Vermiculite Options

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By ion ewe (Ion) on Thursday, September 20, 2001 - 12:44 am:

I have recently been outraged at the unavailability of good verm. I have called many a company and sent a few letters. Here is what I've gathered:

Vermiculite is mined from the earth in many places. It is then processed with heat and pressure to make it fluff up. The chunks mined determine the size of the final product. There are five grades of vermiculite in the industry. They are just called #1, #2, #3, etc. The higher the number, the larger the grain size (I think, but can't remember exactly.) The smallest is just like dust or sand. The largest is about 1/4 to 1/2 inch chunks. The ideal for our purposes is about the size of a pencil eraser at it's largest. #4 I believe.

Now the bad news... It seems that Schultz carries the verm produced by the biggest firm in the US. This firm, however, has been under federal pressure as of late. A few years ago, there was a mine in Georgia (I think, again) that they got most of their verm from. This mine happened to be next to a large deposit of asbestos. They realized this, and shut the mine down. But the damage had already been done. Our friends in the media felt the need to spew this insignificant bit of information forth from every portal. Suddenly there was a big scare about vermiculite being carcinogenic! This is how the info was twisted. You see, asbestos is a cancer causing thing in lung tissue. You probably know this from all the things going on with dust masks in NY, right now. Vermiculite is NOT a carcinogen, but it got such a bad rap from this mine story that some state and even the federal government decided to issue warnings and even to stop production! Most of this was straightened out later, but (like most things) a public statement was never really issued to set the record straight or apologize for the dissemination of falsity. We suffer...

No mine in the US has ever contained a grade of vermiculite higher than #2 in enough quantity to actually profit from it for very long. All #3 and higher has always been imported from Africa or China. This is not cost effective anymore, most likely because of the diminishing use of vermiculite caused by the cancer stories. So the big companies no longer import. Besides, this is a resource we're talking about. Eventually it will run out.
Schultz actually sent me a free bag of their newest line of soil conditioner for free, just to see if it would suit my needs. It's a kiln fired clay that is porous enough to retain water. It may work, it may not. Through experiment, I've found it is very dusty and this dust forms a silt on the bottom of the jar. Not good. It only seems to hold about 1x it's weight of water, as opposed to verm which holds about 10x (then, again verm is extremely light compared to this stuff). The grain size is also too small to allow sufficient air space. Too bad...

In conclusion, I would say you should try to order something large and delicate from an environmentally concious retailer. #4 and #5 are used as packing material (as opposed to styrofoam) by some companies.
Good luck!


If anyone has info on how else to get the chunky stuff... e-mail me! Or post. Thanks.

By Kevin Smith (Canshroom) on Monday, September 17, 2001 - 04:38 am:

The only vermiculite I seem to be able to get I highly suspect is coarse, although the bags are not marked. How can you tell the difference between the grades? Are there set measurements for each grade? Or are there alternatives to vermiculite for the inoculation stage. Thanks in advance.

By saluras (Saluras) on Monday, September 17, 2001 - 11:25 pm:

i can't even get coarse grade. the only stuff i get is like sand. it s a pain trying to get the water right.

with coarse you can always grind it smaller :)

By Karna (Karna) on Wednesday, September 19, 2001 - 11:42 pm:

Here's a good way to tell. Go to, click on growing tips and teks and then on cobweb mold. There are some real close up pics of cobweb growing on the verm seal. click on any of these. All of them are medium grade verm. That or a touch finer is fine for pure verm casing. BTW coarse verm works fine for the verm seal (top inch of pf jars) as well as for casing as long as it is mixed 50-50 with peat moss or potting soil.

By ion ewe (Ion) on Thursday, September 20, 2001 - 06:52 pm:

What is the brand of vermiculite? How big are the largest grains? You may not need to make it smaller. Also, who's ordering it for you?

The fine stuff should be avoided only because it doesn't allow enough air space. You want the brown rice powder particles to adhere to the chunks of verm, but still have air gaps around each chunk. The mycelium needs space to grow between the particles and oxygen to breathe. The lack of these factors inhibits growth, lengthens colonization time, and can possibly affect overall biomass of mycelium negatively. The end result is not necessarily lower yeilds, but a higher possibility of contamination and slower fruiting.

You CAN use the fine verm as the top layer (contaminate barrier) but it isn't necessary.

Read my post under "Vermiculite Options" on the grower's page. It'll tell you all about vermiculite.


P.S. I tried to post this to the other thread, but my computer seems to hate this site or something.

By jim brown (Shrhobbyist) on Thursday, September 20, 2001 - 12:23 am:

I take coarse vermiculite (only kind I can usually find) and put it in the blender. It turns to about the size of sand and is 1/4 the volume of the unblended coarse stuff. The blended stuff is smaller than the fine vermiculite I have occasionally found at the store. Is this too fine? Can it be so small it defeats the water retaining purpose of it? Has anyone used this very fine blended vermiculite and how does it compare to other sizes/consistencies?

By ion ewe (Ion) on Thursday, September 20, 2001 - 03:47 am:

Yes, it does lose some of it's holding capacity. And, yes, it's probably too fine. Remember the golden rule of filling a jar: Don't Tamp it down! The really fine stuff tamps itself...

And where are you getting this coarse verm? How coarse is it? Tell me. Yessssss.


By jim brown (Shrhobbyist) on Thursday, September 20, 2001 - 10:03 am:

Ion, thanks for the vermiculite info in your other post. I have been able to find the coarse stuff (as coarse as it can be) in an 18 pound bag (5 feet tall, 2x2 feet wide) at garden supply stores. If you ask them they will order it for you (from my experience) it's about $15. So, how much will the silty stuff affect my yeild (percentage wise) compared to a coarser grade? And, finally, how can I get the coarse stuff finer without making it too fine? I put it in the blender on the lowest setting and it makes it silty.

By The Silly Scybe Scribe (Toadstool_God) on Thursday, December 27, 2001 - 04:49 am:

It seems to be that the powers above are plotting against me. After agonizing over the wait for my spores I am once again stopped. By what might you ask. I can't get any damn vermiculite!! Nowere in my small town stocks it at the momment. Is there any other substrate I can use that involves ground brown rice and somthing? I live on a farm...anything else I can use with brown rice that I might find around here. Here's an off the wall suggestion as I have bags of it lying around. Potting soil mixed with brown rice? Any suggestions will help. everything but my last ingrediant. Thanks.

By Fishy1 (Fishy1) on Thursday, December 27, 2001 - 05:06 am:

You can use cooked rice in jars like cakes. Check in the "archives"--9er Tek, I think.
Nuecrew has had great luck w/ it I think.
Also birdseed(millet) 5$ for 50 #s at the feed store. see the post next to this one.
Somebody link him up, I am hopless heeeeeeere---fishy1

By Nan (Nanook) on Thursday, December 27, 2001 - 05:56 am:

Vermless Teks

By Fishy1 (Fishy1) on Thursday, December 27, 2001 - 05:58 am:

thanx big guy.

By skabb (Skabb) on Thursday, December 27, 2001 - 09:52 pm:

you can use some shredded sponge instead of vermiculite(i use it). just shred (not to much at a time)some sponge in a mixer and add the rice to it. you must add more water to the substrat.

it works with some crush paper too! a frend try it(with P. Equador) and the mycelium was very rhyzomic. The cake has done ~20 beautiful shrooms on 2 flush.

if you use one of these 2 teks, don' t pack the substrat at all!

that all.(i couldn' t find some vermiculite too! I have find '', they sell some fine vermiculite(for france..i don' t know for other destinations..).

By An guy (Boomer) on Monday, December 31, 2001 - 08:14 pm:

Took some prints, made some syringes.

Having to experiment with corn cob grindings, can't find verm anywhere within about a hundred miles, which is ironic, since I live in the same state as one of the worlds few verm mines....

Anyways, so I'm learning a new jar method with these materials, but what I wanted to say was thanks to all who've advised me on jars, print taking, and syringe making. It's a sweaty endeavoer, always paranoid of contamming, but I shot some jars, and the ones using the last of the verm for a straight pf tek are popping fluff dots great.

I'm very happy about that, proud of myself, and thanks to you folk is how I done it.

Thanks. :)

By quote: (Quote) on Tuesday, January 01, 2002 - 12:05 am:

when corn cobs fail you, try sponges. i hear they make a pretty decent substitute, but you have to use more water. some guy at shroomery used to preach corn cobs, but no one ever got it to fruit...

By An guy (Boomer) on Tuesday, January 01, 2002 - 04:44 am:

Can you tell me what you saw tried? I've already made several false starts, eliminated several techniques, and now think I might have the way.

If not, yeah, the sponges are next. Just hate that idea, want to stay less synthetic.

Hah, he sez, knowing what kind of corn is grown these days.

By Imok Urok2 (Imok) on Tuesday, January 01, 2002 - 05:18 am:

Hey Boomer, If you want to get Verm, and can't find it local,
check out Sources of Vermiculite And Perlite
Hope this helps :)

By An guy (Boomer) on Tuesday, January 01, 2002 - 05:42 am:

Hey thanks Imok- I been ignoring that stuff, I don't buy online for any of this, so I didn't notice the 800 numbers and mail order part.

I think I'll give them a try, and thank you for the link and research.

Reckon I'll still experiment with the cob grindings though, they got my back up with lots of failures.

This is what I'm thinking and fixin to try Quote- wetted layer on the bottom, not immersed, but swelled with water. whole grain above that. Dry layer of cob on top- wet will sprout cob-web, I just noticed how appropriate that was, and trich, I've found out. And dry is hard to shoot. So, use a dry barrier layer, making it some thicker than if using verm, making a smaller cake, using less substrate. Dulled needles seem to thread through the cob easier for knocking the jar up, and you can't pack it right up to the lid either, gets too tight to thread a needle.

So that's what I'm fixing to try. You are right, every other approach I've tried with this stuff has failed.

If this dont' work, I'll scrap it. I'll be ordering some verm now from portland, but still would like to get this cob thing to work, just because.

Thanks again Urok

By Imok Urok2 (Imok) on Tuesday, January 01, 2002 - 06:54 am:

No problem Boomer :)
If you wanted to get real tricky, you could use (for numbers in the US)
Smartpages phone number lookup
to find garden stores in other parts of the country,
call them and see if they have what you need (and will ship)
and order different parts of what you need.
That would confuse your trail and it wouldn't be obvious
what you are doing, as if you bought everything in one place :)
Bet if you made enough calls, you could even find a cheap deal
on a PC or other parts that you might have a hard time finding locally :)

By Hatcher (Hatcher) on Tuesday, January 01, 2002 - 08:46 am:

Yea Boomer, I'm curious, where in this country could you live that vermiculite isn't readily available? That's any Wal-Mart, as friggin' wide-spread as herpes best I can tell. Out west probably? Think I'd rather get herpes than go to Wal-Mart...

By quote: (Quote) on Tuesday, January 01, 2002 - 03:10 pm:

the other people i've spoken with say that mycellia will start on cob, but usually only grows a little then stops. no one ever got any to fruit that i know of.
dunno why, exactly.

By An guy (Boomer) on Sunday, January 06, 2002 - 02:34 am:

Hatcher- actually, I live not too far from an actual verm mine, but it all gets shipped south to be processed. We got the walmarts here, but I've been to 3 cities now looking there and garden shops and nurseries, hardware stores, etc, nothing. Probably get back up in the spring, long about Feb- March or so. So, I'm working on whole grain, using cob for buffering zones-

Wetted, expanded layer on the bottom, loose whole grain in the middle, and a dry layer on top.

I just got this worked out after many failures using other cob approaches, and am going to steam and shoot a bunch of jars. I steamed a bunch a few weeks ago, but didn't knock them up. I wanted to see how long they'd go clean, and it isn't bad- they used inferior tek though, too much water. I think these new jars will do ok, have to just do it and see. I did shoot a couple just for shits and giggles, and man, loose-loaded whole-grain br, once those spores take off, they flat out haul. Got big airspaces and they go like cobweb trying to reach the next food source.

Like I say, I'll see what happens, and post if it's good.

Oh yeah, gotta dull the needle too, shooting through an insulating cob layer, and don't pack it too tight or the needle can't weave through it. It doesn't work as well as verm, but it should get me through till I can either order from one of the sites provided above, or verm gets re-stocked again locally.

baking it helps in grinding it down some, so it's not as large and is a little more like medium verm..

thanks for the info quote- I ahd forgotten about this thread for a minute.

By An guy (Boomer) on Sunday, January 06, 2002 - 02:39 am:

shit, forgot- yeah quote- that inhibited growth was one of the reasons I decided to try them- in a compost pile, corn leaves, cobs, silk, it dont' rot, it's somehow anti-fungal and anti-bacterial, so I figured it'd be a great top layer.

I wet some and let it sit for several weeks now- it's got some cobeweb on it, but nothing like it would if it had any food value.

Initially tried it in the substrate, but that don't work. For me, it's more textural reasons, I havent tried to fruit it. Like I say, I'll post if it's any good for the buffer zones. The bottom buffer- the idea is it's coarse, excess moisture can collect there, and the myclia can dip into it if needed, or not if not. Should know in a few weeks.