Pumice is basically whipped volcanic glass that is made up of tiny air bubbles. This means that pumice is a lightweight volcanic rock that makes it perfect for use as a soil amendment.
The airy rock is ideal for use with cacti and succulents as well as other plants that require excellent drainage and air circulation. Plus, the porosity of pumice allows microbial life to thrive while maintaining soil structure better than perlite. Planting with pumice also has the advantage of a neutral pH along with a variety of trace materials.
There are many advantages to growing plants in pumice. It reduces water runoff and fertilization by increasing soil absorption in sandy soils. It also absorbs excess moisture so roots don’t rot. Additionally, pumice improves aeration and stimulates the growth of mycorrhizae.