Bog Laurel Kalmia polifolia
Other Common Name(s):
Previously known as:
- Kalmia glauca
- Phonetic Spelling
- KAL-mee-ah poh-lih-FOH-lee-ah
- This plant has high severity poison characteristics.
- See below
- Description
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Bog Laurel is a low growing, mat-forming, perennial evergreen shrub or sub-shrub in the heath family and a native of an extensive range from subarctic America to North Central and North Eastern United States. In the wild, it is often found in cold peat bogs. Bog Laurel can reach a mature height of 2 to 3 feet with an equal width. It is in leaf all year, produces showy pink or purple, bell-shaped flowers in spring, and the seeds ripen in September. The genus name honors Pehr Kalm, a Swedish botanist and student of Linnaeus. The species name is Latin for pole -leaves.
Bog Laurel does well in sandy or loamy, mildly acidic soil, but also tolerates clay soil. It is shade and flood tolerant and prefers a site with good drainage. Propagate by seeds or stem cuttings in the summer. It is a slow growing plant with a long lifespan and can take up to 20 years to reach full height. The plant can be pruned, but keep in mind that next year's blossoms will appear on old growth.
Bog Laurel is highly toxic and the foliage, in particular, is poisonous to animals. The plant is polinated by bees and, it is said, that the resulting honey is also poisonous.
Diseases, Insect Pests, and Other Plant Problems:
Chlorosis, or yellowing of the leaves, is usually caused by an iron deficiency in limy soils.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Kalmia
- Species:
- polifolia
- Family:
- Ericaceae
- Life Cycle:
- Perennial
- Woody
- Recommended Propagation Strategy:
- Seed
- Stem Cutting
- Country Or Region Of Origin:
- Subarctic North America, eastern Canada, south to Pennsylvania.
- Distribution:
- Introduced to Great Britain
- Wildlife Value:
- Composes 11% of Canadian Caribou diet.
- Edibility:
- very poisonous narcotic plant
- Dimensions:
- Height: 1 ft. 0 in. - 3 ft. 0 in.
- Width: 1 ft. 0 in. - 3 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Ground Cover
- Perennial
- Poisonous
- Shrub
- Water Plant
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Habit/Form:
- Dense
- Multi-stemmed
- Prostrate
- Growth Rate:
- Slow
- Maintenance:
- Low
- Texture:
- Coarse
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Cultural Conditions:
- Light:
- Dappled Sunlight (Shade through upper canopy all day)
- Deep shade (Less than 2 hours to no direct sunlight)
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- High Organic Matter
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasional Flooding
- Occasionally Wet
- Available Space To Plant:
- 12 inches-3 feet
- USDA Plant Hardiness Zone:
- 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b
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Fruit:
- Fruit Color:
- Brown/Copper
- Display/Harvest Time:
- Fall
- Fruit Type:
- Capsule
- Fruit Description:
- Woody capsule, winged seeds are five-parted, round.
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Flowers:
- Flower Color:
- Pink
- Purple/Lavender
- White
- Flower Inflorescence:
- Raceme
- Solitary
- Flower Value To Gardener:
- Showy
- Flower Bloom Time:
- Spring
- Flower Shape:
- Bell
- Flower Size:
- < 1 inch
- Flower Description:
- Showy, pink, 3/8 of an inch bell-shaped flowers appear in clusters of 2 to 5 blooms in May and June.
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Leaves:
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Leaf Color:
- Blue
- Green
- Leaf Feel:
- Leathery
- Leaf Value To Gardener:
- Long-lasting
- Leaf Type:
- Simple
- Leaf Arrangement:
- Opposite
- Leaf Shape:
- Linear
- Oblong
- Leaf Margin:
- Entire
- Hairs Present:
- Yes
- Leaf Length:
- 1-3 inches
- Leaf Width:
- 1-3 inches
- Leaf Description:
- Glossy, leathery, dark blue-green foliage, waxy with an entire and revolute margin. Below each leaf base there are ridges and it appears as though the leaf curls around the stem. This is especially noticeable lower on the plant.
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Stem:
- Stem Is Aromatic:
- No
- Stem Cross Section:
- Angular
- Stem Surface:
- Smooth (glabrous)
- Stem Description:
- Slightly flattened, 2-angled, sticky, glabrous or puberulent in downward lines from petiole base.
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Landscape:
- Landscape Location:
- Meadow
- Woodland
- Landscape Theme:
- Rain Garden
- Shade Garden
- Design Feature:
- Border
- Attracts:
- Bees
- Resistance To Challenges:
- Wet Soil
- Problems:
- Poisonous to Humans
- Problem for Cats
- Problem for Dogs
- Problem for Horses
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Poisonous to Humans:
- Poison Severity:
- High
- Poison Symptoms:
- Typically not very palatable to horses unless it is the only forage available, but sheep and goats may graze readily on the plant. The toxic principle interferes with normal skeletal muscle, cardiac muscle and nerve function. Clinical effects typically occur within a few hours after ingestion, and can include acute digestive upset, excessive drooling, loss of appetite, frequent bowel movements/diarrhea, colic, depression, weakness, loss of coordination, stupor, leg paralysis, weak heart rate and recumbency for 2 or more days; at this point, improvement may be seen or the animal may become comatose and die. Watering of eyes and nose, nausea, vomiting, sweating, abdominal pain, headache, tingling of the skin, convulsions, cardiac failure
- Poison Toxic Principle:
- Andromedotoxin, arbutin, Grayanotoxin
- Causes Contact Dermatitis:
- No
- Poison Part:
- Flowers
- Fruits
- Leaves
- Roots
- Sap/Juice
- Seeds
- Stems
