Tucson’s average date of the first frost is Nov. 28th. Not all citrus tree varieties are equally cold hardy. Sweet and navel oranges, tangerines, tangelos, and grapefruit trees can tolerate lows down to 25ºF without significant damage. Lemon, lime and citron trees are more sensitive and will suffer some damage below 29ºF. So when frost is in the forecast, here’s what you can do:
COVER THE TREE
For smaller trees, create a shelter using wooden stakes and drape with blankets or a burlap sack. This will help conserve the heat accumulated during the day from the sun. Make sure none of the covering is touching the leaves of the tree because this can cause them to freeze.
PROVIDE AN ADDITIONAL HEAT SOURCE
Old-fashioned Christmas lights (not LED) or a 100-watt lamp (designed for outdoor use) with an incandescent bulb can be a great heat source. Place them in the canopy of smaller or medium-sized trees that have been covered. Be careful to ensure lights don’t come in contact with water, and that they don’t get too hot under the covering.
MAINTAIN SOIL MOISTURE AND REMOVE MULCH
Water-stressed trees are more likely to get frost damage. Be sure to check the soil and provide adequate water around the base of the tree. Moist soil also holds in more heat throughout the night. Removing mulch during winter also allows more heat to be absorbed from the sun that can radiate back to the tree at night.
It’s important to temporarily remove the tree’s covering during sunny weather so that excess heat does not build up inside the shelter.
WHAT SHOULD I DO IF THERE IS DAMAGE TO MY CITRUS TREE?
In the event that your citrus tree does get frost damage, the best thing to do is wait until the spring for pruning. When new leaves begin to grow it is much easier to determine which branches are dead. This also allows the tree more time to try and recover from damage.
Of course you can always contact us at anytime to evaluate your tree and provide a free estimate.