In Florida, most oranges bloom in March-April. The "early" varieties, such as Hamlins and Parson Browns, reach maturity in October through January. The "mid-season" varieties such as the Pineapple Orange reach maturity in December-February. "Late season" varieties such as the Valencia matures from March-June.

All citrus , including oranges, must ripen on the tree. Citrus does not ripen once removed from the tree. Grove managers take representative samples of oranges from a particular block of trees, about 40 pieces of fruit for a 40 acre block. The juice is squeezed from the sample fruit and the juice is tested for two main attributes -- brix and acid. From these two attributes, the sugar:acid ratio, which determines the flavor of the juice, is determined. Juice must meet minimum standards in order for it to be sold as 100% Florida Orange Juice.