How to Plant and Grow Mountain Laurel

A showy shrub native to eastern North America, from southern Maine to Louisiana and northern Florida, mountain laurel is closely related to azaleas and rhododendrons. It is the most prolific species in the Kalmia genus, forming dense thickets in wooded areas and woodland margins, in meadows, and on mountain slopes. It grows in a large, rounded, dense mound, sometimes as a small tree. The dark green foliage remains on the plant all year. Old branches are often contorted, cracked, or crooked. In late spring or early summer depending on the region, it bears clusters of flowers in white, pink, and red. The individual florets are shaped like inverted parasols with markings ranging in color from cinnamon, to scarlet, rose, or burgundy.

Mountain laurel has been a popular ornamental since the early 18th century. It made its way to England and was bred there before being reintroduced to the United States. Today there are more than 75 cultivars of mountain laurel.

The plant is toxic to humans and pets. If honeybees feed on the flowers, the honey is also toxic.

Where to Plant Mountain Laurel

A location in dappled sun or partial shade is best, as the shrub thrives in moist, acidic soil—in sunny locations, the soil dries out faster.

Use this flowering shrub as an accent in a native landscape, butterfly, or pollinator garden. In meadows, naturalized, or woodland areas, plant it in clusters to mimic the way it grows in it s natural habitats. Dwarf varieties of mountain laurel make good container plants.

The plant has a high flammabilty rating so plant it at a safe distance from your home.

How and When to Plant Mountain Laurel

Plant mountain laurel between early spring and early summer. Dig a hole at least twice the size of the root ball and just as deep. Place the shrub in the hole and backfill with the original soil so that the top of the root ball is flush with the soil and tamp down the soil. Water it well and continue to water it regularly during the first growing season in the absence of rain to encourage a strong root system.

Space the shrubs at least 6 feet apart, depending on the variety. Dwarf varieties or mass plantings can be spaced as little as 4 feet apart.

Mountain Laurel Care Tips

Even in optimal conditions and with the best care, the shrub is naturally a slow grower so don’t worry if you don’t see a considerable increase in size every year.

Light

While mountain laurel tolerates full sun in moist soil, it does better in partial or dappled shade where the soil is less prone to drying out.

Soil and Water

Like most rhododendrons and azaleas, mountain laurel needs soil with an acidic pH, between 5.0 to 5.5 is ideal. It flourishes in soil that is moist, well-drained, and high in organic matter, so amend average soil with compost or peat moss before planting. Apply a 2-inch layer of mulch around the base of the shrub to conserve soil moisture.

Temperature and Humidity

The shrub is adapted to a fairly large temperature range, from cold, snowy winters at the lower and of its zone range, to hot summers in more southern locations if grown in partially shaded locations. It tolerates a hot, humid climate but not hot arid conditions.

Fertilizer

Once a year, when new growth starts in the spring, feed the plant a slow-release fertilizer for acid-loving plants. Don't let the fertilizer touch the trunk and be careful not to overfertilize; it won't trigger speedier growth.

Pruning

After the bloom, remove the spent flowers or seed heads, which triggers the growth of new shoots. If your mountain laurel has a dense, rounded growth habit, it is usually not necessary to prune it other than to remove dead, broken, or diseased branches. If the shrub is leggy, prune it in the late winter to encourage a more compact growth. Cut the tallest branch back to the height of the other branches and remove any weak, late-season growth.

Potting and Repotting

If you want to grow mountain laurel in a container, select a dwarf variety. Use a container of at least 24 inches in diameter to accommodate its root system and make sure it has large drainage holes. Use potting mix for acid-loving plants.

During the winter, keep the container outdoors but if you live in an area with freezing cold winters, the roots are insufficiently insulated against the winter cold, unlike in garden soil. Either place the pot in a larger container and fill it with sand or mulch to create a planting silo, or wrap the container in several layers of insulating material such as burlap, bubble wrap, or geotextiles for insulation.

Because mountain laurel grows slowly, it will only require repotting every few years when the root system has filled the pot.

Pests and Problems

Mountain laurel attracts borers, scale insects, white flies, and lace bugs. Potential diseases include leaf spots and blights. 

How to Propagate Mountain Laurel

Mountain laurel is best propagated from cuttings in the summer. Take a 6-inch cutting of new growth and remove the bottom leaves. At the bottom of the cutting, slice off two slivers of bark, about 1 to 1.5 inches in length, on opposite sides. Dip the bottom of the cutting in rooting hormone and insert it in a 4-inch pot filled with potting mix, deep enough so that the nicked portion is completely buried. Keep the cutting evenly moist in a location out of direct sunlight. Rooting takes 4 to 6 months. During the winter, to protect the roots from the cold, bury the pot in the ground or insulate it like you would a potted mountain laurel.

Types of Mountain Laurel

'Elf' Mountain Laurel

'Elf' was the first dwarf mountain laurel introduced. It has large pink buds that open to nearly white flowers. It grows 3 feet tall and 4 feet wide.

'Minuet' Mountain Laurel

This outstanding dwarf selection bears light pink buds and pink flowers with a bold red band. It grows 3 feet tall and wide.

'Olympic Fire' Mountain Laurel

'Olympic Fire' shows off red-pink buds that open to dark pink flowers. It grows 10 feet tall and wide.

'Peppermint' Mountain Laurel

'Peppermint' offers unique white flowers with dark red streaks running to the edges. It grows 10 feet tall and wide.

'Snowdrift' Mountain Laurel

Considered one of the best pure-white selections, 'Snowdrift' has rich, dark green foliage that's very shiny. It grows 10 feet tall and wide.

'Tinkerbell' Mountain Laurel

This dwarf selection bears deep pink buds that open to reveal rich pink flowers. It grows 3 feet tall and wide.

Mountain Laurel Companion Plants

Solomon's Seal

With its arching stems, Solomon's seal adds an architectural component to garden beds. The stems of this classic shade garden plant are lined with small, bell-shaped, white blooms in the spring. These blossoms later give way to bluish-black berries that wildlife love. The spreading and clumping habit of this plant makes it an excellent groundcover for shady spots. Zone 3-9

Goatsbeard

The fernlike foliage and wispy white blooms of goatsbeard lend airiness to gardens and look especially stunning en masse. Its flowers attract butterflies and bees. Goatsbeard plants like part shade and need shelter from the hot afternoon sun. They can only tolerate full sun in the northern range of their hardiness. Zone 3-8

Wintergreen

Wintergreen overflows with interest year-round. This perennial evergreen makes a colorful groundcover around shade-loving shrubs for a low-maintenance garden. The attractive leaves are paired with white flowers in summer and bright red berries and reddish-bronze foliage in fall. Standing just 4 to 8 inches tall, it hugs the ground, choking out weeds while creating a dense mat of glossy foliage. Zone 3-8