Vermiculite 4 Cubic Foot Bag A-2 Medium (OMRI ORGANIC)
Vermiculite 4 Cubic Foot Bag A-2 Medium (OMRI ORGANIC) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Description
Description
Palmetto Organic Professional Grade Vermiculite in a 4 cubic foot bag — about 30 gallons of A-2 medium vermiculite, OMRI Listed for organic use. It holds water evenly, making it a go-to for mushroom substrate hydration, casing layers and PF Tek.
The A-2 medium grade sits between fine and coarse, a better fit for mushroom work than the coarse vermiculite sold at most big-box stores. It’s asbestos-free.
- 4 cu ftBag size
- ~30 galVolume
- A-2Medium grade
- OMRIOrganic listed
- PalmettoProfessional grade
Why growers use this vermiculite
- Medium grade – A-2 medium coarseness is well suited to mushroom cultivation.
- Even moisture – Absorbs water evenly to keep substrate and casing hydrated.
- OMRI Listed – Certified for organic use.
- Asbestos-free – Professional grade vermiculite from Palmetto Organic.
- Bulk value – A 4 cubic foot bag covers many jars, bags and tubs.
What you can use it for
- PF Tek and BRF substrate — learn about PF Tek
- Dunk and roll for PF cakes
- Mixing into bulk substrate, such as with coco coir
- Casing layers on bulk monotubs — casing guide
- General moisture retention
How to use it
- Measure. Scoop out what you need for your recipe; reseal the bag to keep it clean and dry.
- Hydrate. Add water gradually and mix until it’s evenly moist, not dripping.
- Mix or layer. Combine it into your substrate, or spread it as a casing layer over colonized bulk.
- Prepare as your method requires. Sterilize or pasteurize as your recipe calls for before use.
New to substrates? Read what mushroom substrates are and why they matter.
Specifications
| Specification | Detail |
|---|---|
| Brand | Palmetto Organic Professional Grade |
| Bag size | 4 cubic feet (about 30 gallons) |
| Grade | A-2 medium |
| Certification | OMRI Listed |
| Asbestos | Asbestos-free |
| Uses | PF Tek, dunk and roll, bulk substrate, casing, moisture retention |
Need less?Try a 1 quart bag of vermiculite, or pair this bag with a 4 cu ft bag of coarse perlite for your fruiting chambers.
FAQ
What grade is this vermiculite?
A-2 medium — between fine and coarse, a good fit for mushroom cultivation.
How much is in the bag?
4 cubic feet, about 30 gallons.
Is it organic?
Yes. It’s OMRI Listed for organic use.
Is it asbestos-free?
Yes.
What is it used for in mushroom growing?
PF Tek and BRF jars, dunk and roll for PF cakes, bulk substrate mixes, casing layers and general moisture retention.

