Greenhouses

Vermiculite vs perlite: What’s the difference?

Choosing the right soil amendment is crucial for a thriving garden, Vermiculite and Perlite stand out as popular options.

Let’s understand each key difference and when to use them.

Vermiculite – the moisture retainer

Derived from micaceous minerals, vermiculite is prized for its water-retaining abilities. It keeps the soil consistently moist, ideal for moisture-loving plants. This makes it a fantastic choice for seed starting and germination.

Perlite – the aerator

In contrast, perlite is a volcanic glass that undergoes heat expansion, creating a lightweight, porous structure. Its primary role is aeration – enhancing soil drainage and preventing compaction. This makes perlite excellent for succulents and plants that crave well-draining conditions.

Perlite 100 litre bagWhat is the difference between Vermiculite and Perlite?

Origins

  • Vermiculite: Mined from micaceous minerals, usually found in deposits across the globe.
  • Perlite: Formed from volcanic glass that expands due to heat, creating a lightweight and porous material.

Texture and appearance

  • Vermiculite: Soft, spongy texture that expands when heated, resembling mica flakes.
  • Perlite: Lightweight and airy, with a white, granular appearance.

Water retention

  • Vermiculite: Excellent water retention, making it ideal for moisture-loving plants and seed starting.
  • Perlite: Provides aeration and drainage, preventing soil compaction. It doesn’t retain water, making it suitable for plants that prefer drier conditions.

Aeration and drainage

  • Vermiculite: Aids in aeration but is more focused on water retention.
  • Perlite: Promotes excellent drainage and aeration, preventing root rot and enhancing overall soil structure.

pH level

  • Vermiculite: Slightly alkaline, which can impact the pH of the soil.
  • Perlite: pH neutral, ensuring it doesn’t significantly influence the soil’s acidity or alkalinity.

Best Suited for

  • Vermiculite: Ideal for plants that require consistent moisture and for seed starting.
  • Perlite: Suitable for plants that need well-draining soil, including succulents and those susceptible to root rot.

Weight

Vermiculite: Relatively heavier compared to perlite.

Perlite: Lightweight, contributing to the overall lightness of the growing medium.

Should I choose Vermiculite or Perlite?

By now you should have a better understanding of both.

Consider your plant’s water needs. If moisture retention is key, opt for vermiculite. For plants that demand well-draining soil, perlite is the go-to choice.