Hemlock lost 95% of needles in a few days - Ask Extension
Our beloved Hemlock that we planted in 2020 has lost nearly all its needles. It appeared very healthy just a few days prior. It was just today (after ...
Knowledgebase
Hemlock lost 95% of needles in a few days #853066
Asked October 13, 2023, 4:38 PM EDT
Our beloved Hemlock that we planted in 2020 has lost nearly all its needles. It appeared very healthy just a few days prior. It was just today (after the heavy rains in Eugene) that my husband discovered it bald. There are mushrooms growing in the soil where it is planted year round, we built up the area with good soil prior to planting. It's had zero browning or pest issues. It went from green and healthy to this (see photo).
Thank-you in advance for any assistance you can provide.
Lane County Oregon
Expert Response
it is hard to say what might have gone wrong. Trees are highly susceptible to issues the first three years after planting. Hemlock are particularly susceptible to drought. Was the tree watered in the summer? Is there damage at the base? It looks like the dirt was mounded up to the stem, is that the case, or is the tree planted on a slight hill? Unfortunately with that much foliage loss the tree likely will not make it.
It was irrigated, it is on a small hill we built up, with good soil. No damage at the base.
It dropped these needles without any signs of stress, all at once. The needles are all green on the ground. Is there a way to test the soil or tree for potential damage chemical or disease? Its just so bizarre, I'd like to rule out herbicide or power wash solution. I will attach more photos below.
There are some needles left on the right side of the tree (2nd photo).
Thank-you.
Sorry for taking so long to respond I was discussing possibilities with my colleagues and other partners. The short answer is, this is not typical and is not something that is a direct symptom of something biological. We've considered various diseases and insect possibilities and none of them fit the symptoms. As I mentioned in my first answer, hemlock are very sensitive trees and can have issues if things aren't just right. This looks like a large tree that was planted only a few years ago which makes them more sensitive to transplant shock. This response seems to be a shock response because the needles didn't turn brown.
Here are a few suggestions that you might consider if you think is is more than planting shock. I'll leave it up to your experience with the tree to make the decision. Conifers can be easily overwatered, this doesn't exactly match since it usually causes needles to brown and drop from the top down, but could be a possibility. This looks like a large tree that was planted only a few years ago. Hopefully you took it out of any pot or burlap covering, if not the roots may have gotten bound and drowned from the watering. There is a possibility of chemical exposure. Usually it would cause the needles to turn brown first, but it could be possible.
I apologize we don't have a definite answer for you. OSU does have a fee based plant clinic on campus you can send a sample to if you feel like you have to have more answers. Here is the website for that. https://bpp.oregonstate.edu/plant-clinic.
Here are a few suggestions that you might consider if you think is is more than planting shock. I'll leave it up to your experience with the tree to make the decision. Conifers can be easily overwatered, this doesn't exactly match since it usually causes needles to brown and drop from the top down, but could be a possibility. This looks like a large tree that was planted only a few years ago. Hopefully you took it out of any pot or burlap covering, if not the roots may have gotten bound and drowned from the watering. There is a possibility of chemical exposure. Usually it would cause the needles to turn brown first, but it could be possible.
I apologize we don't have a definite answer for you. OSU does have a fee based plant clinic on campus you can send a sample to if you feel like you have to have more answers. Here is the website for that. https://bpp.oregonstate.edu/plant-clinic.
