Because drip systems must be operated at regular intervals, they are almost always automated with controllers. If you have a multi-station controller to turn the irrigation system in your yard on and off, you can use it to control the drip portion of the system, too. Attach your drip system to one of the electric valves that gets its commands from the controller, and set that station to the time and duration you want to water.
If you don’t already have a controller, it’s less expensive and simpler to purchase a simple single-station controller for each drip zone than a multistation controller to control all the zones. These battery-operated controllers are designed to be connected to individual circuits and are usually attached to the faucet at the top of the drip head. Because they are battery-powered, they require no wiring and can be placed anywhere in the yard.
Most have digital or liquid-crystal display clocks that must first be set for the current time, the days that watering is required, and the time and duration of irrigation. Batteries will usually last for a year, and can be changed each spring before use.
Stand-alone controllers are most useful if you have a limited number of circuits — usually no more than three. If you have several circuits you will find it less expensive to install a multistation controller than to add a single-station controller to each circuit. Also, a good deal of mental gymnastics is required to integrate the watering times of several stand-alone controllers without two circuits overlapping.