Mac: I think 1.5ft by 3ft would work as well as anything deeper. I'm growing fruit trees in pots 18 inches by 15 inches. My potted trees aren't real big but you will have at least 6 times the soil volume. I think your setup would be good at about 7 by 10ft. Some dwarfing at that spacing would be good. You might not have any appreciable dwarfing depending on how well your trees root outside the bed.

Are you in a flood plain in CA? Is the soil wet right on the surface when there are leaves on the tree? Is the soil sandy or clay? These factors can affect rooting.

Native soil will work if it's not too sandy or too much clay. Pears will be easier than stone fruit.

Citation would be a better rootstock than Nemaguard or Lovell for the peaches/nectarine.

The Fruitnut

I am located i north florida the soil is mostly sand. The soil is wet at ground level. Where can I buy citation from??

Mac: Citation might not be the best in FL. Given that your soil is mostly sand, I'd use that in your beds and go with the standard peach rootstock; whatever your nursery recommends out there. I've got nectarines on seedling peach, Lovell, in my pots and it is working OK. The standard peach rootstocks will work in your beds.

Good luck!!!

The Fruitnut

Hey Mac, if you plant stone fruit use nemagaurd or gaurdian. Sandy soil in the southeast will likely have nematodes and you will need a nematode resistant stock like the two above. Even on raised beds the roots will eventually find there way into the native ground. I think you setup sounds great and I'll bet it will work well foryou.