A major benefit of an irrigation system is that you can set up different watering zones in your yard. These zones are then programmed into the irrigation control board so you can adjust the watering amount and timing by individual zone. Not only can this save water, but it also ensures your plants receive exactly the amount of irrigation they need.
Division 1: Plant Type
Every plant has different watering needs, so the first step when designing your irrigation system is to divide your yard by plant types. The initial zones should be divided by lawn and turf areas, perennial flower beds, and tree and shrub plantings. If you have plants in these initial zones that are the same type but with very different water needs, full subdivide these into different zones. For example, your drought-tolerant yuccas in the front yard should be in a different zone than the more water-hungry hostas along the back fence -- even though these plants are both mid-height and shrubby.
Division 2: Sun and Rain Exposure
Once you have your large plant type zones, further divide these by sun and rain exposure. Areas of the lawn that are exposed to the heat of the sun all day will require a different watering schedule than the same lawn grass in a shadier, moister area. There may also be areas that tend to get more water when it rains, such as those near drainage basins, so these zones may also require less watering. Although there will be seasonal differences in sun and rain exposure, try to divide these zones in a way that makes sense for the bulk of the irrigation season.
Division 3: Frequency
The final division you need to make to dial in your watering zones is how frequently an area needs to be watered as well as how the area is used. Areas with heavy foot traffic may need more frequent watering or longer watering times so that moisture can better penetrate the compacted soil. Parts of the yard that dry slowly may only need infrequent watering so they don't become boggy. You may also want to consider installed automatic moisture meters in areas that require infrequent watering. These meters track the moisture level in the soil. When it falls beneath a preset level, it triggers the sprinklers to run in that zone. You can use a meter for each zone in your yard or only for those that would benefit most.
Contact an irrigation service, like Pacific Sunscapes, if you need further help in setting up the zones for your watering system.