Mountain laurel
Kalmia latifolia
also called calico bush, spoonwood
The native evergreen of Appalachian understories: clusters of crimped, origami-perfect cups in pink and white through June, on a broadleaf evergreen that keeps the shade garden furnished all winter.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Pink
- Sunlight
- Dappled or half shade; deep shade costs the bloom
- Watering
- Moderate; mulch the shallow roots and never cultivate over them
- Soil
- Acid, cool, moist, sharply drained; an azalea root run
- Feeding
- Gentle all-organic
- USDA zones
- 4b–9a
- Frost tolerant
- Yes
- Plant out
- at the last spring frost
- Plant spacing
- 8 ft 2 in
- In-row spacing
- 6 ft 7 in
- Between rows
- 9 ft 10 in
- Square-foot density
- Not suited to SFG
- Root system
- A fine surface mat, and nothing below it
- Working depth
- 4–12 in
- Can reach
- 18 in down where the soil allows
- Spread
- 10–15 ft across, about 1–1.5× the width of the plant
- Shallowest pot
- 16 in of soil
Hair-fine roots in a shallow felt, with no deep anchor to fall back on. It cannot chase water, so it is the first casualty of a drought and the first thing killed by a hoe. Mulch it, never cultivate around it, and never let it go dry in its first two summers.
The habit is Mountain laurel’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Cats and dogs
- Recorded toxic
Recorded as toxic to cats and dogs by ASPCA.
Exact species match. The ASPCA also carries Bog Laurel and Lambkill as separate Kalmia rows.
- When
- Not harvested, and not for the vase in a house with browsing pets: all parts are toxic. Deadhead after the June bloom.
- What to look for
- Flower clusters browning and setting seed; seedpods cost next year some bloom energy.
- How to harvest
- Snap the spent clusters off with fingers, carefully; next year's buds form just below them. No other pruning beyond deadwood, and no cultivating over the shallow roots, ever.
- How often
- One deadheading in late June where you can reach; the shrub forgives what you skip.
- Storing the crop
- Nothing to store. Renew the acid mulch each fall and it asks for nothing else for decades.
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Assassin bug ReduviidaeHunts Lace bugs
A patient ambusher with a curved beak it drives into whatever it catches — caterpillars, beetles, bugs, and the occasional bee, so count it a generalist rather than a specialist. It will jab a careless finger too, so admire it and leave it be.
- Green lacewing Chrysoperla carneaHunts Lace bugs
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Minute pirate bug Orius spp.Hunts Lace bugs
A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.
State flower of Connecticut and Pennsylvania. Each flower holds its ten stamens bent back like set springs and flings pollen onto the bee that trips them. Every part is toxic, and even honey made largely from it is suspect: plant it for the eyes, not the table.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com