Bonsai Tree Soil - All Purpose Blend Tinyroots All Purpose Bonsai soil is specially formulated as an all purpose potting medium for virtually any Bonsai tree. When it comes to choosing Bonsai soil, using right blend is important. That’s why we only carry soils blended exclusively by Tinyroots. The soil you use affects rooting, feeding, watering & transpiration; it’s where half your tree lives so this is our second biggest consideration in maintaining your Bonsai. Our soil is a mix of 100% organic double-sifted compost mulch, calcined clay, vermiculite & Frit. It contains over 28 vital trace elements & minerals that are essential for the health of your Bonsai. Bonsai Tree Soil - All Purpose Blend. Comes in 2 Quarts, 4 2.5 Gallons, & 5 Gallon Resealable Bag