The orange tree (Citrus sinensis) thrives in warm climates, growing within U.S. Department of Agriculture plant hardiness zones 9 through 11. These citrus trees are raised commercially for their fruit and juice, and backyard orchardists can grow their own tree for these same benefits. Though orange trees are relatively hardy, gardeners can implement several management strategies to ensure a healthy and bountiful orange tree.
'Valencia' oranges are one of the best types of orange to grow, according to Purdue University, which is why most commercial farms raise 'Valencias.' The variety is known for being juicer and sweeter than most, and has very few, if any, seeds. Additional types of oranges include the drought-tolerant 'Trovita,' the easy-to-peel 'Washington Navel,' and the cold-tolerant 'Hamlin.'
Oranges do best in very deep soil. The deeper the tree's roots can grow, the better it can handle periods of drought, according to Purdue University. Gardeners should breakup the dirt to provide the tree with loose soil to a depth of at least 4 feet.
Orchardists should prune water sprouts immediately to ensure overall tree health and vigorous growth. Otherwise, the sprouts will just drain the tree's energy without producing fruit. Such sprouts can be identified as thin, vertical branches that grow from the orange tree's main branches. Additionally, branches that have died due to pests or weather conditions (e.g. frost) should be trimmed away. To keep the cut portion from stressing the plant, any branch that has a diameter of 1 inch or more should be sealed after cutting with a standard pruning compound.
Once the fruit is picked from the orange tree, it can be stored for up to 90 days if kept at 52 degrees F, according to Purdue University. If the gardener drops this temperature to just 36 degrees F, the fruit can be kept for up to 150 days.
Gardeners growing more than one orange tree should ensure adequate spacing or the trees' growth may be stunted. Each tree should be approximately 10 to 15 feet from its neighbor. If more than one row is being grown, each row should be separated by approximately 20 feet.