User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

Has Anyone Used Vermiculite?

I ran out of perlite this spring while prepping the last two beds. The fellow at my favorite garden amendments store suggested vermiculite as a substitute, saying I should use it in the same quantities as perlite to aid in water retention.

I bought the huge bag, used it on the last two beds, and am now beginning fall prep of a brand new bed for next year's tomatoes. I'm a long ways away from amending the soil, but I thought this would be a good time to determine what I purchased, what it can do, how to use it, etc.

Has anyone used vermiculite? If so, what can you tell me about it? How much did you add? Also, its appearance is clearly different from perlite's. I'm not seeing all that big a similarity. Vermiculite appears to lack the substance of perlite, so I'm doubtful about its water retention capabilities. Any thoughts there?

Thanks :!:

User avatar
applestar
Mod
Posts: 30514
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

I used vermiculite way back when... for potting soil. Vermiculite is "puffed" mica. They compress back into the flat shiny flakes VERY EASILY. I don't recommend it.

FWIW, both vermiculite and perlite are heat processed and "sterile"/can be made sterile. I've always considered perlite as good for drainage (and preferred over sand, etc. by commercial growers because it's lightweight). It retains its shape, though it does crush easily if you step on it. Vermiculite is only useful for holding moisture when/as long as it's puffed. The dry dust of either product can be hazardous to your health.

I'm not sure WHY you're using either of these products in outdoor garden beds. I've always thought of them as potting soil additive. As long as you're adding compost, you don't need anything artificial to retain moisture.

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

About vermiculite from Clean Air Gardening: "This soil additive is formed by heating particles of mica, a natural ore. The heat causes Mica to expand, which makes it extremely porous. The advantage of Vermiculite is in its ability to hold nutrients, boost soil moisture, and aerate the soil."

That's why I'd want to use it. Besides, I love experimenting. IMO, last year's garden should never be as good as next year's. If we stick with the same old soil prep, plants, fertilization, et al, we deny ourselves the chance to succeed beyond our wildest imaginings. Sure, compost is best, but our soil can always be better, higher in nutrients, more friable, better in retaining moisture, better able in all ways to satisfy the plants' needs.

One thing I most enjoy about gardening is the endless opportunities it offers us all to improve our skills and see quantitative and qualitative results in a matter of months. Yeah, I've had flops, but I learn from my experiences and move on, one step closer to that magical garden that is perfect in every way.

Actually, I hope it never happens. Everything would be boring after that! So, I'm trying vermiculite in next year's beds. I've had great success with perlite, BTW. Maintaining moisture in this dry climate to a depth of two feet can be problematic. It can also result in unnecessary utilization of another precious resource: water :D

cynthia_h
Super Green Thumb
Posts: 7500
Joined: Tue May 06, 2008 7:02 pm
Location: El Cerrito, CA

Very little time tonight: I used vermiculite in the Square Foot Garden beds last year. It is great!!!

Vermiculite + mixed composts + (?) peat moss... woulda been better with just the first two.

Go for it!

Cynthia, on drive by

User avatar
applestar
Mod
Posts: 30514
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

But... I'm telling ya! :bouncey:
applestar wrote:They compress back into the flat shiny flakes VERY EASILY.
...
Vermiculite is only useful for holding moisture when/as long as it's puffed.
Stella, I didn't intend to sound critical (of you and your efforts), and I apologize if you perceived my post that way. I applaud your enthusiasm with all your experimentation. But you did ask for peoples' experiences, and I found vermiculite useless and perlite -- AND peat moss dust for that matter -- chokingly unhealthy. Perlite in particular, the dust is considered a health hazard and a respirator is recommended in the MSDS.

ETA: Oh here we go. I KNEW Vermiculite dust is/was also considered health hazard -- "Although not all vermiculite contains asbestos, some products were made with vermiculite that contained asbestos until the early 1990s."
Read the rest at: https://en.wikipedia.org/wiki/Vermiculite

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

I didn't find it critical, Applestar; sorry if it sounded that way. I began using perlite when I was living in Cheyenne and having a problem with tomatoes cracking. No matter how frequently or regularly I watered, the moisture evaporated quickly in this dry, dry air, from surface on down, causing the soil to dry up equally fast, and my tomatoes split.

Once I began using perlite, the problem significantly lessened. Perlite holds moisture in. When the soil around it has dried, it can draw upon the moisture in the perlite to replenish it. Watering can be less frequent, and water is conserved. The plants like its ready reserves; the environment likes the lessened use of water: win-win.

As for the dust, inhalation of virtually any dust can be harmful. I was tossed from a horse once, landing flat on my back and emptying my lungs in one big "oooomph!" I lay there, gasping for air, air that was dusty because of my fall. A week later, I was in the hospital with pneumonia. I can't say the fall caused the pneumonia, but I don't believe in wild coincidences, and I think it did :lol:

Based upon my use of both, perlite is, without a doubt, the dustiest. Whenever I added it to the soil, I had to take care not to breathe while scooping it from the bag. However, once mixed with moist soil, there is no dust.

I've never had dusty peat moss. The stuff I buy is moist, so I can't speak to that.

You wrote
"Although not all vermiculite contains asbestos, some products were made with vermiculite that contained asbestos until the early 1990s."
I don't think my vermiculite could be that old :D

Thanks for you comments, Applestar. I was hoping someone could advise me on their successful use of vermiculite. I think I'll just go with the 10% mix I used with perlite. It's fun to plan ahead!

top_dollar_bread
Senior Member
Posts: 203
Joined: Fri Jun 26, 2009 5:34 pm
Location: Inland Empire,CA

Vermiculite and perlite are great for helping build soil texture. Its soil texture and a diverse micro herd IMO that makes a good growing medium.
I don't add vermiculite or perlite when pepping my garden soil, but I do add it to potting soil.
I'm with AS,
I prefer to add sand,humus or composted organic matter, to build garden soil texture.
But I also understand stella’s lust for experimenting to better ourselves as gardeners.

To me Good soil is good soil, weather it be potting soil or garden soil. The best soil for most of my crops, would be classified as a loam texture.

Loam texture soils contain a balance of differently sized particles (sand, clay, silt, pebbles) and organic matter. Clay and silt are tiny particle in size, sand is larger, and pebbles larger.
I classify vermiculite and perlite as pebbles, or sand.
Its important to observe your perlite vermiculite, ive seen tiny perlite/ vermiculite that looks like dust/sand(mostly at the bottom of the bag) and larger perlite/ vermiculite that resemble larger pebbles in size.

A good loam soil contains a balance from each category, in roughly equal measure. So when I'm building any soil, I try to aim for a nice balance among the textural elements.

Soil Texture
- Sand or tiny perlite/ vermiculite particles 1 percent
- pebble sized Perlite/ vermiculite 2 percent
- Peat/organic matter 6 percent
- Grit or medium to coarse texture matter, 1 percent

Each component (sand, grit, organic mater, even pebbles of the mix can also be used to enrich the soil as well as build texture)
For instance, instead of just adding sand or tiny perlite/ vermiculite we could add greensand, gypsum, and ground lime witch also provide K, S, Mg, Ca, trace minerals; pH buffering and each represent a different texture/particle size.
Instead of straight peat moss we could add mushroom compost, worm casting, composted manure, garden compost, guano etc for inoculating with microorganism as well as balanced slow release nutrients.
Instead of granite/grit we could add kelp meal, rock dust, and alfalfa meal for N,P,K, trace min, growth hormones, enzymes, etc.
I was hoping someone could advise me on their successful use of vermiculite
Its all about balance and finding that balance. Gardeners that don't have this balance may have difficulties with some ingredients.
For example AS doesn't recommend vermiculite and I believe I read that cynthia_h has had some negative experiences with peat moss.
But to me if you buy quality products and use a balance strategy when mixing soil, I find both products to be very successful.
Has anyone used vermiculite? If so, what can you tell me about it? How much did you add?
Most of my experience in gardening has been obtained with growing in containers and most of my soil experimenting days were done will soilless potting mixes. With soilless potting mixes I have found a great recipe that I follow, witch works for many of my plants that I grow in containers.

5 parts peat/coco
3 parts perlite/ vermiculite
2 parts composted manure or EWC or fresh homemade compost etc (organic matter)

to every gallon I add
1-2TBS pulverized (powdered) dolomite lime.
And 1 TBSP of kelp meal

this is the base of my soil and what gives me the texture I like. Some of the ingredients vary in texture and quality so a texture test is applied to sure of its quality.

To test for good soil texture, you want to moisten the soil being tested (don't soak moisten). Take a good handful of the soil and squeeze as hard as you can. Only a few drops to zero drops of water should come out, but it should form a clump shaped by the ridges of your fingers. (this is what you want)
Now you should be able to loosen the clump lightly with your thumb or finger and it should fall apart easily.

If the soil resists clumping it is too loose and needs more organic matter to bind it together. If the soil resists breaking apart once clumped it is too dense and needs more perlite to prevent compaction.
Remember roots want both air and water, thats why I believe this balance is so important. Also some plants prefer different texture and drainage, so be creative and experiment.

After I'm happy with the texture I then mix and add certain macronutrient amendments according to my knowledge of what the certain plants require.
Nitrogen is added by either or High N guano @ 1 TBSP, Blood Meal @ 1 TBSP, Alfalfa Meal @ 2 TBSP, or Fish Meal @ 1-2 TBSP to the gallon of the above mix.
Phosphorus is added by either or Bone meal @ 2TBSP, Soft rock phosphate @ 2TBSP, Fish bone meal @ 2TBSP or Phosphorus rich guano @ 1TBSP a gallon.

Potassium is added by either or Kelp meal @ 2TBSP, Alfalfa @ 2TBSP, Greensand @ 2TBSP, Guano any @ 1 TBSP a gallon.

The great thing about most organic amendments is that they also supply many trace minerals, micro nutrients, hormone and vitamins as well. These are also important when trying to build a healthy soil. Theres almost endless organic alternatives when building soil, weather it be in the form of texture, supplying nutrients, or micro organisms.
I only outlined amendments that I have had experience with but I'm sure ther are lots more.

But out of all of these compost and organic matter are to me the most important. Garden soil can get all its essential nutrients threw compost and organic matter when adding as a top dress. I tend to avoid disrupting my soil and add ingredients to first 2 inches of the surface of my garden soil. This is why I tend to not add perlite/ vermiculite to my garden soil, I like to let the microbes be.
Vermiculite does help aerate the soil, just like perlite. But vermiculite IMO retains moister a lot better, but again balance is key. I don't use perlite any more, simply because the dust that most of you guys mentioned.
A good idea would be to soak the perlite with water before handling.
The dust is really bad stuff to be breathing; I find that the vermiculite I use doesn't have this dust.
What I like about both products thought is that they both seem to accumulate microbes. Ive noticed that my perlite and vermiculite, when mixed with soil, gets stained with a dark brown humus. I also noticed that it doesn't wash out and instead stays stained. I have come to believe that in the pores are microbes and that's what is causing them to appear stained. So what I like to do, is soak either or perlite/vermiculite in my compost tea.
This gives them a nice stained look and if my hypothesis is correct, then my perlite vermiculite are now also considered inoculants…just a thought, I hope this helped

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

Very interesting, Top_Dollar_Bread! There's some fascinating information in here. For me, gardening is always about the soil. I like playing with dirt, always have. I like the feel of it, and I like creating a welcoming environment for the plant roots.

Today I picked a 5-gallon pail of squash for my second cousin. There's never any joy in the harvest for me. It's a necessary thing to do because it contributes to the health of the plant. I am certain that is an odd thing to say, but I'm all about playing with dirt. The harvest is only incidental.

Oh. The look on his wife's face was nice--she has problems digesting regular produce, and organic produce is tough to find here. Squash is her favorite veggie. I don't think her smile could have been any broader. Made me feel good.

When I returned home, I went out and played in the dirt :lol:

User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

I saw a garden show on TV and the guy mixed in some powder called sodium polyacrylate same stuff that is in a baby diaper. Mix sodium polyacrylate with dry potting mix and it will adsorb 300 times is own weight in water, and it will hold the water. Works great for starting seeds and potted plants according to him. I have not tried it yet.

The Helpful Gardener
Mod
Posts: 7491
Joined: Mon Feb 09, 2004 9:17 pm
Location: Colchester, CT

But this is an Organic forum Gary, and that stuff is completely synthesized, with NO studies (not to mention it's mostly sodium) yet on long term effect on polymers in the soil (Breakdown components? Recombinant chemicals? Still a mystery...)

Vermiculite is natural, but it is mica heated at VERY high temperature with fossil fuels, so maybe not so green? I still like compost...

HG

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

HG wrote: Vermiculite is natural, but it is mica heated at VERY high temperature with fossil fuels, so maybe not so green? I still like compost...
Not green but organic. I just like playing and experimenting :lol: I will use up what I've got in the new bed I'm building. I probably won't use it again--it was a desperation We-don't-stock-perlite-anymore purchase--unless something truly odd and wonderful happens! I will go back to my perlite afterwards.

I moved here from Cheyenne, WY. Because of that city's close proximity to Fort Collins and because of its western, rural flavor, many city dwellers are choosing it as a base, driving from there to their jobs in Fort Collins and, in extreme cases, Denver. The city is growing like mad.

Unfortunately, it doesn't have a natural water source, not like Casper. While living there, I watched the population go from 50,000 to 60,000 in eight years. My elderly gardener friend told me the city's water source will only support 50,000. I started thinking hard about water conservation while living in Cheyenne. Now I'm addicted.

My huge bag of vermiculite or perlite may use up an ounce or two of fossil fuel to create, and I won't let myself think about the type of mining that may have been used to collect it, but just think of the water I may conserve by using it. It won't degrade. It will always be there. The water I'm not using will be, too :D

One day, I want my own sandpoint well in my backyard. Dream, dream, dream 8)

The ancient Greeks preached all things in moderation. Excess in anything was held to be bad. We are organic gardeners. If we forego anything that uses fossil fuels to create, we will be watering our gardens from wooden buckets with rope handles and turning the soil with dibble sticks. There are trade-offs we must make for the benefit of the plants. (Had you told me earthworms hated vermiculite, I would have tossed the stuff in the dumpster!)

Next to the soil itself, compost is the biggest ingredient in my beds. I'm a big believer in compost. I imagine I use 500+ pounds each year in my 240 square foot garden. However, I throw in many odds and ends, too, things I want to try, things I've had good luck with before. Gardening would bore me very quickly if I couldn't shake it up a little :cry:

User avatar
Morning Light
Full Member
Posts: 12
Joined: Mon Nov 02, 2009 9:04 am
Location: Iowa, Zone 5

I have to agree with the "Helpful Gardener" that vermiculite is an inorganic solution to an organic gardening problem; the dust does pose some risks to the respiratory system.

For me, compost is a wonderful way to get the tilth a gardener desires in soil. I can't comment on container gardening.

I do use vermiculite to store bulbs over the winter. It works wonderfully well for small bulbs like Caladium and Acidanthera; put some in a pot, bury the bulbs in the vermiculite and store in a cool somewhat dry place. Works like a charm! I haven't tried it for dahlias, but maybe next year.

One more comment: I bought a new, small bag of vermiculite for a ridiculous price. It cost about 5x more than a bag of compost 3x its size. Where IS the inflation in gardening supplies coming from?? Grrrrrr!

Emma

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

Morning Light wrote:I have to agree with the "Helpful Gardener" that vermiculite is an inorganic solution to an organic gardening problem; the dust does pose some risks to the respiratory system.

For me, compost is a wonderful way to get the tilth a gardener desires in soil. I can't comment on container gardening.

Emma
The vermiculite is intended to work with compost, not replace it. It's an experiment in enhancing nutrition uptake and, more importantly, water retention. I'm obsessed with using water wisely :shock:

Back in the 1990's, during a long, long drought, South Dakota sued North Dakota because that state reduced the flow on the Missouri. It occurred to me then that our next Civil War will be over water rights rather than human rights. Those states that control the headwaters of the major rivers and their tributaries will not take kindly to being told to release more water downstream, not if it means their agricultural industries will suffer.

During the last drought up here, Cheyenne depleted almost all its reserves. Unlike Casper, Cheyenne has no natural water source and relies almost entirely upon a reservoir. I was living in Cheyenne then, and that's when I began using perlite.

I remember reading something about a lake down in the Southwest not too long ago. Its levels fell to a historical level, and one law enforcement representative suggested old crimes would be solved right and left because of the discoveries that were being made. (That was about five or ten years ago, but I can't remember the lake, maybe Lake Mead?)

I bet California would give its left peninsula for Washington's wealth in water, as would Wyoming for Montana's. I read recently that California is in serious trouble over water, that the agricultural industry there is in dire straits.

Even though I now live in Casper, with pretty much unlimited water sources (unless Colorado dams the North Platte, which would be really selfish of it), my experiences in South Dakota and Cheyenne have made me water conscious. So, I will add vermiculite in an attempt to enhance water retention that I might use less water. I did read that it improves the plant's uptake of nutrition, which would be a bennie, too :D

User avatar
rainbowgardener
Super Green Thumb
Posts: 25279
Joined: Sun Feb 15, 2009 6:04 pm
Location: TN/GA 7b

Many of the conservative Southern Californians would be glad to give up that "left peninsula" whether or not they got much back for it! :)

This is a great discussion with lots of good points being made. I'm trying for the permaculture thing... no outside inputs, garden sustainably with what nature provides on the property. Eventually I'd love to be somewhere, where I could have a few chickens so nature could provide a bit of manure. But in the meantime nature definitely doesn't provide vermiculite!

But I also think we need to be very careful about making almost any general statements without regard for place. Natural gardening is all about working with that spot, its climate, soil, native plants, special requirements, etc. Not trying to grow green lawn in Arizona or tropical plants in Minnesota. Gardening in Wyoming is not at all like gardening in Seattle or San Francisco or Ohio where we have had more rain this season than we know what to do with and the last thing I want is for my soil to hold more of it. I'm very much with stella on the idea that water is perhaps at this point our most precious resource and if we need to do something not quite natural to conserve the water, that maybe the most conscientious choice.

User avatar
Morning Light
Full Member
Posts: 12
Joined: Mon Nov 02, 2009 9:04 am
Location: Iowa, Zone 5

You make very good points, rainbow gardener. My take on vermiculite comes from gardening where the soil is good to excellent and where there is usually too much water (at least in the last 18 years, Iowans often refer to our state as "Lake Iowa" based on the satellite shots that showed the whole state blue during the 1993 floods).

I certainly don't mean to disparage the approaches of other gardeners, having done some rather unconventional things myself. Trial and error is often the only way we discover new methods.

So far, I like this list because because it is not the usual "stuck in the rut" gardening discussion. My goal is to share what I know when I can, taking into account it is one gardener's view from one spot on earth.

Emma

The Helpful Gardener
Mod
Posts: 7491
Joined: Mon Feb 09, 2004 9:17 pm
Location: Colchester, CT

And we're glad your here to do that Emma... :D

Rainbow, sense of place is what gardening should be all about. Linking soil to plant to environment. Very nicely put...

Stella, the "ounces of fossil fuel" is likely gallons; we are heating rocks until they go pop; I have seen many a rock in a campfire loaded with mica (we have lots of schist in this area) and I have yet to see one pop. While fossil fuel consumption is not the sole responsibility of gardeners, I have always thought of it as a good indicator for good gardening practice. Chemical fertilizers? Four gallons to the 50 lb. bag of 10-10-10 in that Haber Bosch process. I use hand tools whereever and whenever I can short of real time killers like taking down a tree or mowing the lawn (won't SOMEONE come up with an electric rechargeable mower I can set at 4 inches?).

Mined, heat processed garden ammendments are certainly a high impact item, when compost actually is restoring carbon to the soil instead of dumping huge amounts into the atmosphere (a pretty well-recognized bad thing to do). If you've got it it already I guess it makes sense to use it up (this isn't a pesticide or like direct damage consideration), but please consider all the effects of any garden product (key word is production) before purchasing. Mining is by nature a destructive process that capitalizes non-renewable resources. That doesn't sound good to me...

And the biggest reason not to do it? Perlite and vermiculites use as a soil amendment has been highly questionable since they were introduced; here's an [url=https://turf.lib.msu.edu/1950s/1952/520429.pdf]OLD article[/url]from 1952, a US Geological Administration article that points out mineral supplements tendency to powder, and most damning of all...
When mixed with a sandy loam
soil even in amounts up to 50 per cent
by volume, they do little to alter the field
capacity, wilting point or available moisture
capacity.
Anybody using this stuff at more than a 50/50 mix? :shock: :lol:

Conversely the compost is a sure thing for many reasons; soil aggregation through polysaccharide generation, capillary action and soil voids from fungal structure and the inherent capacity of humus are the things that really build holding capacity in soils. Using man-made products may make you FEEL better, but efficacious? Not usually...

HG

User avatar
Morning Light
Full Member
Posts: 12
Joined: Mon Nov 02, 2009 9:04 am
Location: Iowa, Zone 5

Enlightening post, HG. Mining IS destructive. If it is any consolation, I reuse the vermiculite year after year for storing bulbs. Not like it's going to decompose.... :lol:

Emma

User avatar
stella1751
Greener Thumb
Posts: 1494
Joined: Mon Jul 13, 2009 8:40 am
Location: Wyoming

The Helpful Gardener wrote:

Rainbow, sense of place is what gardening should be all about. Linking soil to plant to environment. Very nicely put...
HG, given that the most infamous vermiculite mine in the world lies just north of me, in Montana, I think sense of place is present. I read that Virginia and South Carolina are another two vermiculite rich areas.
The Helpful Gardener wrote:

Stella, the "ounces of fossil fuel" is likely gallons; we are heating rocks until they go pop; I have seen many a rock in a campfire loaded with mica (we have lots of schist in this area) and I have yet to see one pop . . . Mined, heat processed garden ammendments are certainly a high impact item, when compost actually is restoring carbon to the soil instead of dumping huge amounts into the atmosphere (a pretty well-recognized bad thing to do).
Agricultural vermiculite is not heated. The stuff I have on hand just looks like teeny tiny mica flakes.
The Helpful Gardener wrote:

And the biggest reason not to do it? Perlite and vermiculites use as a soil amendment has been highly questionable since they were introduced; here's an [url=https://turf.lib.msu.edu/1950s/1952/520429.pdf]OLD article[/url]from 1952, a US Geological Administration article that points out mineral supplements tendency to powder, and most damning of all...
Here's a [url=https://www.ask.com/bar?q=what+is+vermiculite&page=1&qsrc=0&dm=all&ab=8&title=Vermiculite+Home+Page+for+Information+about+Vermiculite---A+Mineral&u=http%3A%2F%2Fwww.vermiculite.net%2F&sg=jwFdcYtJKYFwrk8YC7FJLKkE1ojgP6k3OZe8Jz3M4bo%3D&tsp=1257381765224]newer link detailing a 1980's experiment[/url] in Brazil.
A quote from the article says,
"[In this experiment] Fertilizer was applied in a similar way all over (NPK 4-30-10), at the rate of 220 kg/ha. The plot that had vermiculite showed a production of 1.575 kg/ha as against 1.221 kg/ha. This means an increase of 29% in productivity!"
I've gotta be honest with you, the more I read about this, the more I like it! I don't like that it is mined, but I don't know about the type of mining used, so I can't criticize it blindfolded. There are responsible mining companies out there, companies that leave the land better than they found it.

I think I am making a choice between unnecessary water consumption and the fuel it takes to extract one bag of vermiculite, create the bag, and ship the bag. I seriously think the water wins out. The vermiculite will last for decades, if not longer. The water savings will be on a daily basis during our hot spells.
The Helpful Gardener wrote:

Anybody using this stuff at more than a 50/50 mix? :shock: :lol:
Ditto that, HG. I'm guessing I mix mine at roughly 1%, but I can't be certain without doing the math. If anyone out there can figure what percentage five large trowels of vermiculite are in a bathtub full of amended soil, that's my mix. Sometimes I use six, but only if there are two partially full trowels. I can guess the trowels would fill a two-quart pitcher.
The Helpful Gardener wrote:

Using man-made products may make you FEEL better, but efficacious? Not usually...
You know vermiculite is a natural mineral, right?

So, here's the scoop: Vermiculite occurs naturally in my part of the country. It is a mineral, not a man-made product. For agricultural processes, it is not heated. It assists in water retention and, if you read the article at the above hyperlink, it actually has demonstrated an ability to lessen nutrient run-off during wet spells.

Best of all, the research I did to counter these arguments showed me how to best use it!

I think poor vermiculite is misunderstood. I see many, many misconceptions about this mineral. I think the Libby, Montana, debacle is to blame, though, so I can understand that :lol:

The Helpful Gardener
Mod
Posts: 7491
Joined: Mon Feb 09, 2004 9:17 pm
Location: Colchester, CT

Hey Stella,

Thanks for all the homework; I had always thought of vermiculite as the puffed stuff and had no idea the raw form had uses in the garden (I WAS aware it is a natural mineral; I just think mining to grow things is a bad idea. I don't like mined humates either, as we can create humus with local plant detritus in a far more earth-friendly manner).

I had not thought about it from an increased Cation Exchange Capacity POV, but I guess I shouldn't be surprised; clay is a good example of another mineral that really increases CEC (ability to hold nutrients). That could explain the boost in growth and harvest. I was referring more to water retention than fertility, but this is good to know. I also remember somebody telling me about using stone base in bonsai soil; something about the sharp particle increasing hair rooting. Increase in root mass might help account for some boost as well. Likely a combination of factors, but I am still certain increased field capacity isn't it.

I guess my question would be why mine when we can get increases in CEC from waste sources like stonecutting? Granite counter-tops going into houses like nobody's business; [url=https://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VDG-45BCR16-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1078643528&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=97bd05d28d9c26cb8d8fc4632eaa9abb]granite can do all the above[/url]and adds potassium too! Rather than a big hole in the ground we utilize what has been garbage to date. Actually volcanic ash is the best mineral for increasing CEC, and Mother makes more all the time; no need to poke a hole in her there either... :mrgreen: Is perlite or vermiculite natural? Yep. Organic? 2 for 2. Do we improve it's effectiveness processing it? Nope. Is it greener than chemical fertilization? Hey-yeah it is. Is it as green as we can get? :?:

HG

User avatar
Sage Hermit
Green Thumb
Posts: 532
Joined: Fri Mar 13, 2009 4:20 pm
Location: Finlaysen, MN Coniferous Forest

What about coco? and coffe grinds?
:o :lol:

How can I use those?

The Helpful Gardener
Mod
Posts: 7491
Joined: Mon Feb 09, 2004 9:17 pm
Location: Colchester, CT

Lots of stuff in the [url=https://www.helpfulgardener.com/forum/viewforum.php?f=35&sid=2f5ac2e151716f7414a75985de652caf]Compost forum[/url]on those topics, Sage. Try using the search box at the top of the page and you will pull up tons of stuff on both, I am sure...

HG

User avatar
Sage Hermit
Green Thumb
Posts: 532
Joined: Fri Mar 13, 2009 4:20 pm
Location: Finlaysen, MN Coniferous Forest

Sorry and thanks.

emerald7
Cool Member
Posts: 78
Joined: Fri Feb 19, 2010 1:13 am
Location: Houston, TX

I am about to use some vermiculite in the soil of one of my plants, and today I was reading about vermiculite's effect on PH. It is billed as 'sterile', but apparently it tends to have an alkaline effect in soil media (from 7.0-9.5 PH). So it depends on what you are thinking to use it in--if it's a neutral to alkaline-loving plant, it's fine but if you are thinking to use it in an acid-loving plant, you might not want to do that. HTH.

The Helpful Gardener
Mod
Posts: 7491
Joined: Mon Feb 09, 2004 9:17 pm
Location: Colchester, CT

Thanks Emerald!

HG

Toil
Greener Thumb
Posts: 803
Joined: Tue Jan 05, 2010 4:18 pm
Location: drifting, unmoored

I'm going to sheepishly admit that I use the stuff for starts and rooting cuttings. I'm gonna try some swamp rose this year, maybe a dozen, and spread the swamp rose joy at my community garden before moving away.

I really should be using something more environmentally friendly.



Return to “Organic Gardening Forum”