Low temperatures can cause serious injury to leaf, wood, and fruits of fruit trees. An extended freeze can kill a citrus tree. A rapid temperature decrease or a longer duration of freezing temperature can worsen the damage.
Because preparation is paramount in protecting citrus trees, growers should use the Florida Automated Weather Network. The network provides information that can help growers determine if a freeze is coming and how to prepare for it with cultural practices like the use of micro-sprinkler irrigation. Micro-sprinkler irrigation works by providing heat from the warmth of the irrigation water.
Citrus trees may withstand low temperatures if they were hardened properly before freezing. Fortunately, damaged citrus trees can recover from freezing. However, there are various factors — such as time of year, condition of injured trees, and weather conditions after freezing — that need to be considered when choosing a recovery approach for freeze-damaged trees.
Because it is very difficult to assess the damage right after freezing, it is recommended to wait until the spring when the flush is fully expanded and mature. Branches and twigs may continue to die for several months following freeze damage. Therefore, pruning should be avoided until new growth begins and fully develops late in the spring or in the summer.
Until the trees recover to their original canopy size, the fertilizer rate should be reduced but applied more frequently based on the amount of tree damage. Because leaves are one of the most susceptible parts of the tree, freeze-damaged trees will lose their leaves. Because of that, transpiration will be greatly reduced. Therefore, trees will need less water. Excessive water supplied to the trees should be reduced, otherwise, it will result in root damage and nutrient movement below the root zone. Accordingly, due to less transpiration, the amount of water required should be reduced. Weed control is important after freeze damage due to competition between weeds and trees for water, nutrients, and light. Fungicide application is also recommended to control greasy spots in May and July.