2024-07-04
How to Use Soil Amendments - Vermiculite
Have you ever noticed how some potting mixes sparkle in the sun? That’s because they contain vermiculite, a soil amendment that helps with water retention, aeration and nutrient exchange. Vermiculite is a phyllosilicate mineral that is mined from rocks formed 1.5 to 3 billion years ago. Crude untreated vermiculite is used in a variety of industrial materials. The garden variety of vermiculite is called “exfoliated” vermiculite, which has been treated with extreme heat and pressure to force it to expand. This process creates a porous surface that is great for retaining moisture and nutrients. In the past, some vermiculites contained asbestos. However, those contaminated mines were shut down and modern vermiculite is rigorously tested to make sure it is free of this carcinogen.Vermiculite is a non-toxic mineral that will not deteriorate in your soil mix, so its effects last for a long time. Since it does not break down, it is not useful as a source of nutrients. Instead, it is a structural helper to promote improved soil. Its unique shape traps water and nutrients, which can be extracted by plant roots as needed. This means you need to water less often in high temperatures than you would with soil that does not contain vermiculite. This growing medium can help retain water and nutrients. Mixing vermiculite into your growing medium can help promote optimal root growth.