I have 2 ash trees (White I believe) planted in my parkway 10 years ago. The trees appear healthy with vigorous growth each year. During the last 2 years I have noted limbs that crack near the trunk after windy days or after dewy mornings. Some of the limbs are 2 inches in diameter and some are larger about 4 inches. It seems that the foilage is so heavy that the limbs crack. Is this normal or does this indicate a problem with the tree?

Mike, If they are cracking it may indicate a poor branch angle. In other words the branch is held at too tight an angle to the trunk so included bark forms at the attachment. Makes for a poorly attached branch. I would suggest having a certified arborist come out and take a look at it or you may decide to go ahead and remove the branches if it makes sense for the outline of the tree.