Looks like a great area for figs. If you can, get a load of free mulch from the city, or mushroom compost (or whatever free/inexpensive source you can find) and cover the area to prevent weed growth during the winter rains, as well as adding organic matter. Mulch should get a nice earthworm population going too.
Also, get some gopher traps and start killing them. Stainless steel 'Gophenators' are extremely effective and don't rust.
You can keep your trees in 5 gallon containers till they get large enough to put out. Let their roots grow thru the bottoms and into the soil beneath. The plants will be larger and healthier that way, though you will have to clip them when it's time to transplant.