You should go to your local library and get the book "Square Foot Gardening" by Mel Barthalemew - spelling may be off. He tells you how to have the perfect gardening soil from scratch. It's very easy and well worth the little effort you will have to exert.
He's changed his ideas about several things over the past 25 or 30 years so the original book isn't completely up to date. For one thing he no longer recommends amending soil (digging organic matter in). Personally that's not something I've ever done anyway, tried it once or twice and decided I got much better results with deep mulch using paper, cardboard (corrugated, not the slick stuff used for consumer packaging) and all the straw or hay I could lay my hands on. The worms are very nice about coming up and gradually pulling all of that down into the soil, thereby amending it for me.
If you have really heavy clay soil what has worked for me is to plant half the area in buckwheat, mow it down after it sets seed (depending on where you live you might be able to do this up to 3 times a growing season). It will self seed and grow another crop. Then plant something like winter rye to overwinter. Using lots of biodegradable mulch on the side you're planting to veggies and switching back and forth I've had even the worst heavy clay soil improved to a clay loam in 2 to 3 growing seasons with very little actual work on my part. After 3 to 5 years of this you can forget the crop rotation and you'll have a nice crumbly loam full of earthworms. It's the mulch that does it, cools the soil, encourages worms, and worms are natures little soil builders.
Okay, so looking at the brochure on the website, this does interest me. One question that I have is what is the purpose of the the grid on the raised bed? I know I could buy the book and it probably says (and I may buy the book), but I was hoping that some one already knew.
If you go to the web site you can find a short explanation. I think you could find the book at your local public library - that's where I got mine. The grid just marks your planting areas. With the SFG system you plant a different crop in each square foot. The author seems to like the aesthetics of having a permanent grid in place, but it seems to me that in the original book he described a removable grid that was just used at planting time. It's been a long time since I read it, though, so I could be wrong.
Thanks for the explanation. I would think it would be easier to have a removeable grid, so that when you mix stuff into the soil and get through with the harvest, you could mix it all up easier.
I have the weed cloth, so now all I need is the book, the lumber and the soil.
Does anyone know where to get the Vermiculite (this is the COARSE grade, not the fine grade)? On the reviews on the book on Amazon, quite a few people said that they could not find this part of the recipe.
Okay, so I thought I had the lumber issue all worked out. Just so happens that we had a wooden swingset taken down from our yard today. The ends of the wood were rotten, so if can no longer be used as a swingset, but the center of the wood appears okay. Anyway, I was all excited thinking this served my purpose and was reusing something I already have. Great! Well, then it occurred to me (and was confirmed by DH) that the swingset was make of treated lumber, so guess that is out for veggies, right?
I planted my first square foot garden this year!! I have 3- 4x4 beds (2 are multi-level) so far with more in the planning stages. You really should get Mel's book. I got mine on Amazon pretty cheap. The new one is called All New Square Foot Gardening and it has some awesome information. Well worth the price if you buy it. My other go to book is Desert Gardening by George Brookbank - great resource if you are in the Phoenix or Tucson area or another similar desert climate.
On the lumber, I would NOT use the treated wood as it can leach into your soil. OK for ornamentals but not for edibles. You can get Douglas Fir pretty cheap at Home Depot - that's what we used.
As for vermiculite, call any nurseries in your area. I had a tough time finding it even in Phoenix, but did find a couple nurseries that carry the 4 cu ft bags.
[quote]Originally posted by shuggins
Does anyone know where to get the Vermiculite (this is the COARSE grade, not the fine grade)? On the reviews on the book on Amazon, quite a few people said that they could not find this part of the recipe.[/quote]
Cornelius Nurseries on FM1960 (North Houston) has it. Just be aware that SFG Mel's Mix can be very expensive.
Also I find the recommended plant spacing for tomatoes to be optimistic. My plants can get crowded at 2 foot spacing so I am moving to 2 1/2 ft spacing this year.
[quote]For one thing he no longer recommends amending soil (digging organic matter in).[/quote]
All I can say is this is the first time I have ever seen the recommendation to NOT add organic matter every year. I have tasted the difference in flavor of tomatoes compared between a garden with a little organic matter vs. a garden with a ton of organic matter and it's not a subtle one.
feldon...Are you using the mix that is recommended in the book or something else? Could you not use potting soil and amend it with compost? In this case, I assume the raised bed is very much like a container and so you would want soil that is recommended for a container, right? I really know nothing about this and while I do plan to get the book, I also love hear practical advice from people that have done it.
I don't use SFG. My comment was based on the 1/3 Compost, 1/3 Vermiculite, 1/3 Peat Moss. Vermiculite is expensive.
I use my own modified SFG which costs less and so far I'm happy with the results. I start out with Pro-Mix or other peat moss-based product and then add compost, shredded pine bark, etc. This year I have started adding leaves to my garden beds as well.
I understand. Since you are in my area, I was hoping that you might have a mix that wasn't as expensive or hard to find for that matter. I can get to Cornelius, but it is not conveniently located for me. Does Pro-Mix come in a bag or is it a mix that is bought in bulk? Thanks.
Feldon is right. The Mel's Mix can be expensive to make, but it is pretty much a one-time expense. All you need to do after the fact is add a little compost to each square as you replant it. If you compost that cost will be minimal. I did three 4' x 4' beds the first time around. Here in Phoenix the vermiculite runs about $30 for a 4 cu ft bag. It is way more expensive if you buy the materials in the smaller size bags. As 2 of my beds are stacked, I filled anything below 6" with plain old sand (as the book recommends) which is cheap. All in all I spent about $125 for the vermiculite, peat and compost to make my Mel's Mix for 48 sq ft of planting area. Had I had a compost pile already, that figure would have been more like $85 to buy just the peat (3.8 cu ft) and vermiculite (8 cu ft).
P.S. The recommendation for not digging in organic matter applies to amending your NATIVE soil, which used to be his recommendation. With the new method, you DO NOT use your native soil AT ALL in your beds. Thus the Mel's Mix formula.
Pro-Mix is incredibly hard to find in Houston. It used to be $12 for a 4 cu ft block (compressed down to 2.2 cu ft) which was a very good deal for a very finely ground peat moss, etc. An excellent seed starting and potting up mix, and not too bad as a garden bed ingredient.
There are several soil markets in Houston that offer garden, rose, and/or vegetable garden mixes and will deliver or you can pick up in bulk quantities. Some are reasonably affordable as bagged soil as well.
Living Earth is one company that has several locations around Houston. They bought out the local Soil Supermarket near me.
I would fill your beds with some kind of garden mix bought in bulk and then amend it with 2-3 bags of Black Kow ($4.50/bag for 100% rich, odorless cow manure) and/or Sheep Manure, Composted Cotton Burrs, etc. whatever you can find that is clearly of a high quality.
Black Kow is great! My trellis bed was built using compost consisting of leaves, grass clippings, spent coffee grinds, and pureed veggie peels (to attract worms that help with the aeration of the soil). I sifted the compost through a 1/4-1/2" sheet of screen on the bed which had a 6-8 page layer of damp newspapers. This was spread out and left to continue doing its thing (and partly because I miscalculated the Sugar snap pea plantout date...) When I decided to sow some seed in the bed, I folded in a 40 lb bag of BK composted cow manure and one large bag of MG potting mix. The mixture was rich, rich, rich, and loose enough to plunge your hand in up to your forearm.
I sowed turnips, lettuce and carrots in that bed. Here's the before and after pics. Stuff is taking off and will be ready for harvest come mid-April (I sowed seeds rather late, in the first week of November -- next season I'll sow by Sept. 15th...)
Oops. I took pics of the growing bed this Saturday, but they're in the home computer. I'll post the after pics another time
P.S. The respective two small boxes now have Bull's Blood beets and Chioggia Beets growing.
When I say he doesn't recommend amending your soil anymore, I mean he doesn't recommend double digging and digging organic matter into the base soil in your yard anymore.
Like I said, put the good stuff on top and the worms will do that for you. It's a top down approach instead of bottom up and it works MUCH better. Particularly with heavy clay soil - you dig stuff in to heavy clay and it preserves it forever. I know because the one time I tried the double digging and all that, the second year when I dug it up again, everything I'd "dug in" the previous year was still there, looking like I'd dug it in yesterday. There was hardly a worm to be seen.
Green manuring and deep mulch, on the other hand, had that same soil sitting up and begging sweet as you please in nothing flat, worms everywhere.
Gymgirl...do your beds have a bottom? The SFG recommends putting weed cloth on the bottom to keep weeds out. I was wondering if I could put cardboard (thick shipping card board). It would kill the grass, but evidently breakdown enough to allow the worms to get to my beds. If weedcloth is a better idea, I have that too.
I would put the cardboard down now to kill the grass, then if it's not pretty well broken up already when you're ready to plant, take it up and use it on top of your soil mix as the bottom of a layer of mulch. Cardboard can block roots from above as well as weeds from below. Also between now and when you want to start planting, the sod may not have had much time to break down. You may want to break it up some before adding your soil mix and the top layers of mulch.
Mel does some things that strike me as strange and putting weed block down on the bottom of beds is one of those things. Unless you're planting on top of something really pernicious like Johnson grass I don't see any advantage. I've never had a problem in any garden, whether raised beds or not, with weeds as long as I can mulch. I'm all for square foot gardening but I also swear by the value of organic mulches.
When I am putting in a new bed my preference is to kill the grass starting the fall before I intend to plant. You can do this with either heavy duty corrugated cardboard or black plastic mulch. By the time spring rolls around the grass is not only dead, it's fairly well composted as well. People don't always have that option though.
I bought untreated lumber to use for the actual box that will make soil contact. I am considering taking wire and building a frame to go at the back of the bed to let cucumbers or beans climb on. If it doesn't make contact with soil in the raised bed, is there a problem with using treated lumber for the frame for the vines to climb? I am still trying to find a way to recycle some of this swingset. Also, if the treated lumber makes contact on the ground outside of the raised bed, is this a problem?