PRO BONSAI SOIL 4 qt (1 gallon) TRIPLE SCREENED. 100% aggregate soil. Some growers prefer mulch free soils for better aeration/water retention properties and fibrous root development. Provides better nutrient absorption and growth. Make sure your are on a Regular Fertilizing routine, because there are no organic mater contained in the soil. Note, some settling does and will occur, even when screened.