Leaf drop is normal for a live oak in spring, but yellowing and browning now is not. The tree appears to be in some type of stress. Drought, soggy soil conditions, damage from a weed killer (such as might be in a weed and feed product), or just stress of a recent (this past winter or spring) transplant are all possibilities. If the plant has been in less than a year, try giving it a little fertilizer and keep the soil moist. If it was put in a clay soil the planting hole could be confining the roots if the hole was not dug properly and the original soil from the site filled in well around the roots to remove air pockets. There is little to do after planting to correct a problem with a bad planting hole. The following web site shows the proper way to plant a tree for your future reference just in case this was the problem:
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips