805 Carya illinoinensisCommon Names: pecan Family: Juglandaceae (walnut Family)
The pecan tree is a large, vase-shaped tree with deciduous feather-like compound leaves. Under ideal growing conditions, a pecan tree can get 180' tall and have a trunk 7 ft (2.1 m) in diameter. The pecan tree has gray bark that becomes reddish brown with age, developing narrow furrows and rough, angled ridges. The leaves are 12-20 in (30.5-50.8 cm) long, with 11-17 leaflets, each 4-7 in (10.2-17.8 cm) long and tapering to a sharp point. The foliage has a disagreeable odor when bruised. Pecans are pollinated by the wind and both male and female flowers are on the same tree. The male flowers are in hanging catkins and the female flowers in terminal spikes. The fruit is technically a drupe, consisting of a cylindrical stone (the nut) enclosed in a thick green husk that splits open when mature. Crack open the nut to get at the delicious, oily, nutrient-rich kernels.
More than 500 pecan cultivars have been named. These vary in productivity from 400-1000 lb (182-453 kg) per mature tree. They also vary in: nut size which ranges from 1-3 in (2.5-7.6 cm), kernel quality (flavor and oiliness), shell thickness, tendency to bear in alternate years, age at first bearing (10-20 years), disease resistance, and length of time required to mature a crop (170-290 days). "Paper shell" refers to any cultivars that have thin shells.
Pecan, Carya illinoinensis, trees grow naturally in the rich bottomland soils of the floodplains and valleys of the Mississippi River and its tributaries, from Iowa and Illinois to the Gulf of Mexico. They also occur along larger streams and rivers in Oklahoma, Texas and northern Mexico. Pecans are cultivated throughout much of the southern U.S. Most commercial production is in Georgia, Alabama, Mississippi, Louisiana, Texas, and increasingly in New Mexico, where they are grown with irrigation. Pecans also are grown commercially in Spain, France, Israel, South Africa and Australia.
CultureThe pecan is a slow growing tree that takes 15-20 years before it starts bearing and requires a frost free period of 6-9 months for its nuts to mature. Best production occurs on trees 75-225 years old, and mature trees can produce 400-1000 lbs. of nuts per year! Pecan trees sometimes suffer from insect (especially aphid) damage, and it is just impractical to spray individual trees or small groves. Large groves are sprayed from crop dusting aircraft. Pecan trees often suffer from zinc deficiency, and they require lots of nitrogen fertilizer. In most soils, pecan trees should be sprayed with zinc sulfate every 2-4 weeks in the spring and early summer. Commercial growers have the leaflets analyzed for nutrient needs, and the homeowner can get this service too. Light: Full sun. Moisture: Pecan trees require 1-2 in (2.5-5.2 cm) of rain per week during the growing season. They can tolerate flooding during the dormant season, but not when they have leaves. Hardiness: USDA Zones 5 - 9. There are cultivars developed specifically for zone 5 that can produce ripe nuts as far north as Ontario, and cultivars for the deep south that require 9 months to mature a crop. Propagation: Pecan cultivars usually are grafted onto seedlings of vigorous stains grown specifically for the purpose. Most nurseries sell pecan trees that have 2-3 year old roots and one year old scions. The little trees have long taproots and are more difficult to transplant successfully than most other fruit or nut trees.
The stately pecan tree makes a wonderful shade tree, with its tall, straight bole and rounded crown of feathery foliage. A single specimen will make a homeowner proud. And, the squirrels usually can't get ALL the nuts! Plan for its ultimate size, though. Most people who grow pecans for the nut crop plant them 30-40' apart and expect to thin every 50 years or so.
There are about 25 other species of hickories (genus Carya), all native to eastern North American or southeastern China. The pecan is one of very few North American plants to have been domesticated and developed into a commercial crop; and it's certainly the most valuable and the most widely grown. What would life be like without pecan pie? Native Americans made a creamy liquid called "hickory milk" by smashing pecan kernels and boiling in water, then straining; they drank it and used it to thicken soups and flavor corn cakes and other dishes. Pecan trees have hard, reddish-brown wood that is used to make tool handles, flooring, veneer and furniture.
Steve Christman 8/30/00; updated 11/9/03, 8/19/04