Several Established Mountain Laurel Trees are Dropping All Their Leaves! - Ask Extension
We are blessed with dozens of native Mountain Laurel trees of various sizes that had been doing very well for decades with no help from us, but all of...
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Several Established Mountain Laurel Trees are Dropping All Their Leaves! #301058
Asked February 14, 2016, 4:59 PM EST
We are blessed with dozens of native Mountain Laurel trees of various sizes that had been doing very well for decades with no help from us, but all of a sudden several of the trees in one area are dumping their leaves.
The leaves first get spotty, then they just drop off. We have NEVER watered the area and nothing drains into it. We have never used any herbicides or even insecticides there. The only thing happening nearby horticulturally is that two large Live Oak trees are dying of Oak Wilt, but no branches have fallen from the oaks yet.
The sick Mountain Laurels have no visible worms or webs at all, just spotty leaves that drop off. We thought Mountain Laurels were pretty much immune to most diseases, but ours are VERY sick all of a sudden. Any thoughts?
Thanks!
The leaves first get spotty, then they just drop off. We have NEVER watered the area and nothing drains into it. We have never used any herbicides or even insecticides there. The only thing happening nearby horticulturally is that two large Live Oak trees are dying of Oak Wilt, but no branches have fallen from the oaks yet.
The sick Mountain Laurels have no visible worms or webs at all, just spotty leaves that drop off. We thought Mountain Laurels were pretty much immune to most diseases, but ours are VERY sick all of a sudden. Any thoughts?
Thanks!
Hays County Texas
Expert Response
You are correct in that Mountain Laurels are a very hardy plant. While they are hardy, they are still prone to a few potential problems. You can rest assured, however, that this problem is NOT associated with the Oak Wilt that is affecting your nearby oaks.
It is possible that the leaves do not have enough chlorophyll, which can cause the leaves to becomes chlorotic. This can cause black spotting between the veins of the leaves. Plants can become chlorotic because the soil in which they are growing is so alkaline that the plant has difficulty extracting the iron that it needs from the soil.
The spotting can also be caused by a fungus. The spots on the leaves can run together and cause the leaves to fall prematurely. Cool, moist weather encourages these diseases, especially when new leaves are developing. Shake out all fallen and diseased leaves from the center of each laurel shrub and destroy them. Remove all dead branches in the center of individual plants or hedges to allow better aeration. Mulching helps prevent the disease from splashing up from the ground and infecting plants. Spray at weekly to 10-day intervals with sulfur or copper fungicide, particularly in rainy weather. Dig up and discard seriously infected shrubs together with the root system and soil ball.
It is possible that the leaves do not have enough chlorophyll, which can cause the leaves to becomes chlorotic. This can cause black spotting between the veins of the leaves. Plants can become chlorotic because the soil in which they are growing is so alkaline that the plant has difficulty extracting the iron that it needs from the soil.
The spotting can also be caused by a fungus. The spots on the leaves can run together and cause the leaves to fall prematurely. Cool, moist weather encourages these diseases, especially when new leaves are developing. Shake out all fallen and diseased leaves from the center of each laurel shrub and destroy them. Remove all dead branches in the center of individual plants or hedges to allow better aeration. Mulching helps prevent the disease from splashing up from the ground and infecting plants. Spray at weekly to 10-day intervals with sulfur or copper fungicide, particularly in rainy weather. Dig up and discard seriously infected shrubs together with the root system and soil ball.
