Edro, is this tree a new transplant and do you have others that look ok? Tell us more about the situation it is in.

ITS SEPTEMBER....

the leaves will fall off soon..

quit 'giving' it stuff ... its stressed... NOT HUNGRY ...

dig a hole .. and YOU find out if you are under or over watering... how can we possibly know ...

can you see the root flare???

ken

Thanks for the input. The tree was transplanted almost a year ago. I have another red oak nearby but no issues with that one. This is the 3rd tree I have planted in this same spot over the past 8 years though. It might be something in the soil, but this one seemed to be doing fine over the past year and then suddenly got worse in the last couple of weeks when we started hitting 100+ degree days. I cannot see the root flare.

Several possibilities edro. First of all only about 50% of all trees transplant well because of the tremendous shock to the loss of roots, add the stress of hot weather and that could be your problem. Also was it transplanted from a field (better) or from a nursery (worse - they often let their trees get pot-bound and then the roots start choking each other from twisted girdling by around the second year. Also could have been planted too deep, common cause of root rot with no oxygen to the root flare. Best, Bob :-)

Thanks, Bob. It was transplanted from a nursery. It just concerns me that the other Red Oaks nearby are doing just fine. How can I tell if it is diseased instead of just stressed?

Edro - You asked how you can tell if it's distressed or diseased. Diseased is just a later stage of distressed. So you want to try to eliminate the stresses (there's always more than one before you start seeing symptoms of distress).
1) Is the distressed foliage localized in parts of the tree (indicates a living source like insects, fungus or bacteria) or uniformly throughout the tree (indicating a non-live source like injury, water availability, girdling roots, etc.)
2) Another way to tell is to take some branch and root samples to your local County Extension for lab testing or ask them if there is a university plant pathology lab where you can get them tested, usually about $40.
3) Another way is to have a tree service company that has an air spade to safely blow the dirt out (or a vacuum that sucks the dirt out) so you can see the shape of the roots. Ideally they would be in a star pattern radiating out from the trunk, unimpeded. If they are twisted, diving, girdling around the trunk from being root pot-bound at the original nursery or farm, then you know it's the roots causing lack of water and nutrients getting to the tree and you might as well remove it. This is what I'm suspecting.
4) You could get a soil test done at a local private or university lab to see if there are major nutrients deficient in the soil, but I sorta doubt this with the other trees doing well.

you had 99% of its roots hacked off.. and you are fixated on disease...

WHY?????

its stressed... to the max..

and it will be .. until it regrows the ENTIRE LOST ROOT MASS ...

and forget about comparing two trees next to each other..

it is obvious,... that one is less stressed.. and since we can not see into the ground.. we can only speculate.. that perhaps it only had 90% of its root mass cut off.. and that is the difference right there...

and NEVER... spray a stressed tree.. the leaves are already damaged.. so what do you want to do.. smother them further in chemicals..

your are way out in left field.. and the baseball.. is near the water feature in right field..... go get the ball ....

PERFECT your water.. dig that hole.. find out... mulch properly..

and retain your receipt...

frankly. a little leaf damage in september.. means nothing... its fall ... and this tree isnt evergreen.. unless its some magical texas red oak??? .. so all the leaves will be falling off.. pretty soon ...

ken

Where do you live and where did you get the tree from?

In case, that tree does not survive, I may be able to direct you to a nursery that specialized in superior root system growth for fast establishment in the ground.

Leaves will react as shown in your pic with they are water stressed and this is exaggerated when the temps get in the triple digit range. Usually, when proper watering in restored to the tree (along with a good mulching, never underestimate the power of an adequate mulch mound) the process should slow down and hopefully come to a halt. The tree knows it doesn't have enough water to keep the normal processes going in the leaves and it is slowly and systematically closing off those pathways to prevent further water loss. This presents on the leaf as a gradual browning starting from the leaf tips that continues to the leaf petiole.

New transplants are the most susceptible to this phenomenon. 1 year in the ground in the Texas heat and lack of abundant rain is definitely enough to cause these symptoms. In a dry climate, you may have to provide supplemental water for 2-3 years after transplant and much longer in times of severe or worse drought.

I have seen this phenomenon happen to numerous trees locally in the summer of '11 and '12.

I really appreciate all of the feedback. This morning I checked on the tree and saw this black sap coming out of the trunk. Any ideas? Tree borers maybe?

That appears to be the work of an oak borer. In healthy trees, they're nothing to sweat unless the tree is under siege from *lots* of them.

Is this the same tree as you're concerned as expressed in the opening of this post, or is this a different problem/tree? This tree looks rather large for a transplant, but if it is, judging from the amount of moisture flowing from that wound, I'd say that it's getting enough water.

Some time ago,a Red Oak of mine had this happen just as shown in your photo, so I took a flat toothpick and loaded it up with sevin dust and slapped it into the wound. I did this many times. It might have killed the borer, or not, but it made me *feel* good! Haha!

Brad N.IL/Z5