Is There a Secret Formula to Make Orange Trees Grow Bigger?

Plant the Right Variety for Your Area

• The major U.S. orange-growing areas are California, Arizona, Texas and Florida. Orange varieties that do well in California's Mediterranean climate are the navel orange varieties "Washington," "Cara Cara" with pink flesh and "Lane Late." "Valencia" oranges, a juice variety, and blood oranges also grow well. In Arizona, popular varieties are "Washington," "Hamlin," and for juice, "Valencia" and "Diller." In Texas, "Everhard," "N33E" and "Marrs" are the most common-grown navel oranges, with "Valencia" the most common juice orange. Florida's major varieties are the early "Hamlin," midseason "Pineapple" and late "Valencia." If you want a big orange tree, don't choose one on dwarfing rootstock. Sweet orange trees on non-dwarfing rootstock reach 15 to 20 feet tall.

Plant the Tree Correctly

• Choose a healthy tree with a well-developed root system and a trunk about 1/2 inch in diameter. Favorable planting time is in spring after danger of frost is past and before hot weather sets in. Locate the tree in full sun with enough room to grow to its mature size. Dig a hole in well-draining soil as deep as the root ball and as wide or wider than the roots. The tree's soil level should be the same in the planting hole as it was in the container. Keep the grafted bud union above ground. Back-fill with the dirt that came out of the hole, without adding any extra. Create a 2-foot-wide watering basin with extra soil and water the tree thoroughly.

Give It a Good Start

• Water the newly planted tree every few days for two weeks, then go to every seven to 10 days for two months. Thereafter during the first year, water about every couple of weeks during warm weather. When the tree starts to grow again after planting, sprinkle 1/4 cup of ammonium sulfate over the soil and water it in. Repeat two or three times during the first year. Decrease watering and fertilizing as winter approaches to discourage new growth that is frost-tender.

Pay Attention to the Growing Tree

• Keep the soil under and around the tree free of weeds and grass. Water the tree about every two weeks during the warm months. Don't allow the soil to remain saturated. Apply 2 cups of ammonium sulfate during the second year of growth and 3 cups during the third year. Space applications at intervals during the growing season; commercial orange growers in California apply fertilizer in February, July and September. Usually orange trees don't need pruning, except to remove deadwood or weak branches or suckers from the roots.