10 Cups Large Particle Size Inorganic Soil Mix for Long Lasting Bonsai Soil - Pumice, Turface Lava. 33% - 1/2" - 1/4" Natural Cascade Mountain Volcanic Lava rock. Pleasing mix of red, grey, black and white. 33% - 3/8" - 1/4" Natural Cascade Mountain Volcanic Pumice. Pumice has many tiny gaps or air pockets that allow roots access to oxygen, nutrients and water. Pumice improves both water retention and drainage. 33% - Large Particle Size Turface . Turface is a high fired Calcined Clay. Particle size is 1/4 inch to 1/2 inch. 10+ cups volume. Neutral PH, doesn't rot, all natural, relatively light weight and porous. Our potting mix is hand packed and bagged with a reusable tie for easy storage after you have used part of the bag. If your potting mix dries before using, moisten it to keep dust from forming. Dust from any rock or potting soil product should not be inhaled and can be irritating for people with sensitive lungs. We are a commercial Wholesale / Retail Plant Nursery with over 17 years mixing specialty potting mixes. Check out our other listings of custom potting mixes to select the perfect mix for your bonsai or specialty plants. Use this soil mix as is, or add in your favorite locally available compost or organic matter to make the perfect soil. Scenic Hill Farm is a licensed Oregon nursery -- license # L0170090NG