unless you have severe clay.. why is the tree staked like that??? a bit of overkill to my mind... is there any suggestion that it is not secure in the ground??? probably winter damage.. due to planting at the wrong time of year.. leading to severe lack of water in fall and winter ... complicated by winter sun thawing the tree bark .. ignore it.. and see what happens after the next 2 years ... if you can get the dead bark flap off without doing further damage.. that will reduce a place for bugs or moisture to accumulate ... leaf damage is irrelevant ... get rid of the stakes.. maybe.. ONLY ONE .. upwind of the prevailing winds .... kill the grass.. ID the root flare ... and insure it is not buried.. and add a 6 foot circle of mulch ... dig a small hole and find out if it is moist thru out the root mass ... and do not let it dry out again.. w/o drowning it.. for the next 2 years ... good luck ken

Would a planting issue have happened so late? Like I said, the tree was planted at just an inch or so around. The dead area is much larger than the tree was when it was planted. I was thinking the shed wouldn't have cut any roots, because it is one of those prefab plastic things. It shouldn't have much soil compaction either, as I built a 2x6 raised floor (or maybe that's actually more soil compaction, but just where the 2x6's touch the ground). But it is covering an 8x10 area, so it may work like burying the roots, I suppose. Regardless, if the shed is the problem, the root is already dead, right? So moving the shed at this point would be pointless? My wife says the color isn't as green as other live oaks we have, but other than that it doesn't really have any issues with its leaves. I don't know what oak wilt looks like, but I have another oak that seems to have a general dying of leaves. I'll probably post pictures of it in another thread eventually.

Two possibilities. Get some "deer corn" from a feed store and place it where they will do no damage. My grand daughters have a tree house and I built bird and squirrel feeders on nearby trees so they could feel like they were out of the city. They also put out yarn and cloth strips for the birds to put into their nests but I did see squirels carrying this also. If this fails then go to a feed store or Home depot in the gardening section with the chemicals you will find large green or yellow cylinders about 1 inch in diameter and 1.5 inches long with a hole through the middle just nail these about 4 ft off the ground and replace when gone until the squirrel population is controlled. Last year I had a bumper crop I counted 8 to 12 in my trees several times and 5 was the normal number. They dug up everything within 3 ft of the trunks. After a week of the spools I was down to 3 squirrels and I could tolerate the small amount of damage that they did. Put the spools where any dogs will not be able to get to any remains, at some point small pieces will fall to the ground but these are usually eaten by the squirrels. Bill

Hey look like aphids. A closer pic would help better. I would spray with a neem solution.