Orange trees (Citrus sinensis) are indigenous to northeastern India but develop worldwide in regions with the ideal climate and conditions. Growing oranges gives you your own tree-ripened fruit at little if any cost. Orange trees are reliably hardy and do well in U.S. Department of Agriculture plant hardness zones 9 through 11.
Orange trees are climate-sensitive plants which have quite definite temperature conditions. When they are actively growing, they do best if temperatures range from 55 to 100 degrees Fahrenheit. They become dormant in winter and require temperatures no lower the 35 F or higher than 50 F during this period. Orange trees can also be extremely frost-sensitive, although some varieties can survive short periods at temperatures at or below 25 F. You can minimize frightening of your tree if you live in a cool place by putting it in the warmest portion of your landscape, such as near the south side of a building.
Oranges trees do best in regions that have 40 to 45 inches of rainfall yearly, but can endure up to 60 inches of rainfall if they are in places which don’t remain saturated for extended periods of time. They generally endure drought quite well and can produce more intense color in the peels of the fruit when grown under partially dry states. But soil that is dry for extended periods can reduce the number and magnitude of a tree’s fruit.
Orange trees prefer sandy soil, especially of a type known as high lens or high pineland soil that drains well and does not hold water for any period of time. They also need good soil depth to adapt their extensive root systems, doing poorly in regions where soil is shallow and sits on rocks or gravel. Ideally, the water table in a planting area ought to be more than 30 inches below the surface for the best root growth and tree vigor.
Sun and Nutrition
Orange trees make the very fruit when grown in full sun, although they can tolerate partial shade. They do quite well in locations that have lightly filtered shade, such as in shade produced by neighboring tall trees, including pines or oaks. Since they’re generally strong divers, orange trees need regular fertilizing, requiring about 1 cup of high-nitrogen formulation for every year of tree age, implemented three times every year, in February, May and September.