Sheep laurel

Sheep laurel: how do you recognise it?

Habit

Compact, dense shrub about 0.8 m high and 1 m wide; forms underground suckers.

Leaves

Evergreen; narrow, lance-shaped, 2–5 cm long, dark green, often in whorls of three. Turn slightly reddish brown in winter.

Flowers

Small, cup-shaped flowers in clusters around the stems, pink to crimson, in June and July.

Fruit

Small, round capsules that stay on the plant for a long time.

Roots

Fine and fibrous, just under the surface; it likes cool, moist soil.

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

Why grow it?

• Green all year and low-growing, so also suitable for small gardens and containers.
• Pink to crimson flower clusters in June–July, when many other shrubs are resting.
• Does well on moist, acid soil, where other plants struggle.
• Bees visit the flowers.
• Combines well with rhododendron, heather and other lime-hating plants.

Sheep laurel: where does it grow best?

• Sun to partial shade; in sun it flowers more freely, as long as the soil stays moist.
• Acid, humus-rich, moist soil: sandy or peaty, pH below 6. No lime.
• Likes cool, moist soil, but not standing water.
• Sheltered from dry wind; allow about 1 m of space per plant.

Light

Sun and partial shade

Soil type

Sand or peat

Acidity

Acid

Moisture

Normal or wet

Size

0.8 m tall, 1 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Rhododendron: Likes the same acid, moist soil.
• Heather: A low, flowering patch of colour in the same heather garden.
• Blueberry: Lime-hating, with fine autumn colour and edible fruit.
• Ferns: Fresh, green underplanting in partial shade.
• Pieris: Also evergreen and lime-hating, with spring flowers.

Sheep laurel: 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 waterlogged.
2. Dig a generous hole and mix the soil with acidic leaf mould or ericaceous compost (no lime), especially on sandy soil.
3. Set the plant at the same depth as in its pot; plant shallowly, as the roots lie close to the surface.
4. Water thoroughly straight away, preferably with rainwater, and keep the soil moist in the first year.
5. Cover the soil with pine bark, pine needles or leaf mould, keeping it clear of the stem.

Care

Water

Keep the soil moist, especially in the first year and in dry summers. Use rainwater if you can: hard tap water raises the pH.

Feeding

In spring, a fertiliser for rhododendrons and other lime-hating plants, or acidic compost.

Mulching

A layer of pine bark or leaf mould keeps the roots cool and the soil acid.

Deadheading

Cut off the faded clusters after flowering: the plant then sets no seed and flowers more freely the next year.

In a container

Use a wide pot with ericaceous compost; keep the soil lightly moist at all times.

Tip: Plant it in acid, moist soil and water with rainwater if you can. Cut off faded clusters, but keep the poisonous clippings out of reach of animals.

Sheep laurel: when to prune it?

Pruning months: April and July.

When: It hardly needs pruning. Cut off faded clusters in July and, if necessary, dead or damaged branches in April.

How:

• Cut off faded clusters just below the flower, to prevent seed forming.
• Remove dead, weak or damaged branches in spring.
• Keep the shape by occasionally cutting an overly long branch back to just above a side shoot.
• Wear gloves and dispose of the clippings, as all parts are very poisonous.

Caution: Do not prune too hard into old wood: the shrub recovers slowly. The clippings are poisonous to people and animals, especially grazers.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

In February–March: the seed is very fine and germinates in the light. Sprinkle it on moist ericaceous compost and do not cover it. The seedlings grow slowly.

Suckers

In spring, dig up a sucker with roots and plant it in a moist spot with acid soil.

Sheep laurel: how does it get through the winter?

Hardy to −35 °C.

• Very hardy, to about −35 °C: no protection is needed in Belgian winters.
• The leaves may turn reddish brown in winter; this is normal and says nothing about the plant’s health.
• In a pot: place it in a sheltered spot and wrap the pot in hessian or bubble wrap so the roots do not freeze.

Diseases and pests

• Yellow leaves (chlorosis): Yellow leaves with green veins on soil that is too chalky or from tap water. Use rainwater and mix acidic leaf mould into the soil.
• Leaf spots: Brown or grey spots on the leaves caused by a fungus. Remove affected leaves and avoid wetting the foliage when watering.
• Drought: Brown leaf edges and few flowers when the soil dries out. Mulch the soil and water generously in dry summers.
• Winter scorch: Brown foliage after dry wind and sun in winter. Choose a sheltered spot and keep the soil moist in autumn.

Through the year

• March: Plant. Give acidic compost or fertiliser.
• April: Plant. Remove dead branches. Apply mulch.
• May: Water in dry weather. Buds form.
• June: Flowering begins.
• July: Flowering. After flowering, cut off faded clusters.
• August: Water in dry weather.
• September: Plant. Collect seed if wanted.
• October: Plant. Top up the mulch.
• November: Keep the soil moist; water in a dry autumn.

Edible and useful

Not edible. All parts of kalmia are highly poisonous, especially the leaves, flowers and nectar: like rhododendron it contains grayanotoxins, which cause drooling, vomiting, weakness and a slow heartbeat. Sheep, goats and alpacas above all, but also horses, cattle, rabbits and guinea pigs are at risk; the narrow-leaved species is not called lambkill for nothing. Do not plant it next to a field, never throw clippings over the fence or into a pen or hutch and do not give them to animals; if an animal has eaten some, call your vet at once. Keep small children, dogs and cats away from the leaves and flowers too, and wear gloves when pruning. 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 English name ‘lambkill’ refers to the poisoning of lambs and other livestock that browse on the plant.
• The genus Kalmia is named after Pehr Kalm, a Swedish-Finnish botanist and student of Linnaeus who travelled in North America.
• The stamens of the flower are held in small pockets in the corolla and spring free when an insect touches them, flinging out the pollen.