Cornish heath

Cornish heath: how do you recognise it?

Habit

Low, dense, cushion-forming dwarf shrub, 30–40 cm tall and 50–60 cm wide.

Leaves

Fine, needle-like leaves of about 1 cm, in whorls of four or five; fresh to dark green all year.

Flowers

Tiny bells in dense, upright spikes up to 15 cm long, from August to October. The brown anthers stick out of the flower.

Colour

Pink, lilac, purple-red or white depending on the cultivar. There are also cultivars with yellow-green foliage.

Roots

Fine and shallow, as in all heathers: they like light, humus-rich soil and dry out quickly.

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

Why grow it?

• Flowers from August into October, long after most shrubs have finished.
• An important source of nectar for bees, bumblebees and hoverflies in late summer.
• Evergreen: a fresh green, dense mound all year round, also lovely on a bank or along a path.
• Tolerates neutral soil better than ling heather, so it is easier in an ordinary garden.
• The faded spikes turn russet brown and stay attractive all winter.
• Little work: one trim a year in spring keeps it compact.

Cornish heath: where does it grow best?

• Sun or light partial shade; in full sun it flowers most freely and stays most compact.
• Light, humus-rich soil: sand, loam or peat, acid to neutral. Chalky soil is best avoided.
• Normally moist soil that drains well: no wet feet in winter, but no drying out in summer either.
• An open spot with plenty of light and air; under trees it becomes sparse and flowers poorly.
• Plant 40–50 cm apart, in groups of three to five, for a closed carpet.

Light

Sun and partial shade

Soil type

Sand, loam or peat

Acidity

Acid or neutral

Moisture

Normal

Size

0.4 m tall, 0.6 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Ling heather: Flowers at the same time in other shades and needs the same light, acid soil.
• Winter heath: Takes over flowering from December to April, so there is heather in bloom almost all year.
• Dwarf conifers: Add height and shape among the low heather cushions.
• Purple moor grass: A native heathland grass that adds movement and autumn colour.
• Dwarf rhododendron: Low evergreen shrub with spring flowers for the same acid soil.

Cornish heath: 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 not frozen or waterlogged.
2. Dig a hole twice as wide as the root ball and mix in leaf mould or ericaceous compost.
3. Set the plant at the same depth as in the pot, or slightly deeper so the lowest shoots rest on the soil, and firm well.
4. Leave 40–50 cm between plants.
5. Water in thoroughly straight away, preferably with rainwater.
6. Mulch with pine needles, fine bark or leaf mould to keep the soil cool, moist and slightly acidic.

Care

Watering

In the first year, water regularly in dry spells, preferably with rainwater. After that only in long droughts: the fine roots dry out quickly.

Feeding

Hardly needed. At most, a thin layer of leaf mould or a little organic ericaceous fertiliser in April.

Mulching

A thin layer of pine needles or fine bark between the plants every spring suppresses weeds and keeps the soil moist.

Weeding

Weed by hand between young plants; hoeing damages the shallow roots.

Spent flowers

Leave the russet spikes over winter: they look good and protect the plant. Only cut them off in spring.

Tip: Want heather on less acidic soil? Choose this species: it tolerates neutral soil far better than ling. In spring, clip off the old spikes, but always stay in the green.

Cornish heath: when to prune it?

Pruning months: March–April.

When: In March–April, just before new growth starts and once the hardest frosts are over.

How:

• Clip or shear off the old flower spikes just below the faded flowers.
• Stay in the green: never cut into bare, old wood, as heathers rarely reshoot from it.
• A large group is quickly trimmed with hedge shears.
• Trimming every year keeps the plant dense and prevents a bare, sprawling mound with an open centre.

Caution: A neglected, leggy heather rarely recovers from hard pruning into old wood; replace it with a young plant instead.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In August–September, take tip cuttings of 3–5 cm from non-flowering shoots, strip the lower leaves and insert in a mix of ericaceous cutting compost and sand under plastic. Plant out in spring.

Layering

In spring, press a low shoot onto the soil, cover with a little sand and compost and peg it down; sever and replant after a year.

Cornish heath: how does it get through the winter?

Hardy to −20 °C.

• Fully hardy, to about −20 °C: no protection is needed in Belgian gardens.
• The brown, faded spikes stay in place and give structure to the winter garden.
• Cold, drying east winds can brown the foliage; the plant usually reshoots normally in spring.
• In a pot or container: place it in a sheltered spot, wrap the pot in hessian and give a little water on dry, frost-free days.

Diseases and pests

• Root rot: Shoots suddenly wither and turn brown on wet, heavy soil. Choose a well-drained spot and remove affected plants.
• Leggy plant: The centre opens up and the plant turns woody. Caused by years without trimming; replace an old plant with a young one.
• Yellow leaves: Yellowing foliage on chalky soil or from hard tap water. Work in acidic leaf mould and water with rainwater.
• Vine weevil: Mainly in pots and containers: the grubs eat the roots and the plant wilts. Apply nematodes in late summer.

Through the year

• March: Cut off old flower spikes. Plant.
• April: Last trim. Plant. Apply a thin mulch.
• May: New shoots. Weed by hand.
• June: Water in dry spells, preferably with rainwater.
• July: Water in dry spells. Flower spikes are forming.
• August: Flowering begins. Take cuttings.
• September: Full bloom, busy with bees. Plant.
• October: Last flowers. Plant.
• November: Leave the faded spikes in place.
• December: Rest. The russet spikes decorate the winter garden.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• In 2002, Erica vagans was chosen by public vote as the county flower of Cornwall.
• In the wild in Cornwall it grows mainly on the Lizard peninsula, on serpentine soils that are less acidic than ordinary heathland soil.
• The species name vagans means ‘wandering’.