Perlite and vermiculite are both used in horticulture, but choosing between them should begin with the properties you need. They are not simply two brand names for the same material.
Vermiculite is commonly used for moisture retention and in seed-sowing applications. Perlite is often included to help keep a mix open and aerated. Grades and formulations vary, and the other ingredients influence the final result.
Follow the recipe or sowing instructions
If a reliable method specifies one material, do not substitute the other without understanding why it was chosen. A fine covering for a particular seed sowing has a different job from a structural ingredient throughout a large pot.
Use horticultural products and follow dust-handling advice. Keep packaging so you can identify the grade later. A note saying “white stuff” will not help reproduce a successful mix.
For a first plant, an appropriate prepared medium often removes the need to choose either separately. If you begin experimenting, use a small batch and compare its wetting and drying with your usual mix. The goal is a medium suited to the roots and your conditions, not a longer ingredients list that makes the care harder to interpret.
Further guidance & source notes
- University of Maryland Extension: Growing media for containers
- Royal Horticultural Society: Caring for soil
These are background resources, not an endorsement of this website. Regional instructions and the needs of your plant take priority.