Shagbark Hickory (Carya ovata)
This tree plays a critical role in maintaining the biodiversity of our native forests.
Appearance. The shagbark hickory is a large forest tree, reaching a height of nearly 100 feet in Minnesota, but reaching 130 feet in the southeastern states where the summers are long and humid. During winter, the leaf buds at the tips of the twigs are protected by large, conspicuous “bud scales” that resemble petals of a flower when they unfold in the spring. The leaves are large and are known as compound because each is made up of five or seven individual leaflets. The bark of young trees is ash-gray and smooth. Over time, the bark develops long, flat, plate-like strips that tend to loosen and curl away from the trunk. This gives the trunk a “shaggy” appearance, the trademark feature of the species.
Range and Habitat. Shagbark hickory is common in the eastern half of the United States, reaching Minnesota at the extreme northwestern corner of its range. In Minnesota, shagbark is easiest to find in the stream-dissected terrain of the bluff country of the southeastern counties. It typically inhabits wooded slopes and ridge tops, but it also occurs on level terrain. It does very well in dry soils, but if given a chance it will thrive in moist soils, too. Shagbark won’t be found in a pure stand; it’s usually scattered among oaks. Perhaps the best place to see shagbark hickory in Minnesota is at Great River Bluffs State Park near Winona.
Natural History. Shagbark hickory, like the oaks, is slow-growing and long-lived. Each tree will have separate male and female flowers. Male flowers appear in May and are borne in clusters of long, dangling catkins 4–6 inches in length. They produce pollen that is spread by the wind. The female flowers appear about the same time but are small, green, and hard to spot. The fruit is a nut that ripens in the fall. It is enclosed in a thick, woody husk that splits into four segments to release the nut.
Uses. Trees produce a large crop of sweet-tasting nuts every one to three years. In some parts of the country, a crop of hickory nuts is highly anticipated and valued, but there appears to be little or no tradition of gathering hickory nuts in Minnesota. Lumber made from shagbark hickory is valued for its strength, toughness, and flexibility, but is not widely used in construction or furniture making. It is usually reserved for specialty items such as shovel handles and sporting equipment, and for smoking meat. The tree is generally disease- and pest-free, making it a desirable shade tree anywhere in the southeastern third of the state. Perhaps the best and highest use of shagbark is the role it plays in maintaining the biodiversity of our native forests. The nuts provide food for many forest animals, and a variety of birds nest in its branches. In summer little brown bats and tricolored bats will spend the night sheltered under a protective flap of bark. In all regards, shagbark hickory is a tree well worth knowing.