Perlite is an amorphous volcanic glass that has a relatively high water content, usually formed by the hydration of obsidian. You can still use a conventional potting soil containing perlite, however, you may have to control watering more frequently than those composed of vermiculite. Because of its thermal and mechanical stability, non-toxicity, and high resistance to microbial attack and organic solvents, perlite is widely used in biotechnological applications.
It is an industrial mineral and a useful commercial product because of its low density after processing. The result is a highly expanded mineral popcorn, white in colour due to light reflecting off small bubbles on the surface of its particles. A premium mix of one part loam, one part peat moss and one part perlite is optimal for container growing, as it allows the pot to contain sufficient water and oxygen. Perlite is a form of volcanic glass (SiO) that is mined all over the world.
What is perlite used for?
It is also popular as a filtering agent, often used to filter spent grain or other solids from beer or in the biochemical industry. It is excellent for creating free-draining compost for plants that need good drainage, such as cacti and succulents. Perlite Uses Perlite is used in soil mixes (including soilless media) to improve aeration and modify the substructure of the soil, keeping it loose, well-draining and defying compaction. But that's what I like about perlite, it can be selected as a soil mix, soilless growing medium or fertilizer.
Perlite is a naturally occurring mineral that is added to garden soil to improve aeration, water retention and drainage. However, if you use a commercial potting soil that contains perlite, the chances of this happening are very slim. Perlite is commonly used in potting soil and soilless mixes (especially for indoor planting) to keep the soil structure loose and well-drained without the risk of compaction over time.
Why do gardeners use perlite?
Both perlite and vermiculite are used in the garden to improve drainage, prevent soil compaction and increase moisture retention. I created Epic Gardening to help teach 10,000,000 people how to grow anything, no matter where in the world they live. Many plants thrive in high moisture conditions, so if that is a concern in your garden, perlite is right for you. With a degree in agronomy and over a decade of gardening experience, Amanda combines her knowledge of plants and her writing skills to share what she knows and loves.
They are used in both propagating new plants and starting seeds and growing for indoors, outdoors and composting. Get an annual subscription and choose a gardening package when you subscribe to BBC Gardeners' World magazine. In addition, there are misconceptions about replacement products such as vermiculite or diatomaceous earth. Read on to learn more about these two all-natural soil amendments that gardeners use to change the water and nutrient retention levels in their garden soil.