Troubleshooting
mountain laurel problems — and how to fix them
mountain laurel (Kalmia latifolia) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Leaf scorch and yellowing
Caused by alkaline soil (pH too high), drought, or root damage. Test soil pH and remediate with sulphur if above 5.5. Yellowing with green veins indicates iron chlorosis — treat with chelated iron and lower pH.
Lace bugs (Stephanitis pyrioides)
Tiny insects that stipple the upper leaf surface silver-grey while leaving black frass on the undersides. Infestations worsen in sunny, stressed plants. Treat with insecticidal soap or neem oil; improve moisture and shade conditions.
Borer damage
Rhododendron borers (Synanthedon rhododendri) can tunnel into stems, causing wilting and dieback of branches. Prune out and destroy infested stems promptly. Maintaining plant vigour through proper watering and acidic soil reduces susceptibility.
Prevent mountain laurel problems before they start
Most mountain laurel issues are care-mismatch, not bad luck. Dial in the basics:
Looking for mountain laurel in general rather than its problems? Read the full mountain laurel care guide — light, water, soil and feeding.
mountain laurel problems — FAQ
Why is my mountain laurel leaf scorch and yellowing?
Caused by alkaline soil (pH too high), drought, or root damage. Test soil pH and remediate with sulphur if above 5.5. Yellowing with green veins indicates iron chlorosis — treat with chelated iron and lower pH.
Why is my mountain laurel lace bugs (stephanitis pyrioides)?
Tiny insects that stipple the upper leaf surface silver-grey while leaving black frass on the undersides. Infestations worsen in sunny, stressed plants. Treat with insecticidal soap or neem oil; improve moisture and shade conditions.
Why is my mountain laurel borer damage?
Rhododendron borers (Synanthedon rhododendri) can tunnel into stems, causing wilting and dieback of branches. Prune out and destroy infested stems promptly. Maintaining plant vigour through proper watering and acidic soil reduces susceptibility.