Question
What would cause a willow tree that is about 15 ft to suddenly have leaves through the middle of the tree turn yellow through summer and one branch have green leaves?  The top of the tree has no leaves.  Can you tell me what might be wrong?

Answer
Silver:
Be sure that the tree is getting adequate water- these trees usually like plenty of water, or leaves yellow then drop off.  Also examine trunk for any evidence of bark damage- this may indicate internal decay.  Good deep, but infrequent irrigations may be needed, even if it is in your turf.

Steve