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Pignut Hickory

Carya glabra

Walnut Family (Juglandaceae)

Introduction: The hickory tree's strong yet flexible wood and excellence as fuel made it invaluable to pioneers. The pignut hickory offers lightly hung foliage in summer that casts a medium shade. In winter its open habit and bark are of interest. The hickory is particularly beautiful when winter buds open in late spring; the bud scales fold back, petal-like, as new foliage emerges. Pignut hickory's nutritious nuts attract wildlife.

Culture: This very large, slow-growing species prefers well-drained, acidic soil and full sun or part shade. It is quite drought-tolerant, and will grow well in sand or clay. Wild hickories have deep tap roots that make them difficult to transplant. Also, it is worth noting that all hickories leaf out late in the spring. Pignut hickory is best planted in a park-like area where its large size, leaf litter, fruit and twig drop will not be problems. Its savory nuts attract squirrels and other animals that may be unwanted in residential areas. The hickory bark beetle may be a significant pest on this tree. This tree is resistant to Verticillium wilt.

Botanical Information

Native habitat: Maine to Ontario, south to Mississippi, Alabama and Florida.
Growth habit: This long-lived tree has a tapering trunk with an open, oval crown of slender branches.
Tree size: A slow-growing tree that can attain a height of 50 to 60 feet and a 25- to 35-foot spread. It can grow to 100 feet tall in the wild.
Flower and fruit: Male flowers are yellow-green catkins. Female flowers are in 2- to 5-flower spikes. Fruit is a bitter nut in a green husk.
Leaf: An 8- to 12-inch-long compound leaf with five leaflets (shagbark hickory leaves have seven leaflets). The lowest two leaflets are one-third the size of the upper three leaflets. Dark yellowish-green foliage turns golden yellow in fall.
Hardiness: Winter hardy to USDA Zone 4.

Additional information: The genus name, Carya, is from the Greek name for the walnut tree (karya); the species name, glabra, means glabrous or smooth, referring to the foliage. Although only a few hickory species exist outside of eastern North America (in eastern Asia), fossils indicate that hickories were once found in central Europe, China, the former Soviet Union, the western and southwestern U.S. and Alaska.

Pignut hickory fruit has a small kernel with variable flavor, usually bitter and is fit to be eaten only by "pigs and other animals."

The wood of hickory is famously heavy and tough yet flexible and shock-resistant. Because of these qualities, it is often used in sporting goods, such as skis, and for tool handles. Hickory wood also has low conductivity of heat. This characteristic made hickory the wood of choice for wagon wheels and sulkies for harness horses. It was used to make automobile parts in the early days of that industry. Pignut hickory is stronger than steel, yet more elastic, less brittle and less conductive of heat.

A 105-foot national champion pignut hickory is in Georgia. Pignut hickory was first cultivated in the U.S. in 1750.