black walnut

Juglans nigra

Image of black walnut grove.
Photo downloaded from Bugwood Database, photographer David Stephens.


Juglans nigra, also known as the Eastern black walnut, is a species of deciduous tree in the Juglandaceae family. It is native to the Eastern United States and can be found from southern Ontario and Quebec, to the Gulf of Mexico, including Wisconsin.

Morphologic characteristics of Juglans nigra include:

  • large tree, reaching heights of up to 100 feet
  • straight trunk, with a dark brown, deeply furrowed bark
  • pinnately compound leaves, with 11-23 leaflets that are lanceolate to ovate in shape
  • male and female flowers on separate trees, with the males being in drooping catkins, and the females being small and inconspicuous
  • large, round, green fruit, which mature in September to October and contain a large, edible, oily nut encased in a thick, hard shell

It can be found in different habitats such as bottomlands and well-drained uplands, and it’s also commonly used as a shade tree, and for its wood and nuts.


black walnut

USDA Symbol: Common Name: Scientific Name:
JUNI black walnut Juglans nigra

ITIS TSN: 19254

Category: Dicot


Kingdom: Plantae


Super Division: Spermatophyta

Division: Magnoliophyta


Class: Magnoliopsida

SubClass: Hamamelididae

Order: Juglandales

Family: Juglandaceae


Natural Community:

Curtis Community: Southern Wet-Mesic Forest

Coefficient of Conservation: 3

Duration: Growth Habit: Native Status:
Perennial Tree L48(N)CAN(N)

Active Growth Period: Spring

After Harvest Regrowth Rate:

Bloat: None

Carbon to Nitrogen Ratio: High

Coppice Potential: Yes

Conspicuous Fall Color: No

Fire Resistant: No

Flower Color: Yellow

Conspicuous Flower: No

Foliage Color: Green

Foliage Light Porosity Summer: Porous

Foliage Porosity Winter: Porous

Foliage Texture: Medium

Fruit/Seed Color: Brown

Fruit/Seed Conspicuous: Yes

Growth Form: Single Stem

Growth Rate: Rapid

Height at Base Age (Max): 35

Height at Maturity: 100

Known Alelopath: Yes

Leaf Retention: No

Lifespan: Moderate

Low Growing Grass: No

Re-sproutability: Yes

Shape and Orientation: Erect

Toxicity: Slight

Height (min):

Height (max):

Root Type:

Leaf Type:

Leaf Arrangement:

Leaf Shape:

Leaf Margin:

Vein Pattern:

Bloom Period: Commercial Availability: Fruit/Seed Abundance:
Late Spring Routinely Available Low
Fruit/Seed Period Begin: Fruit/Seed Period End: Fruit/Seed Persistence:
Fall Fall No
Propogated by Bare Root: Propogated by Bulbs: Propogated by Container:
Yes No Yes
Propogated by Corms: Propogated by Cuttings: Propogated by Seed:
No Yes Yes
Propogated by Sod: Propogated by Sprigs: Propogated by Tubers:
No No No
Seeds per Pound: Seed Spread Rate: Seedling Vigor:
40 Slow High
Small Grain: Vegetative Spread Rate: Propagation Treatment:
No None
Days to Stratify: Direct Sowing Time:


  1. Burns, Russell M., Honkala, Barbara, H. Silvics of North America, Volume 2, Hardwoods. United States Department of Agriculture (USDA), Forest Service, Agriculture Handbook 654, pages 391-399.
  2. iNaturalist DatabaseJuglans nigra
  3. Smallwood, Christopher J.; Ethington, Matthew J.; Ginzel, Matthew D.  Managing Thousand Cankers Disease in High-value Plantings of Black Walnut (Fagales: Juglandaceae) in Washington State. Journal of Integrated Pest Management, Volume 13, Issue 1, 2022, 5.
  4. USDA Plants Database –  Juglans nigra
  5. USFS Fire Effects Information SystemJuglans nigra
  6. Wisflora Database – Juglans nigra

Return to Native Plants page