Raised Garden Beds

We are building rasised garden beds this year instead of just planting in our soil- I am trying to determine the best soil mixture for the beds.

I was planning on following Gardening by the Square Feet in which the author advocates 1/3 vermiculite, 1/3 peat moss and 1/3 compost, however, the only vermiculite I can find is the stuff for attic insulation and even though an Internet discussion board says it's fine, I am concerned since the reason I am using raised garden beds is that we are planning on feeding our toddler the produce we grow and I am just not confident about the vermiculite.

Does anyone have a good receipe what to use in the raised beds?

Thanks,
Susan

Susan, I have only read a bit about the vermiculite concerns, but seemed to think that what is available is OK now. Did you find information that shows it's unsafe for growing food? I use it (and have for many, many years) and haven't been concerned, but as I said, I haven't read that deeply as what I read awhile back put my mind at ease (can't remember why it eased my mind...). I seem to remember vermiculite was even listed as in ingredient acceptable for growing organic foods (not the be all and end all, but seems to indicate it isn't harmful - but maybe organic is only concerned with environmental damage).

I'd like to know if I should revisit this concern. All members of my family, including kids, eat what's grown in the mix I use. So, please, let me know what you found that shows it's dangerous, especially to kids.

There are a lot of potential mix "recipes" out there; the Square Foot Gardening mix is similar to what's recommended to use in any container gardening. They are all similar in one regard, that they all use a soil-less mix of peat, vermiculite, perlite, and/or compost as the main ingredients. Perlite is the most common sub for vermiculite, so that's one way to go.

The only stuff I could find was this attic ventiltation stuff sold at Menards and recommended by a Garden Web site. There appears to be some concern with some stuff made 20+years ago, but I just wanted to see if there were other options since I had never heard of vermiculite before.

The perlite/vermiculite topic was pretty well covered here last year in a thread on planting mix for square foot boxes.

So based on this, should I still use the vermiculite or use something else?

Thanks,
Susan

Have you had a change to read through the other thread? There are no straight suggestions, but it seemed to me that:
a) vermiculite used for insulation is treated to resist water, when in the garden, you want it to retain water
b) the problem with vermiculite is not vermulite, but asbestos contamination in ONE mine that was closed ages ago. So, any vermiculite mined today shouldn't have risks (though it's still not suggested to breath it while working - you're not supposed to breath anything with a lot of dust).
c) some people had problems finding it, but someone found it for the garden at a source somewhere north.

And, we already know that you can substitute perlite. If me, I'd read the other thread, find the source for the vermiculite, call them, and price it. Then I'd do the same for perlite. Whichever was less expensive (cost and transportation to get there) is the one I'd get.

I'd call McDonald's and see what they grow their chicken McNuggets in as that's the only thing my toddler would eat....

I got some big bags of horticultural vermiculite at Anton's in Evanston last year for like $20 each. I think I used 2 in my three square foot garden beds and sold another to stevez.

Places like Gethsemane have perlite but only only in very small containers, making it prohibitively expensive.

I'll keep you updated on the status of my mesothelioma.

In the past I've had good luck box gardening using about 1/2 potting soil combined with 1/4 composted manure and 1/4 garden soil.

Ok, I called Sun Grow, the maker's of the attic vermiculite sold at Menards, according to them, it is the same stuff as the horticultural vermiculute. It goes for 9.99 for 3 Cubic Feet at Menards. I can't figure out why they call it attic verimiculite when it's the same as hoticulural vermiculie.

. According to Sun Grow, they have been testing their vermiculte for years with no problems.

If they say it's the same....sounds good to me. An earlier post mentioned that the stuff for attics is usually treated. That could be the only difference. I wonder if they have to treat it or if that is voluntary...because it would be the same in a way, but not completely.

I found a product called Nursery Mix that consists of a three way blend of soil pep (decomposed bark), peat moss, and compost. I am assuming that the soil pep would perform the same function as the vermiculite. Does anyone have any experience with this for raised planter gardens? I am a little scared of doing a mix that has no soil- how does this stuff work?

http://www.renewablefiber.com/soil_products.htm

I've used many mixes (some I've made and some I've purchases) that have no soil. They work fine, truly.

Amended my response: I was thinking you were using a pre-made mix. I haven't heard of soil pep before. Though it's very light, I am not sure it does what vermiculite does. I am not an expert but thought that vermiculite helps with water retention and does some weird expanding thing that I assume helps with aeration or drainage or similar.

So, while the soil pep would help make a clay soil light, that doesn't seem quite the same as what vermiculite does.

No soil mixes will work, but they are very light and tend to float or blow away.

After calling the following:

Gesthemane
Home Depot
Farmer's Market GC
Adams something GC
CIty somethng GC

And going in person to Lowes and a different Home Depot, not one of them had large quantities of vermiculite. Farmer's Market normally does and it's ordered, but I don't think I want to wait in the hopes that it does come in next week as it's supposed to. Lowes, Adams and City all have it, but in 8 qt bags. That does 1 1/2 EBs, and I have 4 of them along with about 8 various hanging baskets, planters, and bags. So, I'd need to by about 5 of them at $10 a bag.

I finally remembered this thread. I called the Menards on Clybourn. Yup, in stock. I did one last search on horticultural vs attic to verify that the person Susan talked to knew what she was talking about. While I didn't see any information about whether it's generally different, I saw multiple posts on other forums where the people went through the same thing as Susan and eventually determined it was fine. So, I'm off to Menards with my trusty cart. Ah, to finish prepping all my boxes today. That is a good thing.