Play nice guys.
I fertilize soon after they break dormancy and are putting on new growth at a steady pace, then again around now, actually it would be better a week or so earlier than now. What I have been using is a natural blend fruit fertilizer, forgot where I bought it. It was cheap. Some us Osmocote slow release which allows a more constant feed, but it's a little expensive when you've got alot of trees. And still others use a manure of some sort. What you are doing seems fine with one possible exception. Be careful about feeding young trees newly potted in Miracle Grow. MG usually comes with a slow release fertilizer already in the mix. Young trees have sensitive roots that are subject to burning, adding more fertilizer could be a recipe for disaster. Young trees need very little fertilize.