Expanded shale is a gaining in popularity as a soil amendment in gardens. It is made by exposing shale pellets to very high temperatures causing the pellets to expand and enabling them to support roots and hold moisture. Expanded shale is great for clay soils, is long lasting, is organic, improves drainage and aeration, and is non-toxic. It is light weight and easy to handle and is economical. Expanded shale is great for soils, but it doesn’t replace the need to add compost or other organic matter.
Growing Home - Expanded Shale
