Hemlock trees difficulty

Asked May 4, 2019, 2:02 PM EDT

I have 7 Eastern Hemlock trees in my yard and am noticing needle death on all of them, some much worse than others. They are between 6 and 20 feet tall. I have been very cognizant of the effects of Hemlock Wolly Adelgid and check the trees often for signs. I do not see any evidence of them, however there is significant needle drop on one of my trees with sparse needle drop or moisture deficiency on even the healthiest specimens. The moisture deficiency is the exact same on all of the unhealthy needle I see, where the needle is browning from the distal end in toward the base of the needle where it connects to the branch. Is there any other common pest I should be looking for to save thee trees? Do you have any suggestions?

Allegan County Michigan trees and shrubs evergreens conifers

3 Responses

Hello. Can you tell me how recently the trees were planted? And when did you begin observing the problem? Before noticing the needle discoloration I noticed the mulch going right up to the bark of the trunk. Mulch should stop two or three inches away from the trunk. The trees could be experiencing stress due to winter injury and planting problems. If the trees were planted too deeply (the root flare should be visible at the soil line) there could also be girdling roots or secondary roots. I will do more research on possible diseases and get back to you.

Thanks so much for the reply. I transplanted the 3 smallest specimens 2 years ago in the late fall, and they all had a good recovery up until now. Last year, they all had new growth in the spring, albeit a bit stunted, which I expected. I noticed the needle drop on the worst specimen just 3 days ago, but it has likely been going on for a few weeks. I did remulch the root area last fall at about 2" deep. I will be sure to remove the mulch from the trunk like you suggested. The worst specimen, along with 2 other specimens that look much healthier, are about equidistant from the road and could potentially have some stress from road salt spray, however they've not had any negative response from previous winters.

I have not seen any specific diseases that look like what you are experiencing which makes me think it is an abiotic problem- environmental stress. Clean away the mulch, dig down a bit to see where the root flare is and water thoroughly by placing a hose running slowly at the base of the tree. You could also consult a certified arborist in your area.