AUSPERL Horticultural Vermiculite
AUSPERL Horticultural Vermiculite is what commercial nurseries use for seed raising and propagation - an inorganic growing medium that holds water while still draining freely.
Potting mix that's either soggy or bone dry?
Standard potting mix is hard to get right. Too much peat and it stays waterlogged. Too much drainage and it dries out in a day. Seeds rot or don't germinate. Cuttings fail.
Holds water, but still drains
Vermiculite is made from heated mica that expands into tiny, sponge-like flakes. Those flakes trap air and water in equal measure - so your mix drains freely while still holding moisture where roots can access it.
Seeds get the damp-but-not-soggy environment they need to germinate. Cuttings root without rotting. And because it's sterile, there's no disease, weeds, or soil-borne insects to deal with.
It's also lightweight. A bag of potting mix made with vermiculite is noticeably easier to lift than straight peat or compost.
Four grades available to suit different jobs:
- Grade 1 (Extra Fine, 0-1mm): Seed raising, fine propagation
- Grade 2 (Fine, 2-4mm): General propagation, seedling mixes
- Grade 3 (Medium, 3-6mm): Potting mixes, soil improvement
- Grade 4 (Coarse, 5-8mm): Drainage layer, chunky mixes
How to Use It
| Use | Mix Ratio | Notes |
|---|---|---|
| Seed raising | Pure vermiculite or 50/50 with peat | Provides ideal moisture for germination |
| Cuttings | 50/50 with peat or perlite | Good aeration, prevents rot |
| Potting mix | Add 10-30% to standard mix | Improves water retention and aeration |
| Soil improvement | Work into garden beds | Helps heavy soils drain, sandy soils hold water |
Good to Know
Vermiculite is slightly alkaline, so if you're mixing it with peat (which is acidic), the two balance each other out. Popular with orchid growers and propagators who need precise control over moisture levels.
Once it dries out completely, vermiculite can be tricky to re-wet - so water from below or use a wetting agent if you're working with pure vermiculite in trays or pots.
At a Glance
| Type | Expanded mica (inorganic, sterile) |
| pH | Slightly alkaline (can be neutralized with peat) |
| Properties | High water retention, excellent aeration, insulating |
| Grades available | 1 (Extra Fine), 2 (Fine), 3 (Medium), 4 (Coarse) |
| Common uses | Seed raising, propagation, potting mixes, soil improvement |
| Made by | AUSPERL |
