Signed in as:
filler@godaddy.com
Black Walnut
(Juglans nigra)
In ecological terms, Black Walnut is a titan tree and, in commercial terms, it is highly coveted for its dense, strong, beautiful wood. Black Walnut is native to eastern North America, growing in fertile bottomlands, coves, and gentle slopes throughout the Carolinas. Its dark, lacy, diamond-shaped bark makes Black Walnut easy to identify in the forest.
Black Walnut trees are monoecious, meaning each tree bears both male and female flowers. As early as 6 years old, Black Walnut trees can begin to produce fruit. However, it is more common that fruit production begins around 20 years old. Their rugged fruit is protected by a pale green/chartreuse colored husk. The nuts are edible and their flavor is praised as a special ingredient or as a topping. The nut shells are very difficult for people to crack without proper tools, but squirrels do just fine without any help at all.
If you plan on harvesting Black Walnut fruits, they will need to be hulled. This means removing their outer husk to reveal the nut within. When hulling, it's wise to wear latex gloves and clothes that didn't cost you much and that you don't mind ruining. Black walnuts contain natural juglone and tannins that oxidize and stubbornly bind to anything they come in contact with. Right away. For a good long time.
When planning the placement of Black Walnut for green infrastructures or open landscaping, it's important to account for its self-serving/self-preserving chemical profile. Black Walnut produces a natural chemical compound called juglone which is secreted from its roots, leaves, and nut hulls. This compound creates a suppressive zone beneath its canopy that inhibits other plants and tree species from thriving within its vicinity. Hornbeam, Hop-Hornbeam and Pines are highly sensitive to juglone, so plan for good distance between them.
Commercially, Black Walnut wood is extraordinary when compared to other hardwoods. It is a highly valued, high end, native hardwood used for very fine furniture and outstanding, quality veneers.
Toxicities:
Black Walnut shavings or sawdust should not be used for equine bedding. Even in small amounts (as little as 10%-20%) can be fatal within mere hours following exposure.
Aging, fallen walnuts can carry a mold toxin that, if ingested, can cause digestive distress in dogs.
For information regarding common diseases and pests of Black Walnut trees visit Clemson Cooperative Extension's Home and Garden Information Center.
Copyright © 2026 Skipping Rock Farm - All Rights Reserved.
Conditions
Light:
Full Sun
Black Walnut does not tolerate shade very well and will suffer slow or stunted growth and poor fruit production if it's denied 6 to 8 hours of sunshine every day.
Soils:
- Sandy Loam, Silty Loam
- Unrestricted, easily penetrable soils to 48" below grade allowing its massive taproot to grow unimpeded.
- Soil pH 6.5 - 7.0
- Moist, Well Drained
Tolerances:
- Highly Drought Tolerant
- Intolerant to Flooding and Waterlogged Soils.
- Intolerant to sharing nutrients with other plants and grasses such as tall fescue.
- Intolerant to heavy ice/snow.
Growth
Black Walnut is expected to grow fairly quickly.
In a competitive forest environment, Black Walnut typically forms a relatively narrow, compact shape with a high-set, small, rounded crown. It will self-prune as it progresses upward, competing for sunlight. In an open-grown setting, expect a shorter trunk with a massive, wide-spreading, rounded crown.
The expected lifespan of Black Walnut is around 80 years within a competitive forest and 200 years when open-grown.
Mature height will range from 70' to 90' tall with a spread of 30' to 50' wide. Expect a trunk diameter of 2' to 2.5' in a competitive woodland habitat and up to 6' in an open-grown environment.
Manufacturer's Specs
Carbon Storage Characteristics:
(High)
- Moderate to Rapid growth
- Moderate Lifespan
- High Density Wood
Carbon Storage Estimates for Lifetime/Mature Tree:
- CO₂e = 2.0 to 4.5 tons
Pollution/Dust Interception:
- Medium-Low
Tropospheric Ozone Tolerance:
- High
Flood/Stormwater Abatement:
- Medium
Oxygen Yield:
- Medium-High