I have what looks like some kind of fungus that killed a post oak in my backyard. Is this oak wilt, and will it spread to my other trees?

Thanks.

Need pics of the dropped leaves to really be able to tell, but even then it would only be an educated guess. Post Oaks are pretty resistant to Oak Wilt, so keep that in mind.......

That's just a straight up dead post oak IMO. They usually grow in drought-prone soils and/or heavy red clays and they really get stressed when you're in prolonged droughts like we are now. When they're fighting for their life any little problem like insects or damage will knock them out, even the large ones.

You will get the technical answer in a minute...but I had the same thing. Its a type of fungus that is present in most trees but doesnt kill the tree until it is stressed enough to allow the fungus to take over.

I have lost nearly a dozen 30-40 inch diameter Post Oaks this spring and summer. I hate those damn trees, they are so fragile when it come to disease.

My guess is hypoxylon canker. I've lost almost 40 in the last couple of years. Starts with stress to the tree.

http://easttexasgardening.tamu.edu/homegardens/hypoxylon.html

Drought stress will open a tree up to many fungal diseases and insect infestations. Post Oaks are not susceptible to Oak wilt, though.

I have a post oak in my front pasture that turned brown in July of 2009 and went dormant. It had been hit by lightning previously. It came back the next year, so check to see if the branches are still green (scratch them with your thumbnail). By the looks of that bark falling off though, it doesn't look encouraging.

Post oaks are a species of the white oak group, and are less susceptible to oak wilt, but blackjack oaks are in the black/red oak group, and it will kill the hell out of them.

This is a different fungus, and with the drought, it is hurting the hell out of post oaks.

I've seen huge wooded lots down here in the Houston area where every water oak appears to be dead or dying. They're trees that thrive in moist conditions, but this drought is decimating them.

I've lost several white oaks on my land to some unknown cause. Ike beat them up some, and something else finished them off.

[This message has been edited by MouthBQ98 (edited 8/29/2011 1:43p).]

bacterial infection, phospherous infusion to save the rest.

good news about all the hot weather is that the oak wilt fungus is killed when the temperature is over 95'F

quote:

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Post oaks are a species of the white oak group, and are less susceptible to oak wilt, but blackjack oaks are in the black/red oak group, and it will kill the hell out of them.

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We had this conversation a week or so ago, right? You get a blue star & 5 innernet points for remembering!

I’ll take a crack at this one but not seeing the tree makes this just another guess.

Post Oaks cannot regenerate their roots. This is why you cannot purchase them from a nursery. Can’t grow them and then transplant. Roughly 90% of the roots are within one foot of the surface.

Have you disturbed the roots in any way? Installed an irrigation system, landscaping, or maybe removed youpon or planted something nearby.

Also building any fencing will break the root structure as well as operating heavy machinery around the tree such as bulldozers or bobcats.

Post Oaks hate people. They will die if you mess with them or try to make them into a part of your landscaping scheme.

Also make sure your irrigation system or septic is not spraying on the tree, this causes sun scald that will cause the bark to fall off.

Then again… they just die for no reason.

Oak Wilt fungus does not die over 95 degrees. The nitidulid (sap) beetles that transmit the fungal spores stop being active at that temperature.

only soil disturbance was about 10 feet to the left, where we dug some post holes for a deck last summer.