Central Florida is not only the home of Disney World and many homes, businesses and shopping malls--it remains the heart of the state's orange producing industry. Whether you want to grow one tree or an entire orchard, areas around Orlando, St. Petersburg, Gainesville and other towns are good locales for growing oranges. But late spring frosts, diseases and insects can threaten to decimate your crop.
Winter temperatures rarely drop to freezing in central Florida, but they can---for example, on Jan. 4, 2010 the temperature dipped to a chilly 27 degrees in Orlando, according to the Miami Herald. Although the average winter temperature in Orlando only dips to around 50 degrees F, cold fronts such as this can hit, and they are damaging to citrus of all types. An orange tree can die if it must endure below freezing temperatures for just a few hours, so if you are growing oranges in central Florida, provide protection for the trees on nights with a chilly forecast. Covering your tree with a blanket can help, as can stringing Christmas lights in it or running a sprinkler to keep the tree wet.
Oranges and other citrus trees sometimes fall victim to a fungal disease called powdery mildew. It causes the leaves to develop a white or gray sooty residue and can adversely affect fruit production if allowed to progress. Other fungal diseases can also occur and may be controlled with fungicides. Other diseases that can attack central Florida oranges include viruses, cankers and blight. Keeping your tree healthy and well-fertilized is the best prevention against disease.
Citrus rust mites are a common cause of blemishes on oranges and can be responsible for loss of leaves and fruit falling prematurely. Citrus red mites are another insect pest that can be troublesome in summer because they disfigure the fruit's surface. Scale insects, whiteflies, aphids and mealybugs are also common pests of orange trees. Beneficial insects such as ladybugs can help to keep these pests under control, and there are alternative methods, such as spraying your tree with one quart of insecticidal soap mixed with one tablespoon of canola oil. Fruit flies are almost everywhere in central Florida--check with your local agricultural extension office for suggestions on controlling them through the use of pheromones and other types of traps.