South Central Florida is categorized as zone 10 in the USDA hardiness map, with the upper portion reaching into zone 9b. Most citrus trees grow well in all areas of South Florida. Orange trees are low-branching, medium-sized trees that can grow to 50 feet tall, but they are usually grown to heights of only 15 or 20 feet. Citrus prefers growing in full sun on nutrient-rich, well-drained soil. Florida citrus is divided into three seasonal categories.
Early-season sweet oranges are harvested from October through January. Cultivars include Hamlin, Parson Brown, and navel. Hamlin oranges tolerate cold well and have high yield of fruit with zero to six seeds per fruit. Parson Brown, slightly earlier to harvest than Hamlin, is seedless and produces less fruit than Hamlin. Parson Brown has zero to thirty seeds per fruit. Navel oranges peel and section easily and have zero to six seeds per fruit. Premature fruit drop is often a problem of navel oranges due to yellowing and rot of the small secondary fruit embedded at the blossom end--a characteristic of navels different from other early-season oranges.
Mid-season oranges are harvested from December to February or March. Pineapple orange is a good mid-season cultivar, but it is the least cold-hardy of mid-season oranges. Sunstar orange is more cold-hardy than Pineapple orange and has fewer instances of pre-harvest fruit drop. Midsweet and Gardner oranges are harvested January through March and are cold-hardier than Pineapple orange.
Valencia is a late-season orange that is harvested from March to June. Valencia orange trees carry two crops at the same time--oranges from the current growing season and oranges from the previous season that take approximately 15 months to reach maturity. According to University of Florida Extension literature, Valencia is the most important sweet orange variety. It has excellent fruit and juice quality. Valencia oranges have zero to six seeds per fruit. A recommended variety is Rhode Red.