Sweet orange trees (Citrus sinensis) come in different varieties with different shapes, heights and widths. The age of a tree and the specific climate where it grows also affect whether or not the tree will grow as tall and as wide as it can. All oranges need full sun, moderate to high heat during the growing season outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11, regular water and protection from hard frosts to produce at their best.
Generally speaking, sweet oranges grow to about 25 to 30 feet tall. The trees come in rounded globe, umbrella and vase shapes, with most reaching from 20 to 30 feet wide. Valencia types (Citrus sinensis "Valencia"), the orange used for commercial orange juice, and Arizona sweets, such as "Diller" (Citrus sinensis "Diller"), grow somewhat wider than navel varieties, such as "Washington" (Citrus sinensis "Washington").
Most dwarf oranges grow from rootstocks of mandarin oranges (Citrus reticulata), also called satsumas or tangerines, which grow in USDA zones 8B through 11. Naval, Valencia and Arizona sweets varieties all come in dwarf varieties, ranging from 8 to 12 feet tall and wide, with Valencias generally reaching both taller and wider than navels.
While they don't meet precise measurements, semidwarf-size orange trees occur naturally as somewhat smaller in height and width than standard trees and larger than grafted dwarf ones, ranging from 10 to 20 feet tall and wide. Semidwarf varieties include "Marrs" (Citrus sinensis "Marrs"), a variety of Arizona sweets, and "Fairchild" (Citrus reticulata "Fairchild" ), a mandarin variety.
Sour Oranges and Mandarins
Like sweet oranges, sour oranges (Citrus aurantium) and mandarin oranges (Citrus reticulata) need lots of sunlight and regular water. Like sweet oranges, sour oranges grow in USDA zones 9 through 11. Sour orange varieties grow about 20 feet in height and width, while mandarins range from dwarfs that reach 5 to 10 feet tall and wide to standard varieties reaching from 12 to 20 feet in height and width.