Hemlock Needles Falling Off - Ask Extension
This Eastern Hemlock was planted last spring. It looked fine all summer, fall, and winter. We noticed some needle drop this spring, and it is progre...
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Hemlock Needles Falling Off #565245
Asked May 28, 2019, 4:26 PM EDT
This Eastern Hemlock was planted last spring. It looked fine all summer, fall, and winter. We noticed some needle drop this spring, and it is progressing quite rapidly, although the branches that are not affected contain new growth. I don't see evidence of wooly adelgid, rust, etc. on the existing needles. The hole in which the tree was planted was larger than the root ball, and to the best of our recollection we put topsoil in the hole before planting the tree. The soil in the yard contains considerable clay. Let me know if you have thoughts on potential causes and remedies. Thanks very much.
Wayne County Michigan
Expert Response
Appears serious. Can't diagnose from this vantage point as there are a number of possible reasons. Hemlocks don't tolerate poor drainage well and the clay soil that does not include a way for excess water to drain off could be an issue. Hemlock Wooly Adelgid is of major concern in Michigan but you say no to that. https://www.canr.msu.edu/news/losing_most_of_michigans_eastern_hemlock_resource_is_a_real_possibility
But there are other potential pests and diseases. Here are specs for hemlock:
https://www.mortonarb.org/trees-plants/tree-plant-descriptions/eastern-hemlock
Note this passage from the above: Disease, pests, and problems Several possible disease and insect pests including hemlock scale, bagworm, needle rust mite, woolly adelgid and needle blight. Susceptible to winter burn if not sheltered from strong winds.
Like all evergreens, hemlocks are subject to desiccation, drying winter winds termed above as winter burn. They do not go dormant in winter and there can be no moisture uptake from frozen soil, with winter winds drying moisture within the plant. This is why all evergreens should be thoroughly hydrated going into winter. Record cold temps this past winter could also be a factor. Damage appears to be more concentrated however, as in insect/disease activity and best suggested to have the tree examined by a Certified Arborist, one who specializes in everything woody. You can find one or more Certified Arborists in your zip code at
www.treesaregood.com Click on the Find an Arborist tab. Arborist evaluations are not expensive and the best way to get the needed positive diagnosis.
Good luck!
But there are other potential pests and diseases. Here are specs for hemlock:
https://www.mortonarb.org/trees-plants/tree-plant-descriptions/eastern-hemlock
Note this passage from the above: Disease, pests, and problems Several possible disease and insect pests including hemlock scale, bagworm, needle rust mite, woolly adelgid and needle blight. Susceptible to winter burn if not sheltered from strong winds.
Like all evergreens, hemlocks are subject to desiccation, drying winter winds termed above as winter burn. They do not go dormant in winter and there can be no moisture uptake from frozen soil, with winter winds drying moisture within the plant. This is why all evergreens should be thoroughly hydrated going into winter. Record cold temps this past winter could also be a factor. Damage appears to be more concentrated however, as in insect/disease activity and best suggested to have the tree examined by a Certified Arborist, one who specializes in everything woody. You can find one or more Certified Arborists in your zip code at
www.treesaregood.com Click on the Find an Arborist tab. Arborist evaluations are not expensive and the best way to get the needed positive diagnosis.
Good luck!
Thanks very much, John.
