Vermiculite

Hello everyone! During the winter I like to read books about gardening and look at all of the seed catalogs that come in the mail. I do not like winter. I wish it was spring already. One book that I am reading right now is Square Foot Gardening. I have a lot of raised beds in my back yard and am very interested in what this guy is writing about. One thing that I am wondering about is his soil mix that he recommends. He says to use 1/3 peat moss 1/3 vermiculite and 1/3 blended compost. The vermiculite is suppose to be a course grade. Has anyone ever used this soil mix? I have never heard of using vermiculite and was wondering what your thought were on its use in the garden. I am not sure if I want to use the peat moss but I am interested in what people have to say about the vermiculite.

Lissy

I think it depends on the soil you are working with to start. Many here would recommend against peat because of the possible Ph factors and also the questions about using such a resource-intensive product. I would suggest that you look at the soil needed for the plants you want to grow, and create that. Remember also that methods can be combined. If you are starting months ahead, you might combine sheet composting (a.k.a. lasagna gardening) with the square-foot designated beds.

Lissy, earlier editions of the Square Foot Gardening book do not include the "Mel's Mix" that you describe and just have gardeners do the square foot planting on their amended soil. SFG is primarily about how you plant your crop within each square, protecting your plants as needed using row covers or shade cloth, and growing verticially to save space.

I would use your native soil and amend it with compost and any nutrients that may be needed. If you still want to use the new mix recipe, you can substiture coconut coir for the peat moss. It is more cost effective if you buy the coir in a dry 'brick' and rehydrate it yourself. The coir is a more sustainable solution and won't deplete the native peat beds.

We follow an intensive square foot planting scheme that is a cross between Mel Batholomew's plans and John Jeavon's designs. Our raised bed garden contains the native adobe clay soil amended with a lot of compost, some rock dust, sand, coir and guano in the first season, then cover cropped with a cereal-legume mix afterwards. When we lived in the Sierras, our native soil was ground granite and pine needles, aka "moondust". We amended that with compost, manures, some clay and cover crops. Some plants like sandier soil than others. You can customize what goes in each square foot, or amend the whole bed and mark off the squares later.

Thanks for the info. I am very hesitant about using Peat moss because it is such a resource-intensive product. Peat moss would actually be a good thing to put into my soil because my soil here is very alkaline, but I don't want to use it because I don't want to contribute to depleting the native peat moss beds. I have heavy clay soil so the compost that I have been using has helped a great deal. I was just wondering if the vermiculite would help break up the clay further. Maybe I will just stick with using my compost I have been making.

Garden Mermaid~ I have never heard of using coconut coir. Does it help acidify the soil like peat moss? Thanks for the tip. I will have to look into that further to see if it might help my gardens out.

greenjay~ I have been reading a little about sheet composting. I am going to have to give that a try. I appreciate your reply to my question.

Lissy

My initial raction to beds made of 1/3 vermiculite, 1/3 peat moss, and 1/3 compost is it sounds expensive, depending how big they are. But that's just me...

Try searching 'vermiculite safety', or 'vermiculite hazards'. At least some vermiculite was associated with asbestos. Maybe it's better now, maybe it's not, depending who you ask. The dust is at least potentially hazardous, especially when mixing it. I'd wear a dust mask, or avoid it. My two centavos

Coconut coir is supposed to be pH neutral. Gypsum also helps break up the clay.

It is cheaper to buy the coir in blocks and rehydrate it yourself. We paid $11.00 for large block at a local hydroponic store. They also sell it hydrated in bags like soil, but you really pay a premium for it that way. You may be able to find the blocks at you local garden center. Here's a link with an example of the way coir is sold.
http://tinyurl.com/yx66ym

Here is an article comparing coir vs peat for horticulture uses in Florida:
http://www.imok.ufl.edu/veghort/pubs/sta_rpts/967.pdf

The coir also makes great bedding for worm bins.

There is also a 'faux peat' product made from dairy cow manure called RePeat. I have not used this product yet so cannot say how it does. Here is a link with more information:
http://www.organix.us/product/repeat/

I use vermiculite mixed with potting soil to start my germinated seeds. Several months ago I read about SFG and tried the recipe for peat moss, vermiculite and compost. (I substituted potting soil for the compost.) The peat moss made the mixture dry to a brick-like state. Lost all the plants I had potted up with this mix. A failed experiment on my part. I'm planning to try setting up the lasagna bed system this winter.

I never have used vermiculite myself. My soil is very rock and quick draining so I do not need more broken up are air in the soil. I am fortunate to live in a area where ther are many turkey barns and buy composted turkey manure by the pickup load cheaply. There is a place north of me that has a professional composting operation. They use a drum 10 ft in dia and 50 ft long. It compost 55 tons at a time. They also grind up coencobs to about the size of pea gravel and mix it in in some cases at 50/50. He sells tons and tons of the stuff to farmers and ships some by big 18 wheelers oar haulers. If your soil drains fast I am not sure Vermiculite would be a goos thing.