California's citrus industry is opening its wallets to protect crops as the deep freeze continues.

California's crop of citrus fruits, lemons, limes, oranges, tangerines, mandarins and grapefruit represent nearly $2 billion threatened by this week's record low temperatures.

Farmers are fighting the destructive cold with an arsenal of wind machines, irrigation pumps, tree wraps and smudge pots.

The last line of defense is burning peach pits in the orchards in the hopes of raising temperatures just far enough to hold off freezing.

Over the last five days the California Citrus Mutual in Exeter has estimated growers have burned through $17 million in efforts to keep the crops on the trees protected.

The last time this happened, two years ago, more than $60 million was spent over 28 days in December.