Mineral growing medium for potted plants, perennials and woody plants in outdoor containersVulkastrat, also known as volcanic substrate, is a special type of growing medium made from volcanic rock.Vulkastrat® 2/8 is a pure mineral substrate made from pumice, zeolite and lava in grain fractions of 2-8 mm. Zeolites are natural ion exchangers, i.e. minerals that can absorb and release substances. Zeolites therefore make the use of organic substances superfluous. Due to their high exchange capacity, zeolites fulfill a similar function to humus and clay in natural soils. In addition to good nutrient storage, the high-quality zeolites mixed in ensure a stable pH value and odorless water.Vulkastrat has several advantages over other types of substrates: ...