sallyg said: to the site, and gardening
These resting on the ground? I am confused about the dimensions. Are they 10 inches tall? Cold compost, as in fall leaves mostly?
I would fill the rest with topsoil, or local dirt, and plant. The plants will root down in there, I think it'll be fine. In fall you can mix it up some and will have room to add more compost and soil.
But we'll see what others say.
gardenfish said: This is what I would recommend, too. Be sure to put your supports for the tomato plants in place when you plant to avoid damaging the roots later on. This is what I did in my raised bed. Pic below.