Ask ten different landscapers how they would install a single irrigation system and you'll get ten different answers. So how is anyone supposed to know how to set up what is essentially, in the desert Southwest, the lifeblood of a landscape? Though it's probably easier to explain what not to do, the following is my number one tip to get you on your way to irrigation mastery.
Needless to say, an irrigation system in Tucson, Arizona is a completely different animal than one installed, say in the Midwest. Overhead watering, for anything other than lawns, is not a great idea. Dividing a system into spatial zones (e.g.: front yard, backyard, etc.) also creates problems. And differing plant types sharing the same watering system is wasteful and ill-advised (adjusting just the pressure compensating emitters only accounts for one of the necessary variables). The best way, I’ve found, to organize an irrigation system is to consider each type of plant being watered - a.k.a.: hydrozones.
Trees. Shrubs. Cacti and succulents. A vegetable/herb garden. Potted plants. Citrus. Each category of plant material has very distinct water requirements. For example, trees will benefit from deep, infrequent watering while potted plants will want short bursts of moisture multiple times each day. This means that a separate valve assembly (including filter and pressure regulation) will be required for each plant grouping. Weekend Warriors can set this up themselves, though a licensed landscape or irrigation contractor is the safest bet. It’s really not that expensive an endeavor once the benefits come into focus. Just a little extra investment up front pays off in the end.