Freeze damage has the potential to wipe out backyard citrus trees, along with many other types of tree. Though apple, pear and peach trees can survive freezes quite well, citrus trees cannot. One of the most common methods of dealing with freezes and their effect on citrus trees is to use water once temperatures drop below the freezing point. This method is not without its risks, as the weight of the ice accumulation can break branches. Spraying citrus trees is often the only way to protect larger trees.
Test the reach of your sprinklers to ensure that every part of every tree receives water. Add new sprinklers, as needed. If possible, run underground lines to protect hoses from freezing.
Irrigate the land surrounding the fruit tree several days prior to the expected freeze to moisten the soil and trap in heat.
Continuously water the trees throughout freezing temperatures on severe freeze nights. Keep the sprinklers upwind from the tree in case there is a strong wind.
Shut off the sprinklers once the temperature reaches 37 degrees F. If the spraying stops during the freezing period, the heat created by the water through the freezing process will be minimally effective.