if yer growing out side yer gonna get insects, no matter what yer soil, I use one bag of potting soil no name brand, a wheel barrow load of pig and horse shit and worm castings mixed with compost all into 3 foot deep holes includeing a 3 foot diameter, voila watch em grow with out chemicle ferts, thats why i do anyways, mites and such i use a spray made from Pyrethrins that takes care of most insects.