Mountain laurel

About Mountain laurel

Mountain laurel is a native broadleaf evergreen of the eastern US with clusters of cup-shaped pink, white or red-marked flowers in late spring. Each flower has spring-loaded stamens that dust visiting bees with pollen. It grows slowly into a dense shrub 6-10 ft tall, likes cool, moist, acid soil and part shade, and every part of the plant is highly poisonous (NC State).

Native from New England to the Florida panhandle and Louisiana; hardy in zones 4-9 (NC State).

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Plant container shrubs in spring or fall and water deeply until established (UMN). Morning sun with shade from early afternoon on suits it best (NC State).

Soil

Cool, moist, acid, well-drained soil high in organic matter; it fails in heavy clay or wet soil, so use raised beds there, and mulch to keep the roots cool (NC State).

Mountain laurel needs cool, moist, acid, well-drained soil high in organic matter; use raised beds in heavy clay (NC State). Test the soil first.

Feeding

• Spring to early summer after new growth starts, only if a soil test shows a need: slow-release complete fertilizer in a 3:1:2 ratio, or what the soil test calls for. Spread evenly from the trunk out to the drip line and water it in; a typical soil-test rate for shrubs is about 2 lb of 12-6-6 per 100 sq ft (Clemson). Follow a soil test.

Water is what new shrubs need most: daily for the first 2 weeks, every 2-3 days through week 12, then weekly until the roots spread (at least two growing seasons), using about a quarter to a third of the nursery pot's volume each time (UMN). Mulch to keep roots cool and moist (NC State).

Harvest

Blooms late April to July for several weeks. Snap off spent flower clusters after bloom and prune lightly then; next year's buds form on old growth (NC State).

Varieties (12)

NC State documents these.

Pests to watch for

Lace bugs (azalea and chrysanthemum lace bugs), Scale insects, Whiteflies, Deer

Diseases and problems

Leaf spots, Blight, Leaf scorch

In the kitchen

Safety: NC State rates poisoning as high severity: grayanotoxins in all parts can cause drooling, vomiting, weakness, a weak heartbeat and, in severe cases, death. Honey made mostly from its nectar can be toxic to people.

Pets: Toxic to dogs, cats and horses (ASPCA): grayanotoxins cause vomiting (not in horses), diarrhea, weakness and heart failure.