black walnut

Juglans nigra

Description:

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.

Details:

black walnut

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

ITIS TSN: 19254

Category: Dicot

Taxonomy

Kingdom: Plantae

Subkingdom:

Super Division: Spermatophyta

Division: Magnoliophyta

Subdivision:

Class: Magnoliopsida

SubClass: Hamamelididae

Order: Juglandales

Family: Juglandaceae

Counties: Ashland, Barron, Bayfield, Brown, Buffalo, Chippewa, Columbia, Crawford, Dane, Dodge, Dunn, Eau Claire, Fond du Lac, Grant, Green, Green Lake, Iowa, Jefferson, Kenosha, La Crosse, Lafayette, Langlade, Lincoln, Manitowoc, Milwaukee, Monroe, Oconto, Outagamie, Pepin, Racine, Richland, Rock, Rusk, Sauk, Taylor, Trempealeau, Vernon, Walworth, Washington, Waukesha, Winnebago, Wood

Natural Community:

Curtis Community: Southern Wet-Mesic Forest

Coefficient of Conservation: 3

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

NR40 Listed Plant	Noxious Weed:	Invasive Species (NR40):	Threatened/Endangered:	WI Natural Heritage Index:	Wetland Status
					FACU

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:

Adapted to Coarse Textured Soils: No

Adapted to Medium Textured Soils: Yes

Adapted to Fine Textured Soils: No

Anaerobic Tolerance:

CaCO3 Tolerance: High

Cold Stratification Required: No

Drought Tolerance: Low

Fertility Requirement: High

_Fire Tolerance: High

Frost Free Days, Minimum: 170

Hedge Tolerance: None

Moisture Use: High

pH (Minimum): 4.6

pH (Maximum): 8.2

Planting Density per Acre, Minimum: 100

Planting Density per Acre, Maximum: 800

Precipitation (Minimum): 30

Precipitation (Maximum): 60

Root Depth, Minimum (inches): 40

Salinity Tolerance: None

Shade Tolerance: Intolerant

Temperature, Minimum (°F): -28

Plant Spacing (min):

Plant Spacing (max):

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:

Benefits:

Berry/Nut/Seed Product:	Christmas Tree Product:	Fodder Product:
Yes	No	No

Fuelwood Product:	Lumber Product:	Naval Store Product:
High	Yes	No

Nursery Stock Product:	Palatable Browse Animal:	Palatable Graze Animal:
Yes	Low	Low

Palatable Human:	Post Product:	Protein Potential:
Yes	No	Low

Pulpwood Product:	Veneer Product:
No	Yes

Benefits:	Wildlife Food Value:	Wildlife Cover Value:

References:

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.
iNaturalist Database – Juglans nigra
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.
USDA Plants Database – Juglans nigra
USFS Fire Effects Information System – Juglans nigra
Wisflora Database – Juglans nigra

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