SelecTree

A Tree Selection Guide

BLACK WALNUT

Juglans nigra

FAMILY Juglandaceae

SYNONYMS

ADDITIONAL COMMON NAMES

AMERICAN WALNUT

EASTERN BLACK WALNUT

NOYER NOIR

See: all Juglans
Photo locations: Morton Arboretum - Lisle, IL, Louisiana State Arboretum - Ville Platte, LA, Los Angeles County Arboretum - Arcadia, CA, Hoyt Arboretum - Portland, OR, Cal Poly State University - San Luis Obispo, CA, Davis, CA and Arnold Arboretum - Boston, MA
by C. Stubler, J. Reimer, M. Ritter

GENERAL INFO

Fairly drought tolerant. Requires a moderate amount of water. Hardy to 10 degrees F. Wood is valued by woodworkers for its strength and beauty. Black Walnut produces Juglone, an organic compound that is harmful or toxic to many other plants. The toxicity extends out from the trunk with the greatest concentration at the trees dripline.
Native range: Eastern North America

TREE CHARACTERISTICS

Tree Shape: RoundedFoliage Type: DeciduousMaximum Tree Height: 80 feetCanopy Width: 70 feetGrowth Rate: ~24 in/yearLeaf Arrangement and Leaf Form: Alternate, Pinnately CompoundLeaf Shape: Spear-shapedLeaf color: GreenFall Color: YesFlowers: Inconspicuous, FragrantFlower Type: Has separate male and female reproductive parts on the same tree (monoecious)Flower Time: SpringFruit: Large Brown, Yellow or Mostly Green NutFruiting time: FallFruit Value: EdibleBark Color: Black or Dark Brown, FissuredLitter Type: Dry Fruit

SITE CONDITIONS

Recommended Planting Area: Greater than 7'Water Use Rating: MediumSunset Climate Zone: 1 - 9, 14 - 21Shade Tolerance: NoUSDA Hardiness Zone: 5, 6, 7, 8, 9Soil Texture: Loam or SandSoil pH: Very Acidic to Slightly AlkalineSalt Tolerance: Moderate

CONSIDERATIONS

Branch Strength: StrongRoot Damage Potential: HighPotential health issues: Allergy, IrritantBiogenic Emissions: ModerateWildlife interactions: Attracts squirrelsDisease and Pest susceptibility: Armillaria, Anthracnose, Phytophthora, Root Rot and Beetle Borers, CaterpillarsDisease Resistance and Pest Resistance: Verticillium and Gypsy MothGypsy MothUtility Friendly: NoWCISA Appraisal: Suggested LCANT 24" box, Group 4, Approx. cross sectional area 4.75 sq. in.

External Resources

WikipediaiNaturalistKewThe Wood Database

CITE THIS TREE

"SelecTree. UFEI. "Juglans nigra Tree Record." 1995-2025. Cal Poly State University, San Luis Obispo. Accessed on May 18, 2025."
< https://selectree.calpoly.edu/tree-detail/747 >

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