There may be some disagreement on how to pronounce the name, but there is little disagreement about the deliciousness of northern pecan’s rich, buttery nuts and the beauty of its bright-yellow fall foliage. Northern pecan grows 70-100 feet tall and about half as wide. Although it prefers a long, warm growing season, some of these trees are found as far north as Wisconsin. Carya illinoinensis is named after Illinois, where it was first described, and it appears from Iowa to Texas and Mexico. In the wild, it’s often found in the deep, moist soils along river banks; however, it flourishes in a wide range of soils and full sun. Open-grown pecan trees have massive trunks and oval to rounded, wide-spreading crowns of branches that extend far down the trunk and grow outward in an upright, spreading fashion. The lower branches of older trees are wide-sweeping, with their tips almost touching the ground.
The fastest grower of the hickory species and the best of the hickories for fruit production, northern pecan often survives for up to 300 years. Pecan trees are able to increase genetic diversity through dichogamous flowering, which means that the male and female flowers do not mature at the same time. They’re located on different parts of the tree, with the female nutlets emerging from current-season growth and the male catkins developing on the previous year’s growth. To achieve pollination, and because cross-pollinated pecans are usually larger and of higher quality, several trees should be planted for optimal crops. Bare-rooted saplings begin to bear nuts after 3-4 years, eventually producing 70-150 pounds of nuts per year. Plant so that each tree has plenty of space to grow. Nuts are ready for harvest around mid-October.
Northern pecan is in the same family as black walnut, and both produce the chemical juglone, which inhibits the growth of plants that are sensitive to the chemical. This process, known as allelopathy, is a way of protecting the plant not only from other competitive plants but also from microbial pathogens. Fortunately, many of our native trees and shrubs are resistant to juglone.
Pecans are the only major tree nut indigenous to America. More than 100 million years ago, the mighty trees grew along the fertile banks of rivers flowing through the plains of the southeastern US. Much later, Native Americans transported pecans on their canoe trails. The word “pecan” came from their word, paccan, meaning “food which has to be cracked out of a hard shell.” They made pecan a staple of their diet and used them for barter. Early settlers also ate pecans and sold them for cash. Unfortunately, they would fell the tree to harvest the entire crop, leading to an eventual scarcity of pecan trees.
Native habitats include banks of rivers and streams. Pecans are suitable for naturalized, woodland, or recreational areas and as part of edible or pollinator gardens. The tree produces a high amount of litter, so it may not be the best choice for manicured landscapes.
Plant Characteristics:
Grows 70-100’ tall and 40-75’ wide.
Requires full sun.
Prefers moist, well-drained soils, but grows in sandy, loamy, silty, and clay soils.
Monoecious flowers occur in April-May with a 3-4" trio of yellow-green male catkins.
Small, yellowish-green female flowers grow on spikes at the tips of shoots. Light brown, wrinkled fruits are encased in thick hulls in clusters of four. The green husk changes to black when ripe.
Compound leaves up to 20" in length consist of 9–17 lance-shaped leaflets 4–8" long. The leaflets are slightly toothed. Leaves change from medium green in the spring to dark yellow-green in late summer to golden yellow and finally golden-brown in fall.
Trunks can grow to 6 feet in diameter. Bark is gray to brownish-black, becoming scaly or slightly furrowed with age.
Wildlife Value:
Northern pecan is a host plant for 231 species of Lepidoptera larvae, including the tuliptree, luna and polyphemus silkmoths. The nuts are eaten by wild turkeys, wood ducks, crows, blue jays, squirrels, opossum, and raccoons. White-tailed deer sometimes browse older pecan trees.
Medicinal, Edible, and Other Uses:
Native Americans may have created the original nut milk, called powcohicora, by fermenting pecan powder into a drink.
Pecans are a rich source of nutrients such as healthy fats, fiber, manganese, protein, zinc, and thiamine. Pecans are eaten as a snack and in a variety of dishes, such as salads, casseroles, praline candy, and pecan pie.
The wood is popular for making furniture and wood flooring. It’s also used as a flavoring fuel for smoked meats, giving grilled food a unique taste.