Hi, This is my first year doing a square foot garden. I just made two beds each 4x8x10inches deep. I didn't have to stack lumber. I filled them with "Mel's Mix" (1/3 peat, 1/3 compost, 1/3 vermiculite). It is the most wonderful soil I have ever seen! Mel's book says you only need 6 inches, I wanted 10 so I could grow carrots. I did have to buy all my compost because I haven't started a compost pile yet. The "dirt" for just one bed cost me about $125.00. One of your beds would be almost double that. I could definately see how 18 inches would be nice. You would not have to bend down as far, you could even put a cap on top and have a "bench" like area. Which ever depth you choose, I'm sure you will have a wonderful garden this year. Good luck

Sheila

Howdy, Gryph!

My first year, all I had was the book. I amended genuine Texas clay (much like Georgia clay, but stacked in 4 contrasting layers of color....) My "soil test" (pickle jar of sample dirt and water, shake and leave to settle) showed a layer of clay with a few scraps of dried grass and leaf floating on the surface. 99.9% pure clay.... I found 1 solitary earthworm in 5 years of digging around an acre, and never hit bottom, even digging 3 or 4 feet down.

Now here's the GOOD part. My amended soil (about 1/2 clay, 1/2 goodies) was Terrific! It was almost as good as modern Mel's mix. Many varieties of crops grew big, sweet and healthy with very little care. In fact, I just mounded the stuff up off the "walkways" to form 8-inch beds. The sun baked the edges hard very quickly, and the beds kept dozens of peppers and tomatoes growing and producing through December without cover (Zone 8a, 3 multiple-day hard freezes).

Clay, properly amended with compost and aged manure, can be excellent gardening soil. If money is an issue for very deep beds, that might be a workable solution.

However, I personally would rather use a low gardener's seat and shorter beds, as long as I had more mobility than a wheelchair. (A cinderblock makes a pretty good gardening stool if you are strong enough to move it, so that give you dimensions to aim for.)

You don't have to worry about the mix sitting on clay soil. As time passes, that foundation soil will improve very nicely. That's why you can just lay down a frame and fill it.

(If you even imagine you could attract rodents, you might staple hardware cloth to the base of your frames before you lay them down. Not dirt cheap, but it will give lasting peace of mind.)

Enjoy those wonderful beds!

I was wondering the same thing, but i want to make very short beds. I'm thinking of using 2X4s on tops of tilled soil, beds 4'X10'X4". I'll fill the beds with a mix similar to mel's mix, and I'll incorporate it with the existing soil below the beds. I originally planned to use 2X6 boards, but each bed would take .75 yards of "soil" to fill, making it cost much more than I would like for each bed. Doing them only 4" high will make it take only .5 yards of "soil" so it will be cheaper, but do you think things will grow as well as if I put the extra 2" in??

Thank you in advance for your help and expertise.

Jessica

I am glad so many people are interested in raised beds. The depth needed depends mostly on what you are planting. Mine are 12 inches that are only filled to about 10 with soil. I too have clay soil that is nearly waterproof. My worm count was low as well, so I went to the bait store and bought a bunch of red worms and dumped them in each bed.

I read about the soil mix, but found it to be quite pricey. I went with a screened topsoil from our local landscaping store. I got it in bulk and had it delivered,so it was fairly inexpensive. I added peat moss and some mulch and the beds have been very productive. Just remeber that the plants can get into the soil under the beds should they need to.

I currently have 2-4 by 16 foot beds and 2-3 by 16 foot beds as well as a 4 by 12 foot bed full of strawberries. They are all so much easier to weed.

Hi Guys!

Raised beds are an excellent idea!

My beds are only 8-10" and they seem to do quite well.

I believe a large part of successful gardening is the soil mix and the fertilizing techniques the gardener uses. SQG
has many ideas that will give the gardener ample opportunity to be the best at harvesting a good crop in minimal space.

Happy Springtime,
Psalty

To help me plan the depth of my boxesI need some basic help.
I would like to know how much of the three componets I need for a 4X4 bed...6-8inches deep.
Sure 1/3 of each is great but how much of each... lets say in pounds to fill the 4X4 bed????

Just a little math really:
4 X 4 =16 sq ft of surface area X .5 fo half a foot deep = 8 cubuc feet. We will say 9 to make it real easy. 9cu ft devided by 3 =3 cu ft of each in the mix. Garden soil amendments are commonly sold in cubic feet. Ya need 3 cu ft of each.

I only have one bed right now, it is 24 inches deep. I have very bad knees and didn't want to have any problems in the future. Future beds are only going to be 18inches as I now realize that 24 was a tad ambitious, but it sure makes working in it a dream! I have a 6 inch bench going around the whole bed and it makes things even easier. We will see how much fun it is though when I try to harvest indeterminate tomatoes this summer!

Over sand on a hillside, I've established I can "get by" with 4" of compost over cardboard and then the existing soil. Over clay, I'd go with 1' of mix/compost, minimum

I also just established that buried soaker hoses last 3-4 years and am looking at drip systems and usig alternate watering methods until I get that in place.