Has anyone experienced a Live Oak Tree shedding parts of the canopy's leaves in July? Two trees, which happen to be some of the closest to my house, are turning brown on certain branches and dropping leaves. The limbs with green leaves are curling up a but and some have weird patters on them. I'm thinking this is either insect or or disease (doesn't look like oak wilt). Here are a few pics of the tree and leaves I pulled off. I live on the Bexar/Comal county line and the trees are about 14-16 inches in diameter.

My live oaks drop the twigs with leaves like that with some regularity.

However, the pics look like significant parts of your tree(s) are turning brown this time of year. I would contact an arborist in your area if those pics are what they look like. I had smaller patches of brown on all my trees one year, several years ago and was a little/lot concerned about oak wilt. It did not turn out that way though.

How old is the house? Any construction or irrigation trenching beneath canopy of the tree in last 3-5 years?

Could be Oak Wilt.

https://www.elitetreecare.com/library/tree-diseases/oak-wilt-disease/

https://texasoakwilt.org/

House is 20 years old, nothing has changed in last 5 years. Does anyone know an arborist to call in SA? I'd like to solve this issue before it potentially spreads to the rest of the property.

I can't figure out how only 2 trees out of nearly 1,000 live oak on my property are doing this and they're near my home. Something must have happened near the house as the the house is in the middle and whatever is ailing the trees had to skip 100's of trees in all directions.

Thanks for the help.

Oak Wilt most frequently spreads from tree to tree by root-to-root contact. Live Oaks regularly form functional root grafts with other Live Oaks. Red Oaks appear to form these grafts as well. Once the pathogen has entered one tree, it has the potential to move from tree to tree quite readily and efficiently. Root grafting is known to occur between Live Oaks and Red Oaks. This phenomenon is not common, but research indicates the potential exists.

Although infrequent, a second method of disease transmission is by overland spread. This occurs when fungal spore mats are produced on a dying Red Oak and visited by the suspected insect vector or transmitter, the sap-feeding nitidulid beetle. The beetle can carry the spores to a wound on a nearby tree but the spores can infect the tree only if the wound is fresh and created in the previous 24 to 48 hours. All oaks, including Live Oaks and species in the Red Oak family, can be infected by overland spread or root-to-root contact.

I had similar problems last year during pool and cabana construction. Had two arborists come out because we were worried about oak wilt, tree damage from construction or whatever was going to kill our trees. Both arborists agreed that green leaf/twig drops were somewhat normal, but ours was because of raccoons and squirrels. Also, the browning of some of our oak leaves was because of a window reflection after some smaller trees near the house were removed to make way for the pool and deck.

Something is eating the leaves..appears to be insect related.

According to attached article, your area is ground zero for oak wilt in the nation.


https://therivardreport.com/san-antonio-surrounding-cities-work-to-mitigate-oak-wilt-problem

Those leaves don't show Oak Wilt symptoms.

Are you putting out any "weed & feed" type products such as Bonus S? Atrazine can really mess up Live Oaks.

Squirrels are known to chew off the terminal tips of Oaks & Elms, but something else is definitely going on with your trees.

I'm not an arborist (though I intend to get licensed this fall) but I've been in the landscape business for 20 years. I lean towards your problem being bacterial leaf scorch or anthracnose fungus. Neither are good & if this is the case you may have to remove the trees. Get an arborist out asap before things get any worse.
I'd be interested in a follow up post to see what he says.

No weed and feed stuff, only a diesel/triclopyr mix around the house but not on the trees. I'm thinking mold or disease too. Oak wilt makes the leaves look different than mine. An arborist is coming out Friday morning. Hopefully not too late to save them. Would cutting off the affected branches slow down the spreading of this issue?

aggiejumper said:

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No weed and feed stuff, only a diesel/triclopyr mix around the house but not on the trees. I'm thinking mold or disease too. Oak wilt makes the leaves look different than mine. An arborist is coming out Friday morning. Hopefully not too late to save them. Would cutting off the affected branches slow down the spreading of this issue?

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Looks like diesel/triclopyr poisoning.

You may also want to investigate Hypoxylon Canker. It is spread by airborne spores.

Looks like you have an arborist lined up. I was going to suggest Bartlett Tree Experts.

That's who is coming out. Good to know they come recommended. I walked around my property and not a single other tree has any issues, I'm baffled and now it's up to the experts. I'll update y'all after the consultation.

Diesel/triclopyr around the house? What were you treating and was any of it applied within 30' of the Live Oak? When was it applied?
This is not Oak Wilt or squirrel damage. My vote is triclopyr. If you want to confirm there's a lab in Memphis I use when doing expert witness work...but they're not cheap. Test would cost $750-$1500. I don't think it'd be worth the money in this case. You know what was applied...now it's a matter of will the tree survive it or not.

I just the mix to kill brush and shrubbery around the property. I spray it on the stub/stump left to prevent any regrowth and in my driveway to kill the foliage growing through the decomposed granite. The property was not maintained for many years and had 4-6 feet of brush growth all around the house. I've used the mix for nearly 18 months all around the many oak groves and no other trees are showing any signs of sickness.

I guess the runoff and the heat and lack of rain stress in late May and all of June could have weakened the trees and allowed the poison to get to them.

That will work great for controlling brush but can also impact any adjacent trees. How close is this live oak to DG drive way?

I sprayed yaupon at our farm in Fayette county 3 weeks ago...two weeks after application they had very similar leaf burn. I'd keep that mix away from any oaks you don't want to damage.

Call and talk to Dr. Bill Lazby at Producers Coop in Bryan. He will help solve your problems and give advice on what to do. He is a specialist in ag. chem. and has done major research for all the big companies.

Aggiejumper.we have the exact same thing going on with some trees around our house at our ranch. We called the Agri - Life Extension Agent and he came out yesterday and ran some test on the trees. He said it is NOT a disease or oak wilt/decline. He said this is happening a lot in some areas of the hill country and that even though the trees look like they are dead or dying ( we have 5-6 with no leaves now at all for the last 6 weeks) they are in fact going into a mid summer dormancy due to the early spring/summer heat and drought. He showed us pictures of trees just like ours in 2011 in Kimble County that are fine now. He said he has been covered up with calls because of this in the hill country but said we should try and keep water on them and they would be fine next season. Told us to use soaker hoses and place them well outside the canopy. We had this same thing happen in 2011 on one of our other properties and the trees were fine the next year even though we thought they were done.

Wow-has it been that dry in hill county? We've had opposite issue with live oaks here in Houston. Have some dying from root rots with all the flooding.