Pecan trees thrive in the southern United States; however they are hardy in USDA zones 6 through 9. This deciduous tree is native to North America, and the name "pecan" is actually an American Indian word. It was the Native American Indians and fur traders that brought the pecan nuts from the Mississippi Valley eastward, according to the University of Florida. Pecan trees grow in rich, moist and well-drained soils. It is the state tree of Texas.
The pecan tree is a fast-growing and long-lived tree. Pollination requires two pecan trees. A mature pecan tree can reach a height of from 50 to 70 feet, and a spread of 50 to 60 feet. The grayish brown bark has flat ridges and shallow furrows. The tree flowers in spring, with the fruit ripening in the autumn. The husks of the pecan nuts are brittle and thin, and the pecan nuts have a thin shell. After the nut is released from the husk, the husks generally stay on the tree through the winter season.
Pecan trees require a site that receives full sun. They grow in organically rich, moist and well-drained soil, and they cannot tolerate flooding for an extended period of time. The pecan tree does well in humid climates, and in climates where the summer temperatures average between 75 to 86 degrees Fahrenheit (the winter climate should be moderately cool). Due to their size, trees should be planted/spaced from 50 to 70 feet apart.
The native tree distribution area is from Iowa to Indiana to Alabama, Texas and Mexico, according to the United States Department of Agriculture. The pecan tree is found along river basins: the Mississippi and its tributaries, the Colorado River in Texas, and some of the Colorado River tributaries in Mexico. Most pecan crops are produced in the southeastern United States, with Georgia producing 50 percent of the production.
The water requirements of a pecan tree are extremely important (watering directly affects the amount and quality of nut production). Young trees (1 to 3 years) require 10 to 15 gallons of water at regularly weekly intervals. Pecan trees develop an extensive root system, and deep watering is essential. A mature pecan tree (during the hot summer months) will need 100 to 250 gallons of water per day.
Pecan trees require zinc. Symptoms of zinc deficiency include pale green leaves, dead branches at the top of the tree and bare branches that only have a few leaves at the very tip of the branch. To avoid zinc deficiency and to ensure a good crop of pecans an application of ammonium sulfate is recommended. Ammonium sulfate is a nitrogen fertilizer available at most nurseries or garden centers. Applications can be made in mid-March and mid-May.