Orange trees are citrus trees that are best suited for climates in which temperatures stay above freezing year-round. Except for miniature varieties, orange trees typically grow to be 22 feet to 30 feet tall. To keep your tree healthy and reap the benefits of delicious oranges, you will need to take good care of it.
Fertilize your orange tree, starting in the spring. Your orange tree needs common fertilizer nutrients, which are nitrogen, phosphorus and potassium. It also needs other nutrients such as copper, zinc and magnesium. Look for a fertilizer that is labeled specifically for citrus trees. Choose a slow-release option, if possible. Because each fertilizer has different strengths and release rates, follow manufacturer directions for dosing amounts and application frequency.
Keep your orange tree warm if you live where temperatures drop below freezing. If possible, take potted orange trees indoors before the first freeze. If your tree is not in a pot and young, bank 15 inches of clean soil up along the trunk. Alternatively, wrap the trunk with a tree wrap, or do both for extra protection. If your tree is not young, but still small enough, cover the tree with a tree blanket. Do this for up to three days. Afterward, take the blanket off during the day to give the tree much-needed sunlight. Add a small heater or lights underneath to add heat for extremely frigid temperatures.
Prune your orange tree. Prune away damage limbs. Also prune water sprouts--also called suckers--which are limbs that shoot up from the ground that take or suck up the tree’s much needed water and nutrients.
Take care of any diseases. Orange trees are susceptible to diseases such as citrus canker, sooty mold, greasy spots and root rot. If you notice yellow scabs on the leaves (citrus canker), black leaves (sooty mold), yellowish brown blisters (greasy spots) or brown patches on the trunk (root rot), you will need to immediately treat your tree. Treatments include fungicide sprays for the specific disease and the removal of affected limbs.
Take care of insects. Aphids, citrus whiteflies, and orange dog caterpillars, just to name a few, are some of the insects that eat or suck the sap out of the leaves. To treat, use an insecticide specifically for citrus trees and be sure to get the top and underside of the leaves.