180,000 acres of the Central Valley are covered with it. $2 billion dollars a year is made from it.
Freezing temperatures can give a citrus farmer the chills. Overnight temperatures in the Valley are expected to be some of the coldest of the season.
Depending on the type of Orange, below freezing temperatures can destroy a crop. Using irrigation and heating fans can save the fruit, but each fan costs about $30 per hour to run.
With over 16,000 of those fans running in the valley, the cost balloons to over half a million dollars an hour.
Valley groves are stocking up on peach pits. They're considered a "last resort" for when temperatures fall way below freezing.
Still, citrus growers might say they got off easy this year. 2011 had about twice as many frost nights than this season to date.