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Kalmia polifolia

Bog Laurel · Pale Laurel · Swamp Laurel

Family EricaceaeGenus Kalmia

Pink flowers at the tip of a wiry stem with narrow dark leaves
Flowerphoto by user MeggarCC BY-SA 3.0

About the plant

What it is and where it grows — not part of any germination protocol.

Safety

Toxicity
High severity. All parts. Andromedotoxin, arbutin, Grayanotoxin.Extension Gardener Plant Toolbox

The plant

Habit
Ground Cover, Perennial, Shrub, Water PlantExtension Gardener Plant Toolbox
Habit
subshrub or shrubPlants of the World Online
Height
1-3 ft30-90 cmExtension Gardener Plant Toolbox
Spread
1-3 ft30-90 cmExtension Gardener Plant Toolbox
Flower
Pink, Purple/Lavender, WhiteExtension Gardener Plant Toolbox
Blooms
SpringExtension Gardener Plant Toolbox
Native range
Canada, lower 48 states, St. Pierre and MiquelonPLANTS Database
Hardiness zones
1-5Extension Gardener Plant Toolbox

Growing conditions

Sun
Dappled Sunlight; Deep shade; Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, High Organic Matter, Loam (Silt), SandExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasional Flooding, Occasionally WetExtension Gardener Plant Toolbox
Watering
Drought tolerance: LowPLANTS Database

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS.

Worth knowing

  • Every part is highly toxic, though less so than its relative lambkill. It contains a grayanotoxin, which lowers blood pressure when eaten. Wikipedia: Kalmia polifolia

Protocol

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

  1. Separate the seed from its case

    Crush the hard capsule so light can reach the seed.

  2. Sow on the surface — do not cover

    Temperature: 70°F 21°C Light: light

No stated waiting before sowing.

Jaynes found it needs light. That is all this passage says about this species.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, KalmiaPublic domain
Show the original text
Kalmia (Ericaceae). Kalmia requires light as found by R. Jaynes for K. angustifolia, K. cuneata, K. hirsuta, K. latifolia, K. microphylla, and K. polifolia (ref. 41) and confirmed by myself for K. angustifolia and K. latifolia. The seed is contained in hard spherical capsules. These must be crushed to allow light to reach the seed. The seed is small and hard to separate from the hard capsules so that seed counts and percent germination are inaccurate.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Kalmia. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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