Mountain Laurel, Calico Bush, Spoonwood, Ivy Bush, American Laurel, Laurel, Mountain Ivy, Sheepkill
Kalmia latifolia (Mountain Laurel), the state flower of Connecticut and Pennsylvania, is a striking broadleaf evergreen shrub or small tree native to eastern North America. In late spring to early summer, it dazzles with clusters of bell-shaped flowers, opening from deep pink buds to reveal pale pink or white petals adorned with rose markings. Its glossy, leathery leaves transition from light green to deep green to purplish hues throughout the year. A standout ornamental plant, Mountain Laurel thrives in woodlands and gardens alike, offering year-round beauty and exceptional seasonal interest.
A close relative of rhododendrons and azaleas, blueberries and cranberries, pieris, and heath and heather, Mountain Laurel belongs to the heath family (Ericaceae). The Kalmia genus consists of 10 species of evergreen shrubs, including the renowned Mountain Laurel (Kalmia latifolia). Other notable species include Sheep Laurel (Kalmia angustifolia), Sand Myrtle (Kalmia buxifolia), and Alpine Laurel (Kalmia microphylla), all admired for their striking flowers and adaptability to acidic soils.
Mountain Laurel is native to the eastern United States. Its range extends from southern Maine south to northern Florida and west to Indiana and Louisiana. It thrives in rocky or sandy acidic soils on mountain slopes, stream bluffs, and in dense thickets. Mountain Laurel is also found in Canada, specifically in southern Ontario.
Mountain Laurel is a broadleaf evergreen shrub or small tree with a dense, rounded, and multi-stemmed growth habit. Over time, it can develop gnarly, picturesque branches, giving it a unique, sculptural appearance.
Mountain Laurel typically grows between 5 to 15 feet (1.5 to 4.5 meters) in height and spread, depending on growing conditions. In ideal settings, particularly on slopes in the Appalachian Mountains, it can occasionally reach up to 30 feet (9 meters) tall. The plant has a slow growth rate, typically adding 6 to 12 inches (15 to 30 cm) per year. While it takes several years to establish, once mature, it becomes a long-lasting and resilient landscape plant.
Mountain Laurel is a long-lived shrub, with individual plants surviving for 50 to 100 years under favorable conditions. In natural woodland settings, it can persist for generations, forming dense thickets that provide habitat for wildlife.
The flowers of Mountain Laurel are its most captivating feature. Blooming for several weeks in late spring to early summer, they appear in large, dense clusters (corymbs) and range from pale pink to deep rose, often with deep rose markings inside. Each cup-shaped flower has unique anther pockets that catapult pollen onto visiting pollinators.
Following flowering, Mountain Laurel produces small, brown, five-valved seed capsules that persist through the winter.
Mountain Laurel boasts evergreen, leathery leaves that provide year-round interest. The foliage is dark green and glossy on the upper surface, while the undersides are a lighter shade of green. Leaves are simple, alternate, and elliptical, measuring 2 to 5 inches (5-13 cm) long and resembling those of rhododendrons.
New growth emerges as light green in spring before maturing into a rich, deep green. In colder months, leaves may take on a purplish-bronze tint, adding seasonal interest. The dense, evergreen foliage creates an excellent natural screen, making it a popular choice for hedges, woodland plantings, and foundation gardens.
Young bark is smooth and reddish-brown, becoming rough and gnarled with age. Older plants develop twisted, picturesque trunks with cracked, cinnamon-colored bark.
Mountain Laurel is hardy in USDA zones 4-9, tolerating cold winters and thriving in partial shade.
Winner of the Cary Award, which recognizes plants that are particularly adequate for New England, offer superior landscape appeal, are winter hardy, and are pest resistant.
Mountain Laurel, is generally considered drought-tolerant once established. However, it performs best in moist, well-draining soils and benefits from occasional watering, especially during prolonged dry spells.
Mountain Laurel is deer-resistant due to its toxic foliage, which deters browsing.
Mountain Laurel is a highly toxic plant dangerous to humans, pets, and livestock. All parts of the plant, including bark, leaves, flowers, and seeds, contain grayanotoxins and arbutin, which can disrupt muscle, nerve, and heart function. Symptoms include nausea, vomiting, drooling, abdominal pain, weakness, leg paralysis, and cardiac failure. While not typically palatable to horses, sheep and goats may graze on it readily. In severe cases, ingestion can lead to coma and death within days. Poisonous flowers and plants: Identifying toxic risks around you
Mountain Laurel is not considered invasive but can form dense thickets in undisturbed areas.
Mountain Laurel can be propagated through several methods, including seeds, cuttings, and layering. While seed propagation is slow and less reliable, stem cuttings and layering offer faster results with higher success rates.
Although Mountain Laurel is relatively low-maintenance and pest-resistant, it can still be affected by several pests and diseases. Proper care, including well-draining soil and good air circulation, can help prevent many issues.
No, Mountain Laurel (Kalmia latifolia) and Bay Laurel (Laurus nobilis) are unrelated. Bay Laurel is a Mediterranean herb used for cooking, while Mountain Laurel is a North American ornamental shrub.
Mountain Laurel thrives in well-draining, acidic soils with a pH between 5.0 and 6.5. It prefers partial shade to dappled sunlight, though it can tolerate full sun in cooler climates. Deep shade may reduce flowering. It grows best in consistently moist soil but dislikes overly wet or compacted conditions. Mulching helps retain moisture and regulate soil temperature.
Water regularly, especially during the first year, to establish a strong root system. Keep the soil consistently moist but not soggy. Once established, Mountain Laurel is somewhat drought-tolerant but benefits from occasional deep watering during dry periods. Avoid standing water or excessive moisture, as this can lead to root rot and other fungal issues.
Mountain Laurel is a slow-growing shrub, typically adding about 6 to 12 inches (15 to 30 cm) per year. Under optimal conditions, it can reach a height of 5-10 feet (1.5 to 3 meters) over several years. In some cases, particularly in shaded or less favorable locations, growth may be even slower. Mature plants develop a dense, bushy habit.
Prune lightly after flowering to maintain shape and encourage bushier growth. Remove dead or damaged branches and spent flower clusters. If needed, Mountain Laurel can tolerate more aggressive pruning for rejuvenation, but it may take several years to fully recover. Regular trimming enhances air circulation and reduces the risk of fungal diseases.
Yes, Mountain Laurel is highly toxic to humans and animals due to its grayanotoxin content. Ingesting any part of the plant can cause severe digestive distress, weakness, and even cardiac issues. It is especially dangerous for livestock, pets, and wildlife. Avoid handling the plant if you have sensitive skin, as mild irritation may occur.
Mountain Laurel can be affected by pests such as lace bugs, weevils, whiteflies, and scale insects. Common diseases include root rot, powdery mildew, leaf spot, and sooty mold. Proper care, including good air circulation, well-draining soil, and avoiding overwatering, helps prevent most issues. Applying neem oil or insecticidal soap can manage minor infestations.
Yes, Mountain Laurel can be successfully grown in containers if provided with an acidic, well-draining potting mix. Choose a large, deep container to accommodate its slow but steady growth. Regular watering is necessary to prevent the soil from drying out too quickly. Container-grown plants may require occasional fertilization and winter protection in colder climates.
Hardiness |
4 - 9 |
---|---|
Heat Zones |
5 - 9 |
Climate Zones | 2, 3, 4, 5, 6, 7, 16, 17 |
Plant Type | Shrubs, Trees |
Plant Family | Ericaceae |
Common names | Mountain Laurel |
Exposure | Partial Sun |
Season of Interest | Spring (Late), Summer (Early) |
Height | 5' - 15' (150cm - 4.6m) |
Spread | 5' - 15' (150cm - 4.6m) |
Spacing | 96" - 120" (240cm - 3m) |
Maintenance | Low |
Water Needs | Low, Average |
Soil Type | Clay, Loam, Sand |
Soil pH | Acid, Neutral |
Soil Drainage | Moist but Well-Drained, Well-Drained |
Characteristics | Plant of Merit, Showy, Evergreen |
Native Plants | United States, Northeast, Pennsylvania, Rhode Island, Vermont, Connecticut, Delaware, Maine, Massachusetts, Maryland, New Hampshire, New Jersey, New York, Ohio, Indiana, Midwest, Southeast, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, West Virginia, Alabama, Florida, Georgia, Kentucky |
Tolerance | Deer, Rabbit, Dry Soil, Rocky Soil |
Attracts | Butterflies, Hummingbirds |
Garden Uses | Beds And Borders, Hedges And Screens |
Garden Styles | Prairie and Meadow, Informal and Cottage, Coastal Garden |
Hardiness |
4 - 9 |
---|---|
Heat Zones |
5 - 9 |
Climate Zones | 2, 3, 4, 5, 6, 7, 16, 17 |
Plant Type | Shrubs, Trees |
Plant Family | Ericaceae |
Common names | Mountain Laurel |
Exposure | Partial Sun |
Season of Interest | Spring (Late), Summer (Early) |
Height | 5' - 15' (150cm - 4.6m) |
Spread | 5' - 15' (150cm - 4.6m) |
Spacing | 96" - 120" (240cm - 3m) |
Maintenance | Low |
Water Needs | Low, Average |
Soil Type | Clay, Loam, Sand |
Soil pH | Acid, Neutral |
Soil Drainage | Moist but Well-Drained, Well-Drained |
Characteristics | Plant of Merit, Showy, Evergreen |
Native Plants | United States, Northeast, Pennsylvania, Rhode Island, Vermont, Connecticut, Delaware, Maine, Massachusetts, Maryland, New Hampshire, New Jersey, New York, Ohio, Indiana, Midwest, Southeast, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, West Virginia, Alabama, Florida, Georgia, Kentucky |
Tolerance | Deer, Rabbit, Dry Soil, Rocky Soil |
Attracts | Butterflies, Hummingbirds |
Garden Uses | Beds And Borders, Hedges And Screens |
Garden Styles | Prairie and Meadow, Informal and Cottage, Coastal Garden |
How many Kalmia latifolia (Mountain Laurel) do I need for my garden?
Plant | Quantity | |
---|---|---|
Kalmia latifolia (Mountain Laurel) | N/A | Buy Plants |
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Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.
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