Question
We have an oak tree that seems to be dying.  It's acorns have not developed and the leaves appear to be turning brown on the outside edges but green (still) in the middle.  We had another oak tree, closely adjacent, that started to bloom this spring, but then stopped. I was reading a previous answer where you told that if you put asphalt around an oak tree it will die.  We had the driveway next to the oak trees paved last summer, but they are not completely surrounded by the asphalt.  The trees are next to the asphalt.  The other sides (3) are still open dirt with field flowers or wild flowers around them.  Could the asphalt be the culprit in this case too or do we have a bug or disease?  We are in western South Dakota.

Answer
Any distrubance of the roots espectially near the tree trunk can cause die back of the foliage. The paving side should coorespond to the leaf die back --same side of the tree. You can dmage up to 1/3 of the trees root system without sevirerly dmaging the tree. IF you broke up the soil for the flower beds this will also damage the roots. The trees root system is in the first 12-24 inches of the soil so any digging in this area could cause die back. The good news is the damage has been done and will not increase and  the tree will recover and you should see an inprovemnt next year when it leafs out.

This Fall after the leaves have fallen I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. If you apply the fertilize just before a rain storm you will not need to water. This will increase the root growth and increase the overall health of the tree. Next spring I would fertilize again after the tree leafs out fully.