The best orange trees to grow in Louisiana, which is defined on the U.S. Department of Agriculture's Plant Hardiness Zone Map as Zone 8, are sweet oranges (Citrus sinesis). This variety of orange includes clementines, mandarins and satsumas, all of which are small with thin skins. These oranges are easy to peel and are good, but juicy, eating oranges.
Northern Louisiana is in Zone 8a, and temperatures can drop to 10 degrees F. in winter, while southern Louisiana is in Zone 8b, where temperatures can drop to 15 degrees F. All of the state has hot, humid summers, making it good for growing oranges, which require ample heat to produce sugars. Orange trees should be planted in full sun and require regular watering.
Clementine oranges are nearly seedless mandarin oranges that ripen in late fall or early winter. Clementine trees grow to about 20 feet and while they produce fruit annually, these trees tend to have a heavier harvest in alternating years. Trees are self-pollinating and are suitable for most parts of Louisiana.
Clementines are the smallest mandarin orange and the flavor is intense. Originally from North Africa, clementines are most often commercially grown in Spain.
Mandarin orange trees produce a small, somewhat flat orange with bright orange or orange-red loose skin that is easy to peel. The flesh is juicy and sweet, but has pointy seeds that are green inside. The Mandarin orange tree can grow to 25 feet and has slender, thorny branches. Mandarin orange trees may be planted throughout Louisiana.
Considered native to southeast Asia and the Philippines, Mandarin oranges are commercially produced in Japan, southern China, India and the East Indies as well as in the southern U.S. and California.
The Satsuma is an early-ripening mandarin orange that is more cold-hardy than many other orange varieties, and is best suited for north Louisiana. The fruit on this tree is small, loose-skinned and very juicy. The flesh is a medium orange. Though these oranges do not hold well on the tree, they may be stored for a few weeks in a cool area. This tree is fast-growing and can reach 20 feet. It should be planted in full sun and requires ample water. The Satsuma orange originated in Japan.