Question
I have a White Oak about 5 feet in diameter (15 feet around)that has over the last 8 weeks had about 85% of its leaves turn brown.  The tree is in Northern VA and we have been dry.  The tree was all green in early May. Although there is no physical evidence, could lightning have affected this tree?  It must be 200 years old and sits between two homes with a driveway close by.  Could fertilizer (weed control) have such an immediate impact on a large tree (60feet tall)?  There is another oak about the same age about 150' away that looks healthy.  This tree had survived between these houses since 1955.  There has been no regrading within several hundred feet of the tree.  Any thoughts.

Answer
This sounds like it could be a combination of several things. IF a lawn fertilizer with a herbicide was used around the tree this can cause damage and die back of the foliage. If it were lightning there should be a scar on the trunk unless the lightning hit the ground near the tree and then you should see where the strike hit the ground. I would recommend that you call the Va. Department of Forestry (state agency) and ask one of their Foresters to come take a look on the ground. He should be able to ID the problem since he can look at the tree and the surroundings. Here is the web link to their county contact page.

http://www.dof.virginia.gov/info/my-county.shtml