Mark Twain famously advised, "Buy land, they're not making it anymore."
If you'll forgive my mangling Mr. Clemens' aphorism, allow me to alter that advice: "Don't buy soil, there's no need to make any more." Or something to that effect.
That doesn't quite work, does it? Never mind.
On to business:
One of the most common themes I hear when talking to people about starting a vegetable garden is the need to "buy soil." I'm frequently asked what kind of soil is best to buy, or what kind of soil is best to buy for a raised garden, or, most distressingly: "I've dug all the soil out of my garden area and thrown it away; what should I buy to replace it with?"
Frequently, the upshot of the assumption that soil is a commodity is the decision that one can't possibly plant a garden until one can "afford" soil, or until one's husband finishes building the raised beds, or until the nursery re-stocks a particular brand of vermiculite, or until one finds a better "soil recipe" than the one used last season. This is nonsense. With a very few exceptions, if you have a plot of land, you have all the soil you need.
What you need, because this is the desert, is to improve the soil you already have, and that is very simple indeed. Select your garden spot and clear it of grass and weeds. Layer on top of your existing native soil a good 5 to 6 inches of organic amendment such as compost, or a combination of compost and manure. Using your spading fork, turn that layer into your existing soil to a depth of 10 to 12 inches. Rake it out, break up the large clods, and you're ready to go.
Do you now have perfect garden soil? No.
Good garden soil is not something you can buy, nor is it something you can achieve instantly. Good garden soil develops over time and there are no shortcuts.
Each season, as you prepare for the next planting, repeat the process: layer, dig, rake, plant. In the Desert Garden, with our multiple growing seasons, you can amend your soil three times a year.
Start now, and by this time next year, you'll have very good garden soil; by this time the following year, you can modestly call it "almost perfect."