I have a raised bed (shipping crate) that's about 24" deep on my driveway. I haven't had any problems. If you are selective, 8" of dirt should be enough.

Thanks ljpother.

I'm going out right now to prepare it =:)

Just speculating, but it might get hot from the concrete and dry out really fast. Also, my garden box even though it's 2' deep is nicely populated with worms. You might not get worms to stay in that even if you add them. Besides that, I don't see the difference from any other container gardening. If it doesn't go well it would be easy to move.

I was wondering, too, Northspruce, about the heat. I had placed the frame on the lawn where I planned to have it, but got the heebie jeebies thinking about the voles that were probably within a few feet of me. Bleck!!

I don't think worms would stay either, but I will have worm castings and I could throw a bit of that on, if I want to. I have no idea if it's good or bad to add worms castings to potting type soil instead of real dirt. I'm not sure how DH will feel if I "waste" the worm castings he put so much work into making. In a 4x4 area I can experiment without it being much of a loss. ljpother's setup is 24". I wonder if I should make mine deeper? It wouldn't take much to put another 6" onto mine if I decide to.

Northspruce - What is your "garden box"?

BTW I realize a frame is like a container, but do I "have to" put potting soil into it? Would topsoil and peat moss be a bad thing to do? ljpother, if you're here, what's in yours?

nutsaboutflowers,

Go for it. I use PC topsoil ("black earth") in my containers and personally don't see any difference compared to potting soil. Way cheaper too. It is a bit weedy but that's not a problem for a few containers or raised beds. As long as you stick to sterile potting mixes for seed starting, you'll be fine.

Instead of preventing it getting hot, use it to your advantage, say, for growing peppers. 8" is not optimum but certainly enough for many plants.

Hey, drhorticulture, haven't "seen" you for a while.

I think since it's only 4x4, I will go for it and just fill it with whatever I already have, or whatever the first store I see has in stock.

I want to get some lettuce, arugula, and peas planted, so I better just get to it =:)

My garden box is 8'x4' and three 2x6s high so it's more like a foot & a half deep. It's on lawn though so the bottom isn't enclosed. I dug it over this spring and there were lots of worms. :) I filled mine with Home Depot cheap topsoil plus two composters full of half-finished compost and a couple of bags of composted manure. I wanted to build another one this spring but HD didn't get enough topsoil and they sold out in 50 minutes, so I don't know if I'll fill it with something else or just not get around to it this year.

The one on the driveway has some Styrofoam in the bottom to take up space. I won't do that again. The rest is basically a lasagna bed with a thin layer of soil on top to plant in. Last year I planted in strips of ProMix. I ran out of compost to mix with garden soil. And that's why I won't waste space with styrofoam again. I use the deep raised beds to make compost.

Hey, I guess I should be calling mine a garden box, too =:) I have two of them but one's full of strawberries. DH tells me they're made with 2 - 2x6's, but I could have sworn they're not that high. Maybe I can convince him to add another 2x6 to the top.

Both of you compost. I didn't know that. Do either of you get hot compost? I don't bother stirring or watering or anything. I just bury stuff a few inches down each time to keep stuff covered. However, I've only got a small amount left, as I used a lot of it last year.

I wonder if there's voles in it........if there is, I don't want to know. I don't think I'll feed my compost pile this year. The worm castings will have to do for now. Maybe I should get DH to make me some vermicompost tea. Have either of you ever made compost tea with your compost?

I digress =:D

I am the most dedicated bad compost maker ever. The only compost I have ever finished was a black bag of leaves that ended up under some brush for 4 years and when I cleaned it up it was beautiful rich black soil and teeming with shiny black ants. All the compost I have made since then has ended up half finished as the first layer of a garden box. Works fine for me & my worm friends.

I don't hot compost. I have three raised beds, a green cone, and a mesh cylinder. I try to mix one with browns, greens, etc.. The others are just piles of leaves and stems that become part of the good mix eventually.