How Smart is Your Sprinkler Controller?

Sep 22, 2014

Help for the Home Gardener from the
Contra Costa Master Gardeners' Help Desk

Client's Question:
I am trying to get good information and advice about water-wise irrigation controllers that operate in conjunction with rain and temperature gauges for my small, mixed-plant residential garden. 

Master Gardeners' Help Desk Response:

Smart Controllers (commonly referred to as ET controllers, weather-based irrigation controllers, smart sprinkler controllers, and water smart irrigation controllers) are a new generation of irrigation controllers that utilize prevailing weather conditions, current and historic evapotranspiration rates, soil moisture levels, and other relevant factors to adapt water applications to meet the actual needs of plants. These controllers will help you to apply the appropriate amount of water in response to your particular plant and soil conditions, often resulting in water conservation. Through optimum water application, overwatering can be avoided, reducing the incidence of soil-borne diseases, and resulting in healthier plants.

Information Sources: While many of the more complex, remote/central controllers are designed for commercial use, there are many which are suitable and affordable for the home landscape. The University of California Center for Landscape and Urban Horticulture website explains the fundamentals of Smart Controllers. This UC site, titled "Is a Smart Controller for You?" might also be of use to you. 

Local Information Sources: Each manufacturer has online information regarding their company's controllers. Most major companies such as Irritrol, Rainbird, Toro, and Hunter make Smart Controllers appropriate for home garden use. While we cannot recommend one manufacturer over another, you might go to a local irrigation supply company or nursery and ask for recommendations which take into account the number of stations and specific needs of your irrigation system.

Rebate Programs: You might also want to check into rebate programs sponsored by the local water districts for installing water conserving irrigation systems and controllers. The East Bay Municipal Utility District has a rebate program for qualifying irrigation controllers. The Contra Costa Water District has a similar rebate program.

Good luck in your quest to find the appropriate controller for your garden! It's great that you are considering a Smart Controller, as water conservation is very important in our Mediterranean climate. Please let us know if you have any additional questions.

Contra Costa Master Gardeners' Help Desk

Editor's Note: The CCMG Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523.  (map) We can also be reached via telephone:  (925) 646-6586, email:, and we are on the web at "Ask a Master Gardener" help tables are also present at many Farmers Markets as well as at the CCMG's "Our Garden" programs (map). See the CCMG web page for details/locations.

By Stephen I Morse
Author - Contra Costa County Master Gardener