Irrigation Zone Addition and Expansion

When a new zone beats adding heads

The tempting fix for a new bed is to tee into the nearest line. That works until the station has more outlets than the supply can feed, the far heads lose reach, and the old plants and the new ones are forced onto one schedule. New plantings need water far more often than established ones while their roots grow; the Arizona Municipal Water Users Association gives establishment periods of about a year for shrubs and about three for trees. A separate zone lets the new planting run on its own schedule, then be stepped back as it settles, without changing what the rest of the yard receives.

The same reasoning applies when one station mixes very different plants, such as turf and shrubs, or sun and deep shade. Splitting it is often the real repair.

On a Sun City lot the new bed is often a citrus or shade tree. University of Arizona Extension notes that cold air settles into the lowest spot, so a frost-tender planting at the low corner of a lake or fairway lot may deserve its own zone.