Mountain laurel
Kalmia latifolia
A native evergreen shrub of the eastern North American Appalachian + Piedmont understory producing extraordinary spring clusters of pink-to-white cup-shaped flowers with a unique spring-loaded pollination mechanism (anthers held under tension, triggered by visiting pollinators). State flower of Connecticut + Pennsylvania. Critically: NC State explicitly flags Kalmia as having HIGH-SEVERITY poison characteristics - all plant parts toxic to humans, dogs, cats, horses, and livestock; even honey from mountain-laurel nectar can poison humans ("mad honey").
Native: 25 US states
Climate fit: broad (87/100)
Structure
Pollinator
Focal point
Light
Full sun / Part sun / Part shade
Water
Moderate water
Mature size
4-15 ft tall · 6 ft apart
Hardy in zones
4a-9b
very cold to frosty winters
AHS heat range
1-11
Plant range authored in AHS heat-zone terms.
Native in Illinois
No
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Native across 25 US states and Canadian provinces - a wide-ranging part of North America's plant communities.
Cold hardiness
These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.
Now
Zone 6b
Plotwright
USDA Zone 6b
-5°F to 0°F
Well-suited
Zone 7a
Plotwright
0°F to 5°F
Well-suited
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
✓
Well-suited today and still thriving in 2050.
Heat tolerance
Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.
Loading AHS heat-zone data for this location...
Where this plant fits
Suitable across 42 ecoregions - 38 climate-resilient through 2070 · 1 suited today · 3 newly possible by 2070. Best matches first.
Similar plants
Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Educator packet
Plant packet
Mountain laurel educator packet
A native evergreen shrub of the eastern North American Appalachian + Piedmont understory producing extraordinary spring clusters of pink-to-white cup-shaped flowers with a unique spring-loaded pollination mechanism (anthers held under tension, triggered by visiting pollinators). State flower of Connecticut + Pennsylvania. Critically: NC State explicitly flags Kalmia as having HIGH-SEVERITY poison characteristics - all plant parts toxic to humans, dogs, cats, horses, and livestock; even honey from mountain-laurel nectar can poison humans ("mad honey").
Scientific name
Kalmia latifolia
Plant type
shrub
Hardiness
4a-9b
Light
full-sun, part-sun, part-shade
Moisture
moderate
Spacing
72 inches
Classroom prompts
- Which plant traits are observations, and which are care recommendations?
- How would this plant fit change if the garden location moved warmer, colder, wetter, or drier?
- Which source-backed facts would you cite in a lesson handout?
Use the Sources & citations section below for page citation styles and the field-level source list.
Sources & citations
Cite this page
For lesson plans, articles, or research that uses this page. Use the source cards below to explore the references that informed this record.
Plotwright. (2026, May 17). Mountain laurel (Kalmia latifolia). Retrieved 2026, August 20, from https://plotwright.com/plants/kalmia-latifolia
Sources used for this record
This record is compiled from the sources below.
Lady Bird Johnson Wildflower Center Native Plant Database
Botanical research database





