• Central Park Conservancy Logo
  • Official Caretakers of Central Park

Black Walnut

Black Walnut Tree
If you run regularly in Central Park, you've probably noticed black walnut trees, if only because of their yellow fruit that resembles racquetballs strewn in several locations along the Central Park loop. Native to North America, black walnut was, and still is, an important commercial tree in the United States. The wood is beautiful and straight-grained. Black walnuts are considered delicious by humans and animals, though getting at the nutmeats is a challenge that can leave fingers deeply stained. The ground shells are used in many commercial applications, and during WWII were used to clean airplane pistons. The tree's roots emit a toxin that may be harmful to other plants; care must be taken in choosing what to plant near them.

Common Name: Black Walnut

Scientific Name: Juglans nigra

Origin: New England down through Texas

Family: Juglandaceae

Size: 50 - 75' tall

Form: Open, oval crown

Culture: Thrives in full sun; prefers moist, well-drained, rich, deep soil


Alternate arrangement, rows of up to 23 leaflets, leaflets up to 5" long


Male flowers are catkins with small scaly, cone-like buds; female flowers are up to eight-flowered spikes


Nut, semi-fleshy covering, change green to black and break open


Dark brown to grayish-black, deep narrow furrows, diamond-shaped pattern