Q. What's wrong with my Yellowwood? Cladrastis lutea
Your yellowwood should not have brown leaves. The past winter was hard on a lot of plants with a wetter than usual spring followed by a extended dry period. If it was weak this year the leaves might turn yellow earlier than usual but not brown. In dry conditions trees should be watered deeply and slowly to prevent runoff followed by several days until repeating the process to prevent drowning the roots which require oxygen as well as moisture. Sometimes trees are watered briefly and too often creating weak, shallow roots. Try pruning a few small branches off to see if there is any green beneath the bark. If the branches snap and appear brown and dry inside you will need to replace the tree.