Do you fertilize your lawn heavily w/ nitrogen around/near the tree? 3 numbers in a fertilizer, such 10-5-3. First is nitrogen for leaf growth; second is phosphorous for flowers/roots; third is potash for stem strength/disease resistance.
Too much lawn fertilizer leeching into tree roots will stymie flower buds and promote leaf growth.
Use your fingernail and lightly scratch stems near buds, ¼" or so, to see if the branches have green wood underneath the bark.
Green = good; brown = bad.
