Well, I decided I had to make some greater allowance for moving around the beds. I kind of forgot there would be a wall of chicken wire all around the edge... So the paths around the outside edges will be 2' wide and the inner ones more like 20". That's enough to get around.
So... I took the first big step and went to the Home Depot to buy twelve 2"x8"x8' boards. A few years ago, they wouldn't cut pressure-treated boards, but now they do. So I selected 12 decent boards (had to look at 20 boards to find 12 straight ones) and had them cut 8 of them 7' long and 4 of them in half.
That gives me enough boards to make two 7'x4' beds two 8' boards high.
Here's the plan... I have enough space cleared of the old rotting beds to build the 2 new beds. I can then move the soil from the existing old beds to fill the new 2. Then I can knock apart 2 more old ones and build 2 new ones, etc.
Why not just rebuild all the old beds you ask? Well, the paths between them were too wide (wasting space) and they faced the wrong direction. When you have limited sunlight, that matters. And odd as it may seem, six 7'x4' beds with narrower paths give me more gardening space than the four 8'x3' beds in the same area.
Trust me on this...
So over the next couple days I'll dig a shallow trench to set the new frames in level (a flaw to correct about the old beds which were more unlevel than you would think sitting on what looks like flat ground) and construct them more sturdier (sturdily?) And I will be adding compost to the new beds, which should get them off to a good start next Spring. And the new beds will be higher, so there will be more decent soil for roots to grow.
It's a lot of work, but it will be worth it. especially since I will be able to cover 1 bed each year with black plastic to kill the weeds and nematodes and such. Sometimes half the battle to grow good crops is to manage the soil. Healthy soil means healthy crops.
I'll take pictures as I go.