Happy Frog Japanese Maple Fertilizer (4 - 3 - 4) could be used if it contains the nutrients that are needed by the tree and a nutrient issue is the reason for the tree not blooming as expected.  We apologize but cannot confirm it would work nor make a recommendation without knowing the issue, and we are not able to identify diseases.  We would recommend contacting a local arborist or master gardener at your local cooperative extension office or local nursery to see if they are able to assist.  They would be more familiar with any issues on the trees in your area and what the cause would be. You can find your Master Gardener here.