alpine laurel
Kalmia microphylla · Ericaceae
alpine laurel (Kalmia microphylla) is a perennial shrub in the Ericaceae family. It is native to North America. USDA records it as hardy in zone 4 and warmer, down to about -28°F.
At a glance
| Type | shrub USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 1 ft USDA |
| Light | shade USDA |
| Water need | medium USDA |
| Growth rate | slow USDA |
| Soil pH | 6–7.3 USDA |
| Bloom | May–June USDA |
| Flower color | Purple USDA |
| Hardiness zones | 4 and warmer USDA |
| Guild layer | shrub Derived |
| Nursery availability | Contracting Only USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It tolerates full shade. USDA rates it as having moderate water needs. Its drought tolerance is rated low. It handles periodically wet ground (USDA rates its anaerobic tolerance medium). It is recorded on soils from pH 6 to 7.3 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 4.
Size and growth
At maturity it reaches about 1 ft, making it a low, mat-forming plant. It grows slowly.
Bloom period
USDA records a bloom period of May through June. Flowers are purple.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is dark green, coarse in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as long.
What the site needs to provide
USDA records it across sites receiving 12 to 20 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 85 frost-free days to finish its season. It roots to at least 12 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
Propagating it
It takes readily from seed, cuttings, bare root and container stock. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It spreads vegetatively at a slow rate.
Resilience and wildlife
Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated medium, and it can resprout after damage. Its growth form is recorded as multiple stem.
Role in a guild
Shrub layer. In a layered planting this is woody mid-level structure between the understory and the ground. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Kalmia
- mountain laurel Kalmia latifolia
- bog laurel Kalmia polifolia
Similar role and hardiness
- Utah serviceberry Amelanchier utahensis
- greenleaf manzanita Arctostaphylos patula
- forage kochia Bassia prostrata
- Japanese barberry Berberis thunbergii
- New Jersey tea Ceanothus americanus
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol KAMI, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, lifespan, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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