The pecan tree can grow to massive sizes under the right conditions, and the tree is an important species in the United States and elsewhere in regard to the tasty nuts it produces. The University of Florida's Institute of Food and Agricultural Sciences website states the pecan comes from the same family of trees as the black walnut and the hickories. Pecan trees grow slowly and take some time before producing their crop of nuts, but make excellent shade and landscaping trees for places where they have the room to grow.
The Floridata website says that some pecan trees under perfect conditions can grow to heights of about 180 feet, with a 7-foot in diameter trunk. However, most are much smaller, with the average pecan tree in the 70- to 100-foot range and possessing a 3-foot wide base, according to the National Audubon Society Field Guide to Trees. Pecan trees feature compound leaves, with the central stem of the leaf as long as 20 inches and the 11 to 17 leaflets on this stem in the range of 2 inches to 7 inches in length.
The pecan is native to the rich and fertile ground found in the floodplains of the Mississippi Valley. The tree grows native from eastern Iowa to Indiana and then the range extends southward to Louisiana, Texas and northern Mexico. However, the pecan is an introduced species in the Deep South, as the climate there suits the tree. In fact, the Southeastern states such as Georgia now produce the most pecans for commercial usage. The Southwest has also seen a rapid rise in the acreage devoted to pecan trees. Pecans are also successful transplants today in nations like South Africa, Israel and Brazil.
A pecan tree takes on the shape of a vase as it develops, with a broad, rounded top and massive limbs. The pecan tree's foliage results in lots of shade for the ground below and will change from yellowish-green in summer to all yellow in fall. The bark varies from lighter brown to gray and becomes furrowed and full of ridges as the tree matures. The oblong pecan nut will be as long as 2 inches and have a short pointed tip on one end. The nut has a thin brown husk that splits along four seams to show off the light brown nut inside.
The Texas A&M University Horticulturist Extension site says the ideal spot for pecan trees is along streams and rivers, as the soil is deep and water is abundant. Shallow soil is a problem for pecan trees, as the species features a deep and large root system to provide the specimen with adequate moisture. Pecan trees require full sun to grow, but even in the best settings, pecan need from 15 to 20 years before they start to produce nuts. Pecans also do not tolerate freezing temperatures well.
As many as 500 separate hybrids of the pecan tree exist. The cultivars differ in how many lbs. of pecans they can produce and in the size of the pecan nuts. Other factors to consider when choosing a pecan cultivar are the flavor and oil content of the nuts, how thick the shells will be, how long the tree will take to start producing nuts, and how immune to diseases the hybrid is.