I personally think that you are feeding it way too much. Mine in Florida grew thick branches and I only fed about once every six weeks. Plus there they shed their leaves and went dormant for about four months.
The leaves started to yellow and drop from October 1st on. So without active growth there is really no need to feed them. They would come out of dormancy starting about February 1st depending upon temperature. If it was a cooler winter, maybe they started mid February, late January during a warmer winter.
But once new leaves were an inch or so long, I fed them. I used an even blend of 20-20-20 at a half teaspoon per gallon.