Pignut Hickory

Size, growth and what to expect

Pignut hickory stands 14 to 20 feet at 20 years and 40 to 61 feet at 50, depending on the site. That is about the foot a year our growth estimator uses for a slow tree. Trees typically live 200 years, and the oldest known has been ring-counted to 325.

In a yard expect 50 to 80 feet and a spread of about 40. Forest trees often reach 80 to 90 feet with trunks 3 to 4 feet through. The nut is pear shaped, in a husk that splits only to the middle, with a thick shell and a kernel that is edible but can be bitter. Several kinds of squirrel get an estimated 10 to 25 percent of their diet from the nuts.

It grows wild across nearly all the East, from Massachusetts and southern Ontario to Michigan and Illinois and south to east Texas and central Florida, mostly on dry ridgetops and slopes.

How to grow Pignut Hickory

Pignut hickory grows in full sun or part shade on any well-drained soil; it likes a light loam best, takes a dry ridge once established and will not stand flooding. It grows tall and wide, so plant it 25 feet from the house and off the drive. Set trees 25 to 40 feet apart.

Saplings ship bare-root or potted. Plant a dormant sapling from leaf fall until bud swell, in a hole deep enough for the taproot to hang straight and wider than the rest. Set the flare at grade, put the native soil back in, and keep mulch off the trunk. Stake it only if it leans. Sow nuts in fall an inch deep under hardware cloth, or squirrels dig them up. For spring, soak them two to four days, then hold them damp in the refrigerator for 90 to 120 days. They come up in late spring and make 3 inches of top the first year while the root goes down.

Water every week or two the first summer when rain is short. Deer only occasionally browse pignut, but rabbits gnaw hickory bark, so tube the stem for three years and keep the mulch thin at the base against voles. Prune in the dormant season only to keep one leader and cut little; hard pruning brings water sprouts, and a big wound lets in trunk rot, pignut's commonest disease.

Growth is slow, about 20 feet in 20 years. Seedling trees bear in quantity at about 30 years, a good crop every year or two. Male catkins and female flowers share a tree, the catkins usually shedding first, so a second hickory nearby improves the set. Drought-stressed trees draw the hickory bark beetle, which turns a tree red within weeks; twig girdlers clip young trees and leaf galls are harmless.