Many home gardeners would love to grow their own blueberries, but hesitate to try because of the plant’s special needs. This product is really not a fertilizer, but an earth-friendly sulfur, which by lowering the soil pH, allows the blueberry plant to draw up the nutrients it needs. Simply scattering a handful around every plant each spring before topping up with a fresh coat of mulch goes a long way toward keeping your blueberry plants healthy and green. Blueberry Booster is 80% Bio-Sol90 (Elemental Sulfur) and 20% Earth Boost (Dry Humic Acid).