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Kalmia latifolia

Phonetic Spelling
KAL-mee-ah lah-tih-FOH-lee-ah
This plant has high severity poison characteristics.
See below
Description

Kalmia latifolia, commonly called mountain laurel, is a dense, broadleaf evergreen shrub or small tree that is native to Eastern North America (New England south to the southern Indiana, Louisiana and the Florida panhandle) where it is found in a variety of habitats including open rocky or sandy woods, cool meadows, balds, mountain slopes, and woodland margins. It can grow to 6 to 10 feet.  It is noted for its excellent spring flowers and quality year round foliage.

It typically grows as a dense rounded shrub, opening up and developing gnarly branches with age. It blooms in late spring to early summer while buds, fruit, or inflorescence is visible year-round. Flowers have touch-sensitive anthers contained in pockets in the corolla, which triggers are release of pollen. Notwithstanding its usual shrub habit, mountain laurel will rarely grow as a small tree (particularly on slopes in the Appalachian Mountains) to as much as 32’ tall.

The Mountain laurel is best grown in cool, moist, rich, acidic, humusy, well-drained soils in part shade. Mulch to retain moisture and keep root zones cool. Plants tolerate a wide range of light conditions (full sun to full shade), but are best in part shade (morning sun with early to mid-afternoon shade). Raised plantings should be considered in order to promote better drainage. Plants do not grow well in heavy clay soils or wet soils. This plant has a slow growth rate and has known pest and disease problems. Remove spent flower clusters immediately after bloom. Prune lightly after bloom to promote bushy growth. 

Linnaeus named the genus herein after Swedish botanist Peter Kalm (1716-1779) who explored plant life in parts of eastern North America from 1747 to 1751. Kalmia latifolia is the state flower of Connecticut.

HIGHLY TOXIC, MAY BE FATAL IF EATEN!

Fire Risk: This plant has a high flammability rating and should not be planted within the defensible space of your home. Select plants with a low flammability rating for the sites nearest your home. 

Insects, Diseases, or Other Plant Problems:  Mountain laurel is susceptible to leaf spots and blights. Also susceptible to borers, scale, white fly and lace bugs.

Quick ID Hints:

  • Evergreen shrub with sympodial growth and elliptic leaves
  • Fruit, buds, or inflorescence is visible year-round
  • Terminal clusters of bell-shaped flowers are present in the late spring
  • Flowers have inner purple markings and 10 anther pockets
  • Old trunks and limbs are gnarly, cracked, and crooked
Cultivars / Varieties:
  • 'Bullseye'
  • 'Carol'
  • 'Carousel'
  • 'Elf'
    dwarf
  • 'Keepsake'
  • 'Minuet'
    dwarf, grows to 3'
  • 'Olympic Fire'
  • 'Pristine'
  • 'Richard Jaynes'
  • 'Sarah'
  • 'Snowdrift'
Tags:
#contorted trunk#hummingbirds#butterflies#evergreen#poisonous#interesting bark#wildlife plant#showy#native shrub#cover plant#dwarf#playground#cpp#fire#high flammability#NC native#children's garden#native garden#naturalizes#fantz#cover#hummingbird#butterfly
 
Cultivars / Varieties:
  • 'Bullseye'
  • 'Carol'
  • 'Carousel'
  • 'Elf'
    dwarf
  • 'Keepsake'
  • 'Minuet'
    dwarf, grows to 3'
  • 'Olympic Fire'
  • 'Pristine'
  • 'Richard Jaynes'
  • 'Sarah'
  • 'Snowdrift'
Tags:
#contorted trunk#hummingbirds#butterflies#evergreen#poisonous#interesting bark#wildlife plant#showy#native shrub#cover plant#dwarf#playground#cpp#fire#high flammability#NC native#children's garden#native garden#naturalizes#fantz#cover#hummingbird#butterfly
  • Attributes:
    Genus:
    Kalmia
    Species:
    latifolia
    Family:
    Ericaceae
    Life Cycle:
    Woody
    Country Or Region Of Origin:
    Eastern U.S.A
    Distribution:
    open rocky or sandy woods, cool meadows, balds, mountain slopes
    Fire Risk Rating:
    high flammability
    Wildlife Value:
    It provides winter cover. Hummingbirds and butterflies are attracted to the flowers. Although the foilage is toxic to domestic livestock, white-tailed deer browse the leaves and twigs during the winter and early spring.
    Play Value:
    Wildlife Food Source
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Highly resistant to damage from deer.
    Dimensions:
    Height: 6 ft. 0 in. - 10 ft. 0 in.
    Width: 5 ft. 0 in. - 15 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Poisonous
    Shrub
    Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Dense
    Multi-stemmed
    Open
    Rounded
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Dappled Sunlight (Shade through upper canopy all day)
    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:
    High Organic Matter
    Loam (Silt)
    Sand
    Shallow Rocky
    Soil pH:
    Acid (<6.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Available Space To Plant:
    6-feet-12 feet
    12-24 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    Usda Plant Hardiness Zone:
    4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    Plant produces 5-valved, dihiscent capsules (3/16") that are non-showy and brown in color that persist into winter.
  • Flowers:
    Flower Color:
    Pink
    Purple/Lavender
    White
    Flower Inflorescence:
    Corymb
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Shape:
    Saucer
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    Flowers appear on the Mountain laurel in terminal clusters (corymbs 4" to 6” in diameter), typically covering the shrub in late May-June for several weeks with an often exceptional bloom. Each flower (to 1” across) is cup-shaped with five sides and ranges in color from rose to white with purple markings inside of the corolla. There are 5 calyx lobes that are corolla campanulate. 5 lobes are pleated with 10 anthers that emerge at bloom (stamens included) but are at first tucked in small pockets.
  • Leaves:
    Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Green
    Leaf Feel:
    Glossy
    Leathery
    Leaf Value To Gardener:
    Long-lasting
    Showy
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Opposite
    Whorled
    Leaf Shape:
    Elliptical
    Lanceolate
    Oblanceolate
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    The Mountain laurel has elliptic to lanceolate or oblanceolate, simple, alternate, acute to short acuminate, cuneate, coriacious, entire, leathery, and congested glossy evergreen leaves (2" to 5” long) which are dark green above and yellow-green beneath and reminiscent to the leaves of rhododendrons. The leaves are occasionally opposite or whorled. New growth is yellow-green, yellows with age and falls off.
  • Bark:
    Bark Description:
    The bark is thin, smooth and dark red-brown in color in young trees. The barks shreds and splits as the tree ages. The trunk is contorted with cinnamon bark.
  • Stem:
    Stem Color:
    Brown/Copper
    Green
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Description:
    Stems are sympodial and initially bronze and sticky. As they mature, they turn turn red green or brown and become crooked and gnarly. Epidermis and gray-brown bark crack to reveal lighter colors in older stems. Pith is solid and light green.
  • Landscape:
    Landscape Location:
    Coastal
    Meadow
    Naturalized Area
    Recreational Play Area
    Woodland
    Landscape Theme:
    Butterfly Garden
    Children's Garden
    Native Garden
    Pollinator Garden
    Design Feature:
    Accent
    Flowering Tree
    Shade Tree
    Attracts:
    Butterflies
    Hummingbirds
    Resistance To Challenges:
    Deer
    Problems:
    Poisonous to Humans
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    Salivation, watering of eyes and nose, slow pulse, nausea, vomiting, sweating, abdominal pain, headache, tingling of skin, lack of coordination, convulsions, paralysis
    Poison Toxic Principle:
    Andromedotoxin, a resinoid; arbutin, a glycoside
    Causes Contact Dermatitis:
    No
    Poison Part:
    Bark
    Flowers
    Fruits
    Leaves
    Roots
    Seeds
    Stems