Mountain laurel (Kalmia latifolia) is a flowering broadleaf evergreen shrub with a multistemmed growth habit. It has beautiful spring blooms, and its elliptical, glossy deep-green leaves (resembling those of rhododendrons) and gnarled stems make it attractive in all seasons. This shade-loving shrub produces clusters of rose, pink, or white flowers with purple markings in late May to early June. If the flowers are not deadheaded, nondescript brown fruits will appear. Many different cultivars are available that offer various sizes and bloom colors.
Mountain laurel is a relatively slow-growing shrub that grows dense and round, adding about one foot per year. While mountain laurel is particular about its soil needs, this plant is easy to grow in the right environment. It is a good flowering shrub for mass plantings in shady shrub borders, woodland gardens, or foundation plantings. It partners well with rhododendrons and azaleas.
Mountain laurel is native to the eastern United States, from New England south to the Florida panhandle and west to southern Indiana down to Louisiana.
Mountain laurels are beautiful evergreen shrubs that are beloved for their gorgeous star-shaped flowers and attractive foliage. While mountain laurels are relatively low maintenance plants properly pruning them is important to maintain their health and maximize their beauty. Here is a complete guide on when and how to prune mountain laurels for optimal growth.
When to Prune Mountain Laurels
The best time to prune mountain laurels is in early spring, right after they have finished flowering. Pruning at this time allows the shrub to produce new growth through the spring and summer before going dormant for winter. It also removes spent blooms, which promotes better flowering for next season.
Pruning mountain laurels in early spring gives the shrubs the entire growing season to recover before cold weather returns. It is generally recommended to avoid pruning mountain laurels in summer or winter when growth has slowed. However, dead damaged or diseased branches can be removed at any time if necessary.
How Often Mountain Laurels Need Pruning
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Young mountain laurel shrubs may only need light pruning for shaping and thinning out growth every 2-3 years as the plants mature.
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Established, mature mountain laurels can often go years without needing pruning.
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However, it is a good idea to evaluate mountain laurel shrubs each spring after blooming and prune as needed to maintain their health and form.
Pruning Tools Needed
Having the proper pruning tools makes pruning mountain laurels much easier. Here are the tools you’ll need:
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Bypass hand pruners for cutting back smaller stems and branches.
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Loppers for thicker branches up to about half inch diameter.
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Pruning saw or bow saw for cutting back large, old branches or rejuvenation pruning.
Always use clean, sharp pruning tools to make smooth cuts without crushing or tearing the branches. Dull tools can damage the shrub. It’s also important to disinfect tools between each cut when removing diseased wood to prevent spreading issues further.
How to Prune Mountain Laurels
Follow these steps when pruning mountain laurel shrubs:
1. Remove Dead, Diseased, or Damaged Branches
The first priority when pruning mountain laurels is to remove any dead, diseased, or damaged wood. Cuts should be made just outside of the affected area, into healthy tissue. Disinfect tools after each cut to prevent introducing disease. Removing dead or damaged branches opens up the interior to allow better light and air movement.
2. Cut Out Overgrown Old Wood
Next, look for older branches that are either overgrown or declining in vigor. These can be cut back all the way to the ground to encourage the emergence of new, healthy shoots. Mountain laurels respond very well to rejuvenation pruning of this kind, so don’t be afraid to prune hard when needed.
3. Thin Excess Growth in Center
If the shrub has become overcrowded, selectively thin out stems originating from the interior of the plant. This relieves congestion and allows better airflow and light penetration into the middle of the shrub. Also remove any branches with narrow crotch angles that may be prone to damage. As a general rule, removing about 1/3 of the oldest branches helps rejuvenate overgrown mountain laurels.
4. Shape and Contain Size
Finally, step back to assess and correct the overall shape and size of the shrub. Trim back wayward, asymmetric growth to shape the canopy. Remove selected branches to reduce the size if the mountain laurel has outgrown its space. Avoid shearing off the top; instead make selective cuts to branches.
Pruning Tips for Mountain Laurels
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Never remove more than 1/3 of the total branches when pruning mountain laurels to avoid shock.
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Fertilize after pruning to encourage rapid regrowth. Use acidic fertilizers formulated for ericaceous plants like mountain laurels.
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Watch for signs of pests or disease following pruning and take corrective action if needed.
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Water mountain laurels during dry periods after heavy pruning.
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Avoid heavy pruning during winter or summer months. Only remove dead/damaged branches then.
Signs Your Mountain Laurel Needs Pruning
Here are signs that your mountain laurel would benefit from rejuvenation pruning:
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Declining flower production
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Congested, overgrown growth
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Excessive dieback in older branches
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Interior leaves turning brown
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Dead, crossing, or damaged branches
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Shrub has outgrown its allotted space
With proper pruning timing and technique, mountain laurels can thrive for decades. Follow these mountain laurel pruning guidelines to keep your shrubs healthy, looking their best, and flowering abundantly year after year.
Types of Mountain Laurel
Mountain laurel cultivars offer various color options, including many that are bicolored. Most are four to six feet tall, but several dwarf cultivars will reach just three feet in height. The European Kalmia Society provides a full list of cultivars; these are some of the most popular choices:
- K. latifolia Elf: This cultivar has white flowers and grows to just three feet tall and wide.
- K. latifolia Minuet: This cultivar flowers with white centers speckled with cherry red markings and surrounded by cherry-red margins. It reaches a mature size of just three feet tall and wide.
- K. latifolia Olympic Fire: This shrub has red-pink buds that open to dark pink flowers; it grows 10 feet tall and wide.
- K. latifolia Peppermint: The flowers have red stripes that radiate from the flower center out to the edges of the petals, resembling hard peppermint candies. It grows 10 feet tall.
- K. latifolia Firecracker: This cultivar tops out at three feet in height and has intense red-colored buds that open white and then turn to light pink.
- K. latifolia Sarah: Blooms in late spring with red buds that open to become rich pink to coral color with dots on the petals. A slow-grower reaching four to five feet and ideal for hedges.
Fertilizer
This shrub should be fed in spring with an acid fertilizer, such as one formulated for azaleas and rhododendrons. Feeding will encourage more vigorous blooming. For the amount, follow the instructions on the fertilizer label.
What You Should Know About The Mountain Laurel Plant | Mountain Laurel Plant Care Guide
FAQ
When should you prune mountain laurel?
Mountain laurel requires little pruning. Dead or broken branches can be removed at any time. Shaping pruning should be done in the spring, just after blooming is completed. Spent flower clusters should be deadheaded after the blooms fade.
What is the best time to prune laurel?
When to prune a Laurel Hedge. The best time to prune laurel is late winter or early spring before any new growth begins. This allows pruning cuts to heal quickly and encourages vigorous new growth during the growing season.
Should I deadhead my mountain laurel?
An individual mountain laurel shrub can produce thousands of seeds annually. It’s a good idea to pinch off spent flowers so the plant can put its energy into next year’s blooms instead of reproduction. Deadheading also helps to prevent legginess.
Is it illegal to cut mountain laurel?
It is against the law to remove them in the wild in CT, but on my property I am allowed to do it. If I don’t remove them, the entire yard will be covered with mountain laurel. I have several volunteers in the yard, here is a smaller one with its show after the shading tree was removed.