Photo: William (Ned) Friedman, CC BY-SA 4.0 · Wikimedia Commons
Pignut Hickory
Carya glabra
Also called pignut, sweet pignut, smoothbark hickory, broom hickory, coast pignut hickory.
The everyday hickory of Appalachian ridges: tight gray bark, pear-shaped nuts that fox and gray squirrels live on through winter and rich gold fall color.
Wildlife valueDrought tolerantFall color
- Type
- Large tree
- Mature height
- 50–80 ft
- USDA zones
- 4–9
- Growth rate
- Slow
- Sun
- Full · Part
- Soil moisture
- Dry · Average
210
Pignut hickory is the everyday hickory of dry ridges and slopes from New England south to Florida and west to Illinois, Missouri and Texas; it is the commonest hickory of the Appalachians. It is the plain one: slender hairless twigs, leaves of five or seven leaflets that turn rich gold in fall and gray bark that stays tight and shallowly ridged, rarely shaggy. The nut is pear shaped in a thin husk that splits only halfway, and the kernel is sweet on one tree and bitter on the next, which is why the settlers left it to the hogs. Squirrels do not mind: pignuts feed fox squirrels and gray squirrels prefer them through fall and winter in parts of New York; chipmunks, black bears, gray foxes, raccoons, woodrats, wild turkeys and wood ducks eat them; hollow hickories are squirrel den trees. Hickory is a keystone genus, host to 213 kinds of caterpillars, the luna and regal moths and the hickory hairstreak among them. Ideal for a dry ridge or upper slope, a woodlot with oaks or the back of a big lawn.
It is seldom sold, because the taproot makes it hard to transplant, yet it stands on the driest ridges, is the most shade tolerant of the hickories and the least tolerant of flooding. Seedling trees bear in quantity at about 30 years and then a good crop every year or two; a tree can bear for three centuries, and settlers split its saplings into brooms.
How to grow Pignut Hickory
Pignut hickory is hardy in zones 4 through 9 and 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 reaches 50 to 80 feet tall and 25 to 40 wide, so plant it 25 feet from the house and off the drive.
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, flare at grade, native soil back in, mulch off the trunk, no stake unless it leans. Sow nuts in fall an inch deep under hardware cloth, or squirrels dig them, or soak them two to four days, hold them damp in the refrigerator for 90 to 120 days and sow in spring. 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.
Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.
- Six trees not to plant near a house, and what to plant instead
- Pruning at the branch collar, and when to make the cut
- Native trees and shrubs for butterflies and moths: host plants first, nectar second
- Native trees and shrubs for wildlife: what deer, squirrels, bears, bats and turtles get from a planting
- Ten planting mistakes that quietly kill trees
More like this
