live oak health - Ask Extension
Several live oaks on my property are showing signs of distress. Originally I noticed it last year on a cluster of three in the front yard and now it'...
Knowledgebase
live oak health #790916
Asked May 15, 2022, 5:23 PM EDT
Several live oaks on my property are showing signs of distress. Originally I noticed it last year on a cluster of three in the front yard and now it's moved to an additional four or five in the backyard. The symptoms are leaf loss and dead clusters of tree growth at the ends of limbs. The picture attached is the most recent tree affected by this, it looked good up until the seasonal loss of leaves this year but it never grew back at the proper density.
I've had a couple arborists out to look at this, they both said it was not oak wilt and also said it wasn't that they weren't getting enough water. I had the original cluster of three deep fertilized last year, which perked them up a bit, but they're sill not where they should be if they were healthy.
Any suggestions on what to look at next would be appreciated.
Travis County Texas
Expert Response
A certified arborist who has been on site is really in the best position to assess the health of your trees. I would first heed their advice on what to do next.
That said, based on the symptoms you described, and the fact that you have eliminated lack of water as a possible cause, here are a few things to consider.
1. Overwatering or root rot will cause symptoms similar to lack of water. Girdling roots (https://agrilife.org/etg/2007/08/06/girdled_roots/) will also cause those symptoms.
2. Review what lawn and garden products/treatments you are using. Weed and feed products in particular can be toxic to trees.
3. It's hard to tell from the picture how much of the tree is affected. If it is 10% of the branches or less, it could simply be natural aging/renewal. Careful pruning should help. However, please note that you should never prune oak trees between Feb-June inclusive, because that is when the sap beetles that carry oak wilt are active. When pruning, paint all cuts regardless of the time of year. Better yet, engage your arborist to do this for you.
4. Stress from the 2021 freeze. Many of our plants are still recovering and it may take a few years to realize the full effect that it had on our landscapes.
Please also see: https://www.austintexas.gov/sites/default/files/files/Watershed/growgreen/factsheets/TreeCare.pdf
That said, based on the symptoms you described, and the fact that you have eliminated lack of water as a possible cause, here are a few things to consider.
1. Overwatering or root rot will cause symptoms similar to lack of water. Girdling roots (https://agrilife.org/etg/2007/08/06/girdled_roots/) will also cause those symptoms.
2. Review what lawn and garden products/treatments you are using. Weed and feed products in particular can be toxic to trees.
3. It's hard to tell from the picture how much of the tree is affected. If it is 10% of the branches or less, it could simply be natural aging/renewal. Careful pruning should help. However, please note that you should never prune oak trees between Feb-June inclusive, because that is when the sap beetles that carry oak wilt are active. When pruning, paint all cuts regardless of the time of year. Better yet, engage your arborist to do this for you.
4. Stress from the 2021 freeze. Many of our plants are still recovering and it may take a few years to realize the full effect that it had on our landscapes.
Please also see: https://www.austintexas.gov/sites/default/files/files/Watershed/growgreen/factsheets/TreeCare.pdf
Thank you for the quick reply.
I have some additional info that may or may not be relevant.
I was removing root suckers on the trunk and lower branches and saw what appears to be some kind of insect infestation. about half the suckers I removed had insect web nesting material on the leaves. I've attached two pictures. The insect may or may not be related to the nest, but it crawled from the sucker so I took the picture.
thanks.
Here's the bug pic.
Unless you have seen insect damage over the rest of your trees, it's probably not related. Please also be aware that unless you have spider mites (https://agrilife.org/urban-ipm/2015/08/07/spider-mites/#:~:text=Avoid%20spider%20mites%20by%20reducing,problem%20after%20they%20are%20used.), most spiders that generate webbing are beneficial, rather than harmful.
