An irrigation timer is a device that controls when a watering system turns on and off. It ranges in design from a simple unit that can be used by the home gardener to complicated automated systems used by professional landscapers and farmers. The three basic types of irrigation timers include mechanical timers, battery powered timers, and electric timers. Depending upon the type chosen, an irrigation timer may include a variety of convenient features to suit a range of irrigation needs.
A mechanical timer is the simplest and least expensive kind of irrigation timer. It doesn't require power or batteries and attaches to a garden hose or tap. It works like a kitchen timer, so a user turns the water on manually and the timer shuts it off based on a pre-designated time or volume of water used. It is usually set by rotating geared wheels, and is very reliable because it doesn't need external power.
As its name indicates, a battery powered timer runs on a battery that generally lasts for a full season. It also attaches to a garden hose or tap and has both automatic on and off features, so users can schedule when watering should begin. Some models feature LED screens and can handle multiple programs, making them a popular and convenient choice for vacationing gardeners. If the battery dies, however, these timers will usually lose their programming.
An electric or electronic timer can be complicated and more expensive, but it usually has significantly more functionality. It connects to the main water supply and runs on external power, often with a backup battery. Depending upon the model, an electronic irrigation timer may be able to control multiple valves, allowing users to schedule different times and programs for each valve independently. It usually has a key pad and an LED display screen for programming. Users can designate a start time and the duration for which the system should run, and can schedule supplemental watering or bypass watering altogether with additional features.
For more complicated irrigation systems, an irrigation timer with more features may be beneficial. Timers can be purchased with sophisticated options that include multiple programs, multiple start times per valve, and the ability to make system-wide changes to watering times and frequency. Some even come equipped with weather sensors to detect wind, rain, and moisture, and can make irrigation adjustments accordingly. Many of these timers can be operated by remote control or from a computer through a telephone line.