Hemlock tree - browning of foliage - Ask Extension
I recently noticed patches of browning of foliage in my hemlock trees. Attached are photos taken two days ago. Your advice will be appreciated.
Knowledgebase
Hemlock tree - browning of foliage #885352
Asked September 15, 2024, 9:28 PM EDT
I recently noticed patches of browning of foliage in my hemlock trees. Attached are photos taken two days ago. Your advice will be appreciated.
Howard County Maryland
Expert Response
It is difficult to tell from you photos what the issue is. How much of the tree is affected?
The biggest thing to look for is a serious pest that kills Eastern Hemlock over a number of years called Hemlock Woolly Adelgid. You can see what it looks like and learn more here:
https://extension.umd.edu/resource/hemlock-woolly-adelgid-trees/
If you see that, we recommend having the tree treated for it, which must be done by an individual who is a professional pesticide applicator, certified by the MD Dept. of Agriculture. (Only certified applicators can get and apply the pesticide needed. The chemical can harm pollinators that visit flowers on treated plants but since these trees are wind-propagated, it is not of concern).
If the tree is important to you, we'd recommend an on-site visit by a tree health expert, a.k.a. a certified arborist, for an assessment. Most larger tree companies have ISA-certified arborists on staff or you can search for one at the credentialing agency at http://www.treesaregood.org
Christine
The biggest thing to look for is a serious pest that kills Eastern Hemlock over a number of years called Hemlock Woolly Adelgid. You can see what it looks like and learn more here:
https://extension.umd.edu/resource/hemlock-woolly-adelgid-trees/
If you see that, we recommend having the tree treated for it, which must be done by an individual who is a professional pesticide applicator, certified by the MD Dept. of Agriculture. (Only certified applicators can get and apply the pesticide needed. The chemical can harm pollinators that visit flowers on treated plants but since these trees are wind-propagated, it is not of concern).
If the tree is important to you, we'd recommend an on-site visit by a tree health expert, a.k.a. a certified arborist, for an assessment. Most larger tree companies have ISA-certified arborists on staff or you can search for one at the credentialing agency at http://www.treesaregood.org
Christine
