Of all the North American hickory species, among them the shagbark and mockernut, the pecan tree is the tallest. Pecans can grow to heights of up to 140 feet in their native range, which includes much of the rich soils in the Mississippi Valley. The pecan tree can give your landscape appeal, and when the nuts begin to develop, you can gain the added benefit of their use in cooking or for profit.
Pecan trees have a vase-like shape when they're mature. They have compound leaves, with as many as 17 leaflets, in the range of four to seven inches long, arranged on a central stem that can measure 20 inches in length. Pecan trees have gray bark when young, and it eventually turns to a brown-red color as the tree gets older. Male and female flowers on the same tree mean the pecan’s pollination occurs via the wind blowing the pollen from the male to the female. The popular fruit, a nut enclosed in a green husk that splits when ripe, makes the pecan tree among the most important commercial trees in the United States.
Consider the potential size of the pecan tree when choosing a planting site. Keep the pecan away from structures, and avoid putting it in places with overhead power lines. If planting multiple trees, space them at least 60 feet apart, says the University of Georgia Cooperative Extension website. Pecans require a full dose of sunshine, and during the growing season they need plenty of water to thrive.
Various diseases affect the welfare of a pecan tree. Among them is spot anthracnose, which causes tiny red lesions on the leaves, resulting in holes. Pecan scab can hurt the overall production of the nuts. Different fungi may cause rotting in the heartwood of a pecan, while the roots are susceptible to root rot ailments.
Several kinds of insects will gladly feed on the nuts, wood, leaves and twigs of a pecan tree. Beetles such as the hickory borer produce larvae that damage the tree trunks. The larvae of the hickory bark beetle will chew into the trunk and branches, weakening the tree and making it vulnerable to other diseases. Pinhole borers, flat oak borers, the hickory shoot curculio and the flatfooted ambrosia beetle all cause injury to a pecan.
There are many hybrids of the pecan to opt for when choosing this kind of tree for planting. One is the Excel, a cultivar that produces large nuts. The Elliot features smaller nuts shaped like teardrops, while the Gloria Grande, a tree that takes many years to produce a crop of nuts, will yield large numbers when it does come of nut-bearing age. The Amling hybrid, developed in Alabama, is a low-maintenance tree with high quality nuts.