Black walnut - Juglans nigra (Care, Characteristics, Symbolism, Images, Toxic)

Black walnut

Also known as: Eastern Black Walnut, Eastern american black walnut

Black walnut is a large riparian zone tree native to North America. It is cultivated for nutritious walnuts and high-quality dark timber. Black walnut produces juglone, a compound that inhibits the growth of other plants in the black walnut tree’s proximity, so it may be undesirable near lawns and gardens. It is susceptible to a Thousand Cankers Disease.

Scientific classification

Species

Black walnut (Juglans nigra)

Beeches, walnuts, and allied trees

Instantly identify plants with a snap

Snap a photo for instant plant ID, gaining quick insights on disease prevention, treatment, toxicity, care, uses, and symbolism, etc.

Download the App for Free

Toxic to Human & Pets

Toxicity

Perennial

Lifespan

Tree

Plant Type

Mid spring, Late spring, Early summer

Bloom Time

Fall

Harvest Time

20 m to 45 m

Plant Height

20 m

Spread

Green

Leaf Color

1 cm to 3 cm

Flower Size

Green, Brown, Copper, Black, Yellow, Gold

Fruit Color

Green, Yellow

Flower Color

Brown, Black

Stem Color

Winter dormancy

Dormancy

Deciduous

Leaf type

5 - 35 ℃

Ideal Temperature

Spring

Growth Season

Rapid

Growth Rate

Images of Black walnut

Attributes of Black walnut

Growth Rate

During the spring, black walnut experiences a rapid growth rate, expressed in quick leaf expansion and soaring heights, yielding a vigorous canopy. This speed fosters its distinctive extensive root system. Temporal variations exist, but these are pronounced in spring, crucial for seed germination processes.

Distribution of Black walnut

Distribution Map

Black walnut is native to eastern North America, where it grows in moist woodland areas. This tree has been cultivated commercially for its nuts throughout its native range as well as in Europe and Asia.

Native

Cultivated

Invasive

Introduced

No species reported

Discover plant distribution and habitat

Gain insights into where plants thrive and how they adapt, helping you identify, cultivate, and protect them with essential information on habitats, distribution maps, and climate trends.

Download the App for Free

Habitat

Woods, hillsides

Hemisphere Trend Curve

Northern

Sorthern

Flowering

Fruiting

Culture

Garden Use

Black walnut is a beautiful enough tree to have earned an Award of Garden Merit. It is commonly grown commercially, in large public parks or very big yards (it usually grows to around 30 m tall), as it provides excellent shade; but is too big for urban areas. Black walnut is usually planted as a standalone specimen due to the toxicity of falling fruits that can harm other plants, but trees like the sugar maple and flowering dogwood work well with it.

Symbolism

Health, Mental powers, Infertility, intelligence, focus, clarity of thought

Interesting Facts

Although the nut of the black walnut is tasty, it is exceptionally difficult to extract. There are unusually elaborate huskers, such as one that uses a car tire rotating against metal. The common DIY method includes trampling and rolling the nut with your shoe against a concrete surface, but even breaking the nut doesn't always promise smooth extraction of the kernel.

Name Story

Black walnut: Walnut is actually derived from "walhnutu" from the Anglo-Saxon language meaning "foreign nut", as the nut originated from Italy and Gaul. Juglans nigra is called black walnut to differentiate itself from the indigenous nut, hazelnut. Also, its tree bark is greyish-black in color and its wood is dark-colored by nature. Hence, it is called the black walnut.

Get quick plant knowledge with a snap

Snap a photo for instant plant identification and learn about its name, symbolism, interesting facts, uses, and more.

Download the App for Free

Toxicity

Black walnut is a tree with toxic properties that affect humans, cats, and dogs. The most toxic part is the husks of fruits. Symptoms in humans include skin irritation; ingestion causes negative reactions. Cats suffer from physical discomfort and illness, dogs show panting, restlessness, and tremors. Immediate veterinary care is crucial for pets exposed to black walnut.

Identify toxic plants in your garden

Find out what’s toxic and what’s safe for humans and pets.

Download the App for Free

Quickly Identify Black walnut

Compound leaves with 15-23 finely toothed leaflets, 2-4 inches (5-10 cm) long.

Dark grey to black bark with deep furrows and diamond-patterned ridges.

Large round fruits, 1-2 inches (2.5-5 cm) in diameter, with green husks turning black.

Catkin flowers measuring 2½ to 5½ inches (6 to 14 cm), yellow-green in color.

Trunk with rough, deeply furrowed dark brown bark featuring diamond-shaped patterns.

Identify plants with a snap

Instantly identify plants with AI: Snap a photo, and get accurate results within seconds.

Download the App for Free

Care Guide for Black walnut

Every 1-2 weeks

Water

Full sun

Sunlight

5 - 35 ℃

Ideal Temperature

Water: Thriving in hardwood forests, black walnut prefers well-drained soils with moderate moisture. It tolerates temporary dry spells but favors consistent humidity. Water black walnut every 1-2 weeks, ensuring hydration without over-saturation, as soil moisture is crucial during its active growing season.

Fertilize: For black walnut, apply a balanced fertilizer in spring and high nitrogen during early growth. Reduce fertilization in fall to prevent frost-sensitive growth. Use granular types at the drip line and water thoroughly afterward. Young black walnut needs frequent feedings, while mature black walnut requires less, complemented by organic matter.

Pruning: Black walnut, valued for its timber, benefits from early spring pruning. Remove dead/diseased branches and thin crowded limbs for better airflow. Cut outside the branch collar for quick healing. Regular pruning enhances health, productivity, and size control, ensuring black walnut's vitality and maximized yield.

Propagation: Black walnut is valued for its timber and nuts. Propagation primarily occurs via seeds for genetic diversity. Softwood cuttings can root in high humidity, while grafting onto rootstocks combines desirable traits. Use healthy parent trees for cuttings, treating them with rooting hormone to aid root development.

Get tips and tricks for your plants.

Keep your plants happy and healthy with our guide to watering, lighting, feeding and more.

Download the App for Free

Images of Black walnut

Attributes of Black walnut

Distribution of Black walnut

Culture

Toxicity

Quickly Identify Black walnut

Care Guide for Black walnut

PEOPLE ALSO ASK

Common Pests & Diseases