if you are giving it a lot of nitrogen it may be producing vegetative growth instead of flowers. I would lay off the miracle grow altogether. Next February after your winter pruning give it a good top dressing of a high potash fertilizer - sulphate of potash or even wood ash, as long as there are no other ashes mixed with it. This will encourage the formation of flower buds. Around late March you can then mulch it with well rotted manure or compost. This is all I have ever done to mine and I have always had bumper crops.