Perlite vs. Vermiculite
The Battle of the Soil Amendments. One holds water, one drains it. Which one does your garden need?
The Main Difference
Vermiculite
The Sponge
Expands to absorb water and nutrients. Best for plants that need consistent moisture.
Perlite
The Drain
Creates air pockets and sheds water. Best for plants that need fast drainage and dry soil.
Is Perlite the Same as Vermiculite?
No. While both are mined minerals that are expanded by extreme heat, they serve opposite functions. Vermiculite is a silicate that holds water like a sponge. Perlite is a volcanic glass that is hard and porous, designed to aerate soil and drain water. Using the wrong one can harm your plants (e.g., using vermiculite for a cactus could cause root rot).
Comparison Table
| Feature | Vermiculite | Perlite |
|---|---|---|
| Water Retention | High (Absorbs 3-4x weight) | Low (Surface only) |
| Aeration | Moderate | Excellent |
| pH | Neutral to Slightly Alkaline | Neutral |
| Weight | Light | Ultra-Light (Floats) |
| Best For | Seed Starting, Tropicals | Succulents, Cacti, Propagation |
Which One Should You Choose?
Starting Seeds
Seeds need constant moisture to germinate.
Winner: VermiculiteSucculents & Cacti
These plants hate "wet feet" and need fast drying soil.
Winner: PerliteVegetable Garden
Most veggies need a balance of moisture and air.
Winner: Mix BothPropagating Cuttings
Needs air for roots but moisture to stay alive.
Winner: Perlite (or Mix)Clay Soil Amendment
Heavy soil needs physical aeration to break it up.
Winner: PerliteHydroponics
Both work, but perlite is more common for its drainage.
Winner: PerliteCan I Mix Them?
Yes! In fact, the "Holy Trinity" of potting mix is often:
The Perfect Mix
1 Part Peat Moss (or Coco Coir)
1 Part Perlite
1 Part Vermiculite
This creates a soil structure that holds moisture (thanks to vermiculite) but drains excess water freely (thanks to perlite), giving your plants the best of both worlds.