Enhance Your Soil! these expandable “bricks” make those heavy bags of peat moss a thing of the past. This soil enhancer loosens hard, clay soil, which increases the transplant success of most fruit trees. It also holds moisture longer and adds water-retaining fibers to sandy soil. This medium stays porous and resists compacting, which promotes strong root development. Its fluffy texture will not crust when dry, either. Gro-Brick has a neutral pH of 5.7-6.3 and is free of weed seeds and diseases. Made of 100% natural, biodegradable coconut fibers. Mix with water and it will grow to 6-9 times its original volume. Large brick expands to 80 quarts.