.

Crevice alumroot: how does it get through the winter?

Hardy to −30 °C.

• Hardy to about −30 °C: no protection is needed in Belgium.
• The leaves stay on through winter and add colour to the border.
• Frost can lift young plants out of the soil: firm them back in spring.
• In a pot: stand it in a sheltered place and make sure excess water can drain, as wet roots in winter make the crown rot.

Diseases and pests

• Vine weevil: The grubs eat the roots, so the plant comes loose and wilts; the adults bite half-moon notches out of the leaf edges. Apply nematodes in spring or late summer.
• Crown rot: The plant collapses and the heart turns brown and soft, usually in wet soil. Replant in a better-drained spot.
• Leggy plant: After a few years the crown grows up out of the soil. Replant deeper in spring or divide it.
• Rust: Orange-brown pustules on the underside of the leaves. Cut off affected leaves and put them in the household waste.
• Leaf scorch: Brown, dry patches in strong sun or drought. Move it into more shade and water.

Through the year

• January: Evergreen leaves. Firm in frost-lifted plants later on.
• March: Remove old leaves. Replant leggy plants deeper.
• April: Plant or divide. Give compost. Nematodes against vine weevil.
• May: Plant. Water in dry spells.
• June: Flowering begins.
• July: Flowering. Water in dry spells, especially in pots.
• August: Cut off spent flower stems. Nematodes against vine weevil.
• September: Plant or divide.
• October: Plant. The leaves stay attractive into winter.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The genus is named after Johann Heinrich von Heucher, a German physician and botanist who lived around 1700.
• The variety ‘Palace Purple’ was selected at the Royal Botanic Gardens, Kew, near London, and is named after Kew Palace.
• Many modern heucheras in orange, lime or silver are hybrids with this species as one of their parents.