wetland shrub

Swamp Laurel

Kalmia polifolia

Native to the Northeast and the Midwest and Canada

Labrador to Alaska, south to Connecticut., northern prairie provinces, Washington and western U.S. mountains

In the garden

A wetland shrub for sun through shade and wet soil. At up to 3 ft, it suits rain gardens, pond edges, and damp low spots. Hardy in USDA zones 1–7.

Light

Full sun Partial shade Full shade

Moisture

Dry Moist Wet

Find your zone:

Bees Common Eastern Bumble Bee

also Western Honey Bee, Tricolored Bumble Bee, Perplexing Bumble Bee +7 more
Yellow-banded Bumble Bee, Neighborly Mining Bee, Sanderson's Bumble Bee, Bradley's Mining Bee, Toothed Miner Bee, Regular Mining Bee, Lasioglossum pilosum
Butterflies Northern Grizzled Skipper also Incisalia niphon
Flower flies Yellow-spotted Pond Fly

Documented host and nectar records. Each links to a planting guide for that butterfly.

Habitat: WetlandThe wild plant community it grows in.
Native range: The Northeast and the Midwest and CanadaUnited States (11): CT, MA, ME, MI, MN, MT, NH, NY, RI, VT, WI. Canada (10): AB, BC, MB, NB, NL, NS, ON, PE, QC, SK. Where it grows wild on its own, by state and province.
Native distribution: Labrador to Alaska, south to Connecticut., northern prairie provinces, Washington and western U.S. mountainsThe same native range, usually more exact than the state list, and often noting where it has spread beyond it.

Light: Full sun to shadeHow much sun it takes, from full sun to full shade.
Moisture: WetThe soil dampness it prefers, from dry to wet.
Hardiness zones: USDA 1–7 · Canadian 0–7The cold-to-heat climate range it survives.
Soil: Wet, organic soils & peatThe soils it grows in naturally.
Soil texture: Light to heavy (sandy to clay)The soil grade it prefers, from sand to clay.
Soil pH: 6.0–7.3The acidity to alkalinity it tolerates (7 is neutral).
Soil quality: LowHow rich a soil it needs. Many natives prefer lean soil and flop in rich beds.
Water use: MediumHow thirsty it is, a rough guide to how often to water.
Salinity tolerance: NoneHow well it copes with salty soil, near roads or the coast.
Lime (CaCO₃) tolerance: MediumHow well it copes with chalky, lime-rich soil.

Height: up to 3 ft (to 0.9 m)Typical mature height.
Spread: ~2 ft (0.5 m)How wide one plant gets, a guide to spacing.
Life cycle: PerennialWhether it lives a single season (annual), two (biennial), or returns for years (perennial).
Growth rate: SlowA relative ranking versus other plants of the same type (USDA), not an absolute rate.
Shape: DecumbentIts overall silhouette.
Root depth: 12+ in (30+ cm)How far the roots reach, a guide to drought resilience and transplanting.

Type: ShrubWhat kind of plant it is.
Bloom: May–JunWhen it flowers.
Flower color: White, PinkThe bloom color, or colors.
Toxicity: Poisonous if eatenWhether any part is poisonous to people or pets.

Cold stratification: Not requiredWhether seed needs a cold, moist spell before it will germinate.
Propagation: Bare root, container, cuttings, seedHow to start new plants.
Seed: ~25 million seeds per poundNotes on the seed and how to sow it.
Seed spread rate: SlowHow readily it self-sows. Slow or none means well-behaved, not a spreader.
Seedling vigor: LowHow strongly young seedlings establish.
Vegetative spread: SlowWhether it creeps outward or stays put in a clump.