You can bring in fruit trees right away. One of the nice things about the high desert soils is that they are fairly fertile -- all they are missing is water. If you look at any of the housing developments that spring up in places like Victorville or Las Vegas all the way over to Albuquerque, you see that when properly watered, fruit trees thrive. People move into their new house, stick a tree in the ground, and as long as it gets watered, it's happy. I had a mulberry tree in Las Vegas that had found the underlying aquifer, and it needed no additional
watering, even in the scant 4" of precip that Las Vegas gets. I've noticed that olive trees have no problem in Las Vegas and Barstow, when they get adequately watered. But olives are shallow rooted and can't find that aquifer, so when their watering is interrupted, they shrivel up and die.
If you build your swales and add biochar and
mulch your trees well, they should take off this spring. What you can also be doing now is going out and taking cuttings of fruit trees and rooting them in a protected area. If you don't have a
greenhouse, just put them next to a south-facing wall and baby them a little for the rest of the winter.
Another suggestion would be to plant some prickly pear cactus. Rather than collect wild specimens, you might want to go to a Hispanic market and get your cladodes (planting pieces) there. At least then you will be getting a variety that other people deem both edible and tasty. Prickly pear cactus probably won't need any sort of swale or water catchment, it's the kind of plant that will survive on the natural rainfall, and if you are kind enough to give it a drink once a month, you'll probably be rewarded with a bumper crop.