Half of my mountain laurel leaves turned yellow in a week - Ask Extension
Hello, I'm hoping you can help me understand what has happened to my beautiful tree. I have what my neighbor says is a mountain laurel that has multip...
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Half of my mountain laurel leaves turned yellow in a week #815439
Asked October 28, 2022, 2:31 PM EDT
Hello, I'm hoping you can help me understand what has happened to my beautiful tree. I have what my neighbor says is a mountain laurel that has multiple trunks. The leaves on the largest trunk, the one in front and facing the street, suddenly turned yellow and the branches are dry, within a matter of days. (first two pictures - is this a fungus?) The tree right next to it is still green (last picture attached.)
We don't apply any herbicides or fertilizer to our lawn or the tree. It gets watered twice a week overnight with the rest of the plants in that bed. We did notice that the part that died didn't have blossoms this year, while other trees on our street did. What could have caused this sudden death? Is there a way to test the branches that I cut off?
Thank you,
Kristi Anglade
Travis County Texas
Expert Response
Hi Kristi,
It is difficult to identify the cause. I have copied a section from Texas A&M on mountain laurels followed by the link to that page.
Good drainage is a must, as is frequent monitoring for "the worm", the Genista moth larvae which can decimate the foliage in a few days, and is its primary pest.
https://aggie-horticulture.tamu.edu/ornamentals/nativeshrubs/sophorasecund.htm
I lost two of my mountain laurels after winter storm Uri. If your loss was not herbicides, or insect invasion that you would have noticed, my educated guess is that that tree was stressed considerably, possibly by winter storm Uri. I suspect this as it did not flower as it normally would.
Mountain laurels bloom early in the year. Since their vascular system is more active earlier in the year, it is more susceptible to freeze damage. The tree may survive but struggles to thrive and eventually we may experience branch die back.
The plant disease lab at Texas A&M was making some changes and seems to be taking samples again. You will need to contact them to get the specifics of how to register and submit samples. Here is the link:
https://plantclinic.tamu.edu
Wishing you all the best!
Bob Kunkel
It is difficult to identify the cause. I have copied a section from Texas A&M on mountain laurels followed by the link to that page.
Good drainage is a must, as is frequent monitoring for "the worm", the Genista moth larvae which can decimate the foliage in a few days, and is its primary pest.
https://aggie-horticulture.tamu.edu/ornamentals/nativeshrubs/sophorasecund.htm
I lost two of my mountain laurels after winter storm Uri. If your loss was not herbicides, or insect invasion that you would have noticed, my educated guess is that that tree was stressed considerably, possibly by winter storm Uri. I suspect this as it did not flower as it normally would.
Mountain laurels bloom early in the year. Since their vascular system is more active earlier in the year, it is more susceptible to freeze damage. The tree may survive but struggles to thrive and eventually we may experience branch die back.
The plant disease lab at Texas A&M was making some changes and seems to be taking samples again. You will need to contact them to get the specifics of how to register and submit samples. Here is the link:
https://plantclinic.tamu.edu
Wishing you all the best!
Bob Kunkel
