Answer: I understand your shock. I moved to Phoenix from Southern California 10 years ago. I remember the first time I tried to plunge a shovel in the ground--I had to exchange it for a pick axe!! But take heart. I discovered that once you understand how to improve the soil, you can plant and harvest something year around and grow all kinds of flowers and vegetables. And personally, I haven't found as many disease problems here, perhaps because the dryness isn't as hospitable as a more temperate or humid climate.
You can still plant before the heat, but you might want to consider creating a raised bed for your initial garden. It's usually easier to improve a contained area than a large space. Desert soils have less than 1 percent organic matter, so you need to incorporate a 4- to 6-inch layer of compost into your soil. For soil amendments specific to your area, I suggest you contact the University of Nevada Cooperative Extension office. (Your county agent's ph# is 702-222-3130) They'll have plenty of information (usually free) on a wide variety of topics.
Another good source is the University of Arizona Cooperative Extension, which has an excellent web site at http://ag.arizona.edu/maricopa/garden/
If you decide to plant now, I encourage you to put at least a 2- to 3-inch layer of mulch on your garden to conserve moisture and lower soil temperatures. Good Luck!
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