I only use AS at the beginning of the season when I want to give a big quick boost of Nitrogen, after that I switch to a locally made blueberry / citrus 14-9-11 blend ($12 per 50 pound sack). I have used Hollytone in the past, but it just takes too much and it does too little, I currently have 2 mature 30+ year old rabbiteye blueberry bushes, as well as another 14 bushes that have been in the ground 3-4 years, some planted from 3 gallon containers, some bare root, most rabbit eye, though a couple of southern highbush (sweet crisp, indigo crisp, etc.). Native soil pH here is about 5.7, and so is the well water.