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Black Walnut

Juglans nigra (JOO-glanz NY-gruh)

Family: Juglandaceae Native Canopy (>40 ft)

Black walnut is an edible, deciduous tree in the walnut family (Juglandaceae) and is native to a broad swath of central and eastern North America. It grows well on rich bottom lands, in moist, fertile coves and on lower slopes throughout North Carolina. The species epithet is Latin for "black" in reference to the dark bark and stain of the tree and the nuts. Black walnut prefers moist, organically rich, well-drained soils. It prefers full sun and will tolerate partial shade. However, it is intolerant of full shade. It grows in wet to dry loam, clay or sandy highly acidic to slightly alkaline soil. Its survival, growth and quality in less fertile sites is problematic.This species is particularly resistant to heat, drought and soil compaction. The tree's leaves, stems and roots contain juglone, which inhibits the growth of some plants beneath the tree's dripline. Plants known to be sensitive to juglone include azaleas, peonies and some fruits and vegetables, such as tomatoes, apples and blueberries. Propagate by seed. It has a very deep taproot, making it difficult to transplant. This massive tree can grow to 50 to 90 feet high with a 3 to 6 foot diameter trunk when mature. It has the habit of losing its lower branches to begin its spread at 20 feet above the ground. Each tree bears both male and female flowers (monoecious). In October the trees develop brown to black nuts inside a yellow-green husk that heavily stains skin and clothing. Nut production can sometimes begin as early as 6 years but usually takes 20 years for a substantial crop. The nuts are edible but difficult to remove from the husk, and the fleshy husk can be used to make a brown dye. Once used by Native Americans medicinally, the tree is a scarce, valuable native hardwood used for furniture and veneer. It is a host plant for the larvae of the hickory horndevil ( Citheronia regalis ) moth, banded hairstreak butterflies and the luna moth. Squirrels eat the nuts. The black walnut works well as a shade tree in meadow and woodland locations. It also can be used in butterfly, edible, native and nighttime gardens. Diseases, Insects and Other Plant Problems: Under pressure in some areas from thousand cankers disease. Other potential diseases include anthracnose, bacterial blight, root rot, canker, leaf spot and shoot dieback. Watch for aphids, fall webworm and a variety of foliage chewing caterpillars. VIDEO Created by Laura Barth for "Vegetables, Herbs, Fruits, and Nuts," a plant identification course developed in partnership with Longwood Gardens.

Source: NC State Extension Gardener Plant Toolbox ↗ Reconciled to full toolbox: matched by slug to slug 'juglans-nigra'. Identity (id/common/scientific name) preserved from the original 87-plant Hunnicutt set; attribute data refreshed from the 71-attribute toolbox scrape.

How it fits the guild

Guild layer 1 - Canopy (>40 ft) Optimal soil pH Acid (<6.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Carya ovata Juglans nigra 'Kwik-Krop' Quercus rubra

Full plant profile

Growing Conditions
Plant type
Edible; Native Plant; Tree
Life cycle
Woody
USDA zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Acid (<6.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry | Occasionally Wet | Very Dry
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 50 ft. 0 in. - 75 ft. 0 in. | Width: 50 ft. 0 in. - 70 ft. 0 in.
Growth rate
Rapid
Maintenance
Medium
Canopy layer
1 - Canopy (>40 ft)
Form & Appearance
Habit / form
Open; Oval; Rounded
Texture
Coarse
Foliage
Deciduous
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Alternate
Leaf shape
Lanceolate; Ovate
Leaf margin
Lobed; Serrate
Leaf value
Fragrant; Showy
Leaf size
> 6 inches long, 3-6 inches wide
Hairs present
No
Leaf detail
Leaves emerge late and drop early; 12 to 24 inches long with 15 to 23 leaflets, ovate-lanceolate and finely serrate. 3-lobed leaf scar resembling a monkey face. Leaves drop sporadically during the season. More ovate, more leaflets, and less serrated margins than pecan. Leafing is in late spring with yellow-green leaves and fall color of bright clear yellow.
Fall color
Gold/Yellow; Insignificant
Flower color
Gold/Yellow; Green
Flower form
Catkin; Insignificant
Flower size
3-6 inches
Flower detail
Single-stemmed yellow-green male catkins are 2 ½ to 5 ½ in long, appearing in axillary buds on the previous year's growth. Female flowers are short-spiked in terminal clusters of two to five on the current year's growth. Flowers from April to May and are wind pollinated.
Bloom time
Spring
Fruit color
Black; Brown/Copper; Gold/Yellow; Green
Fruit type
Nut
Fruit value
Edible; Fragrant
Fruit size
1-3 inches long, 1-3 inches wide
Fruit detail
Brown to black nut inside a fleshy, non-splitting, yellow-green husk that heavily stains skin and clothing. Displays in October. Nut inside is edible. Fruit attached singly or in pairs, globular, with pointed apex.
Bark color
Black; Dark Brown
Bark detail
Brown ridged and furrowed with rough diamond pattern bark. Bark is thick.
Stem color
Black; Brown/Copper
Stem detail
V-shaped leaf scar with a bud nestled inside. The surface has raised lenticels and the pith of new branches is chambered with thin, buff-colored diaphrams defining the chambers.
Wildlife & Ecology
Native status
Native
Origin
Eastern United States, west to Texas, and South Eastern Canada
Distribution
Northeast Canada west to North Dakota, Southwest to Utah South to Texas East to Florida.
Wildlife value
This plant supports Hickory Horndevil (Citheronia regalis) larvae which have one brood and appear from May to mid-September. Adult Hickory Horndevil moths do not feed. Also a Larval host for Banded Hairstreak butterflies and Luna moth. Meat of the nut is sweet and edible and a favorite food for squirrels.
Attracts
Moths; Small Mammals
Host plant for
Banded Hairstreak butterflies and Luna moth
Food & Medicine
Edible parts
Fruit; Seeds; Nuts
Harvest time
Fall
Fruit type
Nut

Edibility

Nut is sweet and edible. An edible oil is obtained from the seed, but it tends to go rancid quickly. Used as a seasoning in bread, squash and other foods.

Uses (ethnobotany)

Yellow dye made from fruit husks, seed is used in candy-making, cleaning abrasives, and explosives. Heartwood is of superior quality and value; heavy, hard, and strong with very little warping as it dries. Highly prized for furniture, cabinets, etc.

Landscape Use
Landscape location
Meadow; Woodland
Landscape theme
Butterfly Garden; Edible Garden; Native Garden; Nighttime Garden
Design feature
Shade Tree
Garden tags
#deciduous #Braham Arboretum #NC native #single trunk #native garden #Piedmont Mountains FACU #food source herbage #larval host plant #mammals #coastal UPL #food source fall #shade tree #butterfly friendly #ebh-fn #nuts #native tree #edible nuts #native edible #juglone #ebh #problem for dogs #problem for horses #non-toxic for cats #Audubon #nighttime garden #allelopathic #hickory horndevil moth #moth caterpillar host #food source hard mast fruit #vhfn-n #vhfn #landscape plant sleuths course #wildlife friendly #woodland #hortcontest #dye plant
Problems & Resistance
Insect problems
Walnut Caterpillar
Problems
Allelopathic; Problem for Dogs; Problem for Horses
Resistant to
Drought; Rabbits
Particularly resistant to
Heat, drought, and soil compaction tolerant.
Propagation
Seed

Planted at Hunnicutt

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