Mountain laurel
Kalmia latifolia · Ericaceae
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around mountain laurel and prepare for winter.
ID card
- Foliage
- Evergreen
- Blooming
- Spring (April-May)
- Adult size
- 4.9 to 9.8 feet tall and wide
- Growth
- Slow to moderate
- Hardiness
- -13 to -4 °F
- Origin
- Eastern North America
- Soil type
- Acidic, rich in organic matter
- Exposure
- Partial shade to light shade
Care
Regular and moderate watering
Kalmia prefers constantly moist but well-drained soil. Water generously in spring and summer, especially during dry spells, while avoiding excess that promotes root rot. In winter, reduce watering but don't let the soil dry out completely.
Ideal partial shade
Broadleaf kalmia thrives in partial shade or light shade, sheltered from strong drying winds. Too intense direct sun can scorch the foliage and reduce flowering. A protected spot near taller trees is particularly beneficial.
Acidic and rich soil
This plant requires acidic soil (pH 4.5 to 5.5) and well-structured composition. Enrich the soil with peat, leaf mold, or compost when planting. Good drainage remains essential to prevent root suffocation.
Light pruning after flowering
Remove spent flowers after blooming to encourage better branching the following year. Avoid severe pruning; since kalmia has naturally compact growth, only dead or poorly positioned branches merit cutting. Prune lightly in late spring.
Moderate fertilizing
Apply fertilizer for acid-loving plants once or twice in spring and early summer. Avoid excess nitrogen, which encourages foliage at the expense of flowering. Prefer gradual feeding rather than heavy applications.
Rare pests and diseases
Kalmia is generally robust. However, watch for spider mites in dry conditions and scale insects under stress. Regular watering and good air circulation limit these risks. Avoid stagnant moisture that would promote fungal issues.
Did you know?
Broadleaf kalmia is the official state flower of Connecticut since 1907. Its remarkably geometric, star-shaped pink or white flowers conceal a fascinating botanical secret: the stamens are tensioned like springs and snap suddenly when touched by pollinating insects, projecting pollen with remarkable precision.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
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Tips generated and checked by Viridia — adapt them to your local climate.