Kalmia latifolia, commonly called mountain laurel, is a gnarled, multi-stemmed, 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, mountain slopes and woodland margins. It is noted for its excellent spring flowers and quality year round foliage. It typically grows as a dense rounded shrub to 5-15’ tall, opening up and developing gnarly branches with age. 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 30’ tall. Flowers appear in clusters (corymbs to 6” across), 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. Flowers give way to non-showy brown fruits (3/16” dehiscent capsules) that persist into winter. Elliptic, alternate, leathery, glossy evergreen leaves (to 5” long) are dark green above and yellow green beneath and reminiscent to the leaves of rhododendrons. All parts of this plant are toxic if ingested. Kalmia latifolia is the state flower of Connecticut and Pennsylvania. Superior flowering shrub for groups or massing in shrub borders, cottage gardens, woodland areas or wild/naturalized areas. Hedge. Foundations. Compliments rhododendrons and azaleas. 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. Hardy in zones 4-9.
Growing Instructions for the Mountain Laurel
The seeds have a period of dormancy. They can be planted outdoors in the fall or winter for spring germination or they can be cold stratified to simulate winter conditions and to break their dormancy at any time of the year. 1. Soak the seeds in water for 24 hours. 2. Put the seeds in a ziplock bag. 3. Put the bag in the refrigerator and leave it there for 2 months. 4. The seeds like moist, well-drained soil. Put some potting soil in a container. 5. Sow the seeds on the surface of the soil. The seeds need light to germinate. 6. Water the soil so that it is moist but not wet. The seeds may take2-4 weeks to germinate. 7. When the seedlings are a few inches tall, they can be transplanted.