Winter season is underway for the San Joaquin Valley, with California citrus growers closely monitoring weather forecasts to prepare for any cold spells that may sweep through the valley in the coming months. 

While cold temperatures benefit the crop by maintaining fruit quality, improving color, and sending trees into dormancy, long periods of below-freezing temperatures are of concern to growers.  

“Cold temperatures aren’t a bad thing for citrus. In fact, they can have positive effects on the fruit and trees," says California Citrus Mutual (CCM) President and CEO Casey Creamer. 

Below-freezing temperatures lasting more than a few hours have the ability to impact all citrus varieties. However, mandarins are often at the greatest risk due to their thin peel.

“It’s when below-freezing temperatures last for long periods of time that we get concerned there could be damage to the crop,” Creamer adds.

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To combat below-freezing temperatures citrus growers run wind machines and irrigation. These techniques help raise grove temperatures and alleviate any negative effects of long cold periods. 

CCM is a voluntary, non-profit trade association whose mission is “to protect and enhance the viability of California’s citrus growers.”

CCM says it will aid growers during the frost season by running the Weather Watch Program. Through this program, the cooperative employs weather stations throughout the region and provides growers with daily citrus-specific forecasts. 

The program runs from Nov. 15 through March 15 each year.