The most abundant of the hickories, and common in the eastern half of the United States, it is long lived, sometimes reaching the age of 500 years.

Mockernut male flowers are catkins about 10 to 13 cm (3.9 to 5.1 in) long and may be produced on branches from axils of leaves of the previous season or from the inner scales of the terminal buds at the base of the current growth.

Fruits are solitary or paired and globose, ripening in September and October, and are about 2.5 to 9.0 cm (0.98 to 3.54 in) long with a short necklike base.

The nut is distinctly four-angled with a reddish-brown, very hard shell 5 to 6 mm (0.20 to 0.24 in) thick containing a small edible kernel.

Fourteen mockernut hickory trees in southeastern Ohio produced an average annual crop of 6,285 nuts for 6 years; about 39% were sound, 48% aborted, and 13% had insect damage.

The height growth of mockernut seedlings observed in the Ohio Valley in the open or under light shade on red clay soil was: True hickories sprout prolifically from stumps after cutting and fire.

The relation of height to age is: The current annual growth of mockernut hickory on dry sites is estimated at 1.0 m3/ha (15 ft3/acre).

In fully stocked stands on moderately fertile soil2.1 m3 /ha (30 ft3 /acre) is estimated, though annual growth rates of 3.1 m3/ha (44 ft3/acre) were reported in Ohio (26).

Trimble compared growth rates of various Appalachian hardwoods including a hickory species category dominant-codominant hickory trees 38 to 51 cm (15 to 20 in) in dbh on good oak sites grew slowly compared to northern red oak, yellow-poplar, black cherry (Prunus serotina), and sugar maple (Acer saccharum).

Hickories were in the white oak, sweet birch (Betula lenta), and American beech (Fagus grandifolia) growth-rate category.

About 200 cm (79 in) of annual snowfall is common in the northern part of the range, but snow is rare in the southern portion.

[8][9] In the north, mockernut hickory is found on drier soils of ridges and hillsides and less frequently on moist woodlands and alluvial bottoms.

[7] Mockernut hickory grows primarily on ultisols occurring on an estimated 65% of its range, including much of the southern to northeastern United States.

Along the mid-Atlantic and in the southern and western range, mockernut hickory grows on a variety of soils on slopes of 25% or less, including combinations of fine to coarse loams, clays, and well-drained quartz sands.

In the northern Appalachians on slopes of 25% or less, mockernut hickory grows on poorly drained loams with a fragipan.

On slopes of 25% or less, mockernut grows on wet to moist, fine loam soils with a high carbonate content.

Mockernut hickory nuts are consumed by many species of birds and other animals, including wood duck, red-bellied woodpecker, red fox, squirrels, beaver, eastern cottontail, eastern chipmunk, turkey, white-tailed deer, white-footed mice, and others.

Mockernut hickories also provide cavities for animals to live in, such as woodpeckers, black rat snakes, raccoons, Carolina chickadees, and more.

Because of prolific sprouting ability, hickory reproduction can survive browsing, breakage, drought, and fire.

Top dieback and resprouting may occur several times, each successive shoot reaching a larger size and developing a stronger root system than its predecessors.

In theory, light thinnings or shelterwood cuts can be used to create advance hickory regeneration, but this has not been demonstrated.

Mockernut hickory is extremely sensitive to fire because of the low insulating capacity of the hard, flinty bark.

This fungus kills the bark, which produces a canker, causes heart rot and decay, and can seriously degrade the tree.

In general, the hard, strong, and durable wood of hickories makes them relatively resistant to decay fungi.

The hickory spiral borer (Argilus arcuatus torquatus) and the pecan carpenterworm (Cossula magnifica) are also serious insect enemies of mockernut.

Two casebearers (Acrobasis caryivorella and A. juglandis) feed on buds and leaves; later, they bore into succulent hickory shoots.

Mockernut is not easily injured by ice glaze or snow, but young seedlings are very susceptible to frost damage.

This feeding combined with insect and disease problems eliminates the annual nut production, except during bumper seed crop years.

It is used for ladder rungs, athletic goods, agricultural implements, dowels, gymnasium apparatus, poles, shafts, well pumps, and furniture.

Geneticists recognize that mockernut hickory hybridizes naturally with C. illinoensis (Carya x schneckii Sarg.)