rockm

For what it's worth, "feeding" or fertlizing a leafless tree will not promote leafing. Trees produce their own food WHEN IN LEAF. Fertilizer provides only the building blocks that the tree uses to make its own food. Providing those blocks with no leaves is useless, since the tree cannot use them.

Your tree lost its leaves not because it entered dormancy, but because it was shocked by the frost. Dormancy is not temperature induced and therefore simple exposure to cold temperatures for a night or two won't induce a dormancy.

You tree will most likely recover and begin pushing new growth. Fertlize once than new growth has opened for the best results.

Skip the Superthrive. It is useless, expensive and basically a scam.