New This Week
March 11, 2024
Plant of the Week: Mountain Laurel
Kalmia latifolia
BASIC FEATURES:
Broadleaf, evergreen shrub with clusters of spring blooms May/June. Tight, compact habit while young and growing into an open form with gnarly trunks as it ages.
WHAT’S IN A NAME?
Kalmia latifolia. Kalmia named after Swedish-Finnish botanist Pehr Kalm. Kalm was a disciple of Carl Linnaeus and explored eastern N. America extensively during the mid-1700s. We can thank Carl Linnaeus for the binomial system of naming plants (genus and species latin names). Latifolia translates to “with broad leaves.”
FAMILY:
Ericaceae (Heath) – family members include rhododendron, blueberries, azaleas, bearberries, andromeda, etc.
NATIVE RANGE:
Native to eastern North America from New Brunswick south to Florida and west to Tennessee.
FUN FACT:
Pollen catapults! Mountain laurel flowers evolved to have the pollen producing flower parts (stamens) tucked into the walls of the petals. When a bumblebee visits, the movement and vibrations inside the flower release the “spring loaded” stamens from the petals and drum against the bee, releasing pollen onto its body before it visits another bloom. Next time you see a fresh mountain laurel bloom, wiggle your finger inside it to see the catapults in action!
NOT-SO-FUN FACT:
All parts of mountain laurel are toxic and can be fatal to humans and animals if ingested. Even honey made from bees that forage exclusively on mountain laurel is toxic, referred to as “Mad Honey.” Burning the wood creates smoke that can be poisonous to inhale.
GROWING CONDITIONS:
SOIL: Prefers rich acidic soils with good drainage. Appreciates mulch in the landscape to make sure roots stay moist and cool.
SUNLIGHT: Prefers morning sun and afternoon shade. Appreciates winter shade, especially in the southeast.
HEIGHT/WIDTH: Variable heights, expect cultivars to be shorter. In landscapes, the straight species mountain laurel slowly grows to an average height of 6-15’ (in 10 years time expect 4-8’ of growth). Uncommonly, it can reach up to 30’ tall on rich slopes of the Appalachian mountains.
ZONES: 4-9
We are starting off the season with the straight species mountain laurel as well as three different varieties. They all prefer the same growing conditions, and only vary in size, bloom colors, and other aesthetic characteristics:
K. latifolia (straight species)
Traditional mountain laurel will reach heights of 15’+ over time. Soft pink buds open to white blooms.
K. latifolia ‘Yankee Doodle’
Red flower buds open to irregular maroon banded blooms with a large white throat. Foliage is yellow green. Grows to 8-10’ tall and wide.
K. latifolia ‘Keepsake’
Raspberry red buds will open to purplish burgundy flowers with thin white edging. The new growth is reddish bronze and leaves mature to a glossy, deep blueish green. Dense rounded habit reaching 4-5’ tall and wide.
K. latifolia ‘Nathan Hale’
Red flower buds open pink. Symmetrical habit reaching 8’ tall and wide. Leaves are thick, shiny, and dark green. The petioles and stems of new growth are purplish red.