Question
We have a large willow that has started losing leaves at a daily rate. they turn yellow and on a hot day seem to rain down all day!Some have a brown dot,but not all.I don't see aphids or any bugs. I do notice another willow about 50 yards with the last 3 feet of its branches dead.It seems to be having problems,but does not defoliate like ours. thanks for any advice  warm regards,kevin

Answer
Kevin:
Check for any damage to the bark near the base of the tree. Check also for any apparent root injury from digging/lawnmowers etc.  If these items are OK, then I would lean toward a moisture fluctuation in the soil.  Many willows like soil a bit on the moist side.  If the soil dries, they starting yellowing then dropping leaves.

Regards
Steve