Black walnut

Juglans nigra

Nut tree
Native
Allelopathic (juglone)

Pet & Human Safety

People: No hazard foundPets: Toxic to dogs and horses

Human edibility

Edible

Edible parts

nuts (kernels)

Hazardous parts

Not yet checked.

Preparation

Not yet checked.

Hazard type

Not yet checked.

Hazard route

not applicable

How complete this information is

The safety information on this page is partial. Where a source covers a point, it is shown; where none does, the page says so.

Toxic to pets

Toxic to dogs and horses

ASPCA, Black Walnut. Dogs: moldy nuts and hulls can cause tremors and seizures; ingesting shavings can cause incoordination. Horses: laminitis and colic. Cats: non-toxic. ASPCA lists the toxic principle as unknown.

Look-alike warning

Could be mistaken for Plants that share its name. To tell them apart: Black walnut (Juglans nigra) is a different tree from English or Persian walnut (Juglans regia) and from butternut (Juglans cinerea). NC State lists pecan (Carya illinoinensis), Kentucky coffeetree (Gymnocladus dioicus), butternut (Juglans cinerea) and English walnut (Juglans regia) among plants it is often confused with. The juglone effect on neighbouring plants is named for black walnut by NC State..

Poison control

If someone has collapsed, cannot be woken, is having a seizure or has trouble breathing, call 911 now. For any other possible poisoning, call Poison Help: 1-800-222-1222.

Emergency number source: U.S. federal law (47 U.S.C. § 251(e)(3)), read 2026-10-07.

Naturalist Lore

Historical Background & Breeding Lore

The history of this plant and its name, and how it was bred, where we have them.

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Care

Hardiness zones: USDA hardiness zones 4a to 9b (US system).
Mature size: Height 50-75 ft (NC State's description says 50-90 ft); width 50-70 ft; trunk 3-6 ft across when mature.
Family: Juglandaceae (walnut family)
Where it comes from: Eastern United States west to Texas, and southeastern Canada (NC State); northeast Canada west to North Dakota, southwest to Utah, south to Texas, east to Florida.

Soil & Drainage

Pruning & Flush Rhythm

Feeding Schedule

How to prepare the soil, when and what to feed, and how and when to prune where that applies.

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