Orange trees are small, attractive trees that produce fragrant white flowers in the spring and sweet or sour, nutritious fruit. They are highly popular with home gardeners and can be grown as ornamental trees in containers. In fact, because orange trees are not cold hardy, they are often grown in pots and brought inside when cold weather threatens. Orange trees have simple culture requirements and are rewarding to grow.
Orange trees are warm-weather trees. They grow best in sub-tropical areas such as parts of Florida in the United States, where the temperatures rarely drop below freezing. Extended cold temperatures will quickly ruin the oranges--it only takes an average of four hours of freezing temperatures for ice to form inside of an orange--so if you live in a cold climate, it is best to grow your orange tree in a pot so you can bring it indoors once fall arrives.
If you are planting an orange tree outside, choose a location where it will have plenty of room to grow. There should be 12 foot area around the tree that is clear of other trees, sidewalks or buildings. Orange trees should be planted in loose, loamy soil that is well-draining. The planting site should be exposed to full sunlight, which is defined as eight hours of sun per day. Finally, protect your orange tree from damaging cold winds by planting it in a sheltered, south or southwest-facing location.
Orange trees are planted a bit differently than many other plants. First of all, the top of the tree's root ball should be planted slightly above the surface level of the ground so that water does not collect around the tree's trunk, as this will quickly lead to root rot. The hole should be only as deep and wide as the tree, and it should be backfilled with the removed soil only; no added materials--such as fertilizer--are needed. After backfilling the hole, water thoroughly and tamp down the soil to remove any possible air pockets that could dry out the roots.
Orange trees only need watering once every two or three weeks. The watering should be deep and slow. Watering rings or soaking hoses work well. While mulching is not really necessary, it can help retain the moisture in the ground and prevent weeds from sprouting. If you do mulch, keep a 1-foot area around the orange tree's trunk free of mulch. Do not fertilize orange trees during the first year of life. After that, you can give them 1 cup of nitrogen only for each year of the tree's age. Give one application in February, May, and again in September. Protect your tree from the cold by covering it with a thick blanket. If the tree is too large, wrap the blanket around the trunk or build a soil bank around the tree. Finally, crimp aluminum foil around the trunk of the tree to prevent sprouting and protect it from animals and herbicides.