Now here's the problem. I am trying to decide whether I should frame these beds using 2" x 10" x 12" planks or 2" x 12" x 12". I am also concerned about the underlying soil. All the soil underneath the sod appears to be SOLID CLAY!
I have a roto-tiller. I used the rototiller with my first 2 beds, but I am not so sure that was the right approach. Double digging appears to be out of the question since I would be lifting lots of clay. My soil appears to be all "subsurface."
I am going to have 2 cubic yards of topsoil / humus delivered next week after I made the wooden frames. My current beds don't have very fine crumbly soil due to high clay content even though I have went through a lot of effort to amend with organic materials. I have only had the beds a year now.
Should I leave the subsoil as is and put the new top soil over it? Should I loosen the clay subsoil with a pitch fork?
Any suggestions on how to handle this situation would be greatly appreciated. I know people on this forum definitely have the experience to handle this question.
I HATE CLAY! Our city has a very clay-like soil. Mich more than my old neighborhood I moved from.
Chris

As for the boards themselves, the THICKER, the better. Go for the bigger boards -- you're going to have a lot of pressure exerted from the inside of the box outward when your dirt settles in; you want them to hold up for years to come. I think we used the 2" wide boards and now ours are beginning to bow out at the seams and not look very pretty. You might even want to double-up your side boards (I would do that if I could do it over again). Make sure to reinforce your seams/corners, too.

Also keep in mind (if you're doing vegetables) to rotate your crops every year or so -- and keep supplementing the soil every spring with new organic matter. Being in such a confined growing space (and not being able to root into the underlying subsoil to gather additional nutrition) causes your plants to suck out ALL the nutrients in the boxes. We had a "blossom-end rot" epidemic one year with tomatoes -- live and learn. How was I to know the previous year's tomatoes had leeched out all calcium in the soil and my next year's tomatoes were suffering?

Anyway -- have fun and good luck!!

Here's what we did to deal with the clay:

Year 1: Rototill beds and dig out any offending plant roots (you'd be surprised how much of this you'll have to do, especially if you have lots of trees or shrubs). Till in several bags of Clay Buster (a soil amendment you can get at most garden centers) and/or peat moss or pulverized pine bark (clay is also highly alkaline - ours tested out at pH 8.0 in places!) Add a 2" layer of composted manure on top of that and tamp down; mulch after planting. In fall, remove or till in dead plants and mulch. Add as many fallen leaves as you can rake up to beds.

Year 2: Your bed should be double-diggable by this point, so you can avoid the Rototiller. Add several more bags of peat moss or pulverized pine bark (both are good soil looseners) and dig that in. Add more compost on top of that. Plant, mulch, add leaves and dig under in fall.

Year 3: You'll probably want to pH test your soil before adding anything more acidic (unless you absolutely must have blue hydrangeas or other acid lovers). Otherwise, same procedure as the first and second years.

Year 4: Don't do a lot of spring digging in this year unless you have to, as you're looking to build soil structure now. Just add a thick layer of compost to the top and tamp it down. Plant, mulch, dig under in fall.

Year 5: Done! You'll want to add compost or your choice of organic matter yearly to maintain the beds, and of course, mulch is your friend!

Hope this helps!

I filled the boxes with as much compost as I had, as well as a topsoil, compost mix from the local garden center. At the end of the first season I collected as many leaves as I could (the neighbors first met me stealing thier leaf bags). I ran over them with the mulching mower and dug them into the beds, finally going about 1 foot above the level of the beds in the middle. I covered with landscape fabric and turned as weather allowed.

Year two I turned the beds, planted and mulched with extra finely mowed leaves I had left over. I repeated the process I did last fall and winter.

Year three, I tuned the beds, took half the soil out of one bed and replaced about 1/3 with sand (for herbs, I wanted better drainage in that bed).

My soil has not been walked on since year 1, the soil is amazing, looks & smells great (my 15 month old son even likes eating it??)

CMPman I noticed that some of the things in your want list are available locally (in roseville)

~Chills