Vermiculite for Mushroom Cultivation

Vermiculite is the cultivator’s secret weapon for locking in moisture while still letting mycelium breathe. Expanded from mica at high temperatures, this lightweight, inert mineral acts as a water reservoir, micro‑nutrient source, and aeration agent all at once… perfect for PF‑Tek cakes, CVG mixes, and casing layers!

Why Choose Vermiculite?

Our horticulture‑grade vermiculite is asbestos‑free, odourless, and OMRI‑listed for organic production. Its accordion‑like flakes trap water yet maintain air pockets, giving your substrate the humidity it needs without going anaerobic – one reason growers report faster colonisation and bigger flushes.

Versatile Across All Set‑ups

Whether you’re rolling PF cakes, blending a bulk substrate, or adding a cushioning casing layer, vermiculite adapts effortlessly. Fine grades cling to cakes during the “dunk‑and‑roll” while medium grades bulk out coco‑coir mixes – both reduce compaction and contamination risk.

Responsibly Sourced for Consistent Quality

We partner with long‑standing suppliers who meet strict horticultural specifications. Each batch is documented as asbestos‑free and packaged in sealed, dust‑reduced bags so it reaches you clean and ready to use.

What Is CVG Substrate?

CVG is a simple three‑ingredient bulk substrate made from Coco Coir, Vermiculite, and Gypsum. Home and commercial growers love it because it’s easy to prepare, stays fluffy, and resists contamination better than manure‑based mixes.

• Coco Coir (~50 %) – Hydrated coconut husk fibre that stores water and remains airy.
• Vermiculite (~40 %) – Gives extra moisture‑holding capacity and prevents compaction.
• Gypsum (~10 %) – Adds calcium and sulfur, buffers pH, and supports vigorous mycelial growth.

A handy starting ratio is 5 : 4 : 1 by volume (coir : verm : gypsum), hydrated to “field capacity” (a firm squeeze yields only few drop of water). Because CVG supplies structure and moisture but little nutrition, contamination risk stays low while your mycelium colonises rapidly.

Key Benefits of Vermiculite

• Locks in Moisture: Holds up to four times its weight in water, keeping humidity high throughout fruiting.
• Improves Aeration: Flake structure prevents substrate compaction for vigorous mycelial growth.
• Micro‑Nutrient Boost: Trace minerals can enhance mushroom nutrition and yield.
• Inert & pH‑Neutral: Won’t swing substrate pH or add contaminants.
• Heat‑Sterile by Nature: Expansion process gives vermiculite a naturally low microbial load.
• Reusable: Rinse, re‑pasteurise, and use again – great for the planet and your budget.

How to Use Vermiculite

1. For PF‑Tek Cakes
   • Mix 2 parts vermiculite : 1 part brown‑rice flour : 1 part water.
   • Sterilise in jars, inoculate, then dunk & roll fully colonised cakes in fresh, fine vermiculite before fruiting.
2. For CVG Substrate
   • Combine coco coir, vermiculite, and gypsum (about 5 : 4 : 1 by volume), hydrate to field capacity, then pasteurise or sterilise.
3. As a Casing Layer
   • Sterilise or pasteurise coarse vermiculite, allow to cool, then apply a 0.5–1 cm layer over colonised bulk substrate to maintain surface moisture.

Tips for Success

• Field‑Capacity Test: Squeeze a fistful – only a drop or two of water should escape.
• Keep Airflow Up: Pair vermiculite with ample FAE (fresh‑air exchange) to prevent CO₂ build‑up.
• Mask Up: Avoid inhaling dust when handling dry vermiculite (wear an FFP2 or better respirator).