Juglans Nigra
Contents
Description
Juglans Nigra, commonly known as black walnut, is a deciduous tree native to North America. It belongs to the walnut family, Juglandaceae, and is known for its dark, edible nuts. The tree can grow up to 100 feet tall and has a straight trunk with a wide, spreading crown. Its leaves are pinnately compound, with 11-23 leaflets. The bark is dark brown and deeply furrowed.
Taxonomic Information
| Domain | Eukarya |
|---|---|
| Kingdom | Plantae |
| Phylum | Spermatophyta |
| Class | Magnoliopsida |
| Order | Fagales |
| Family | Juglandaceae |
| Genus | Juglans |
Appearance
Black walnut trees have a distinctive appearance with their tall, straight trunks and wide, spreading crowns. The leaves are pinnately compound, with 11-23 leaflets that are lance-shaped and pointed. The leaflets are dark green and can grow up to 12 inches long. In the fall, the leaves turn a bright yellow before falling off. The bark is dark brown and deeply furrowed, with ridges that can resemble diamond shapes.
Care Guide
Juglans Nigra requires regular care to thrive. Here are some tips for caring for your black walnut tree:- Water: Black walnut trees require consistent moisture, especially during the first few years of growth. Water deeply once a week during dry spells.- Fertilization: Fertilize in the spring with a balanced fertilizer. Avoid using fertilizers high in nitrogen, as this can promote excessive foliage growth at the expense of nut production.- Soil: Black walnut trees prefer well-draining soil that is slightly acidic. If your soil is heavy clay or alkaline, amend with organic matter.- Sunlight: Black walnut trees prefer full sun, but can tolerate partial shade.- Hardiness Zones: Black walnut trees are hardy in zones 4-9.
Common Pests & Diseases
Black walnut trees are susceptible to a number of pests and diseases, including:- Walnut caterpillars: These pests can defoliate a tree if left unchecked.- Walnut weevils: These pests lay their eggs in developing nuts, causing them to drop prematurely.- Thousand cankers disease: This disease is caused by a fungus that attacks the bark of the tree, causing cankers and eventually killing the tree.- Walnut anthracnose: This fungal disease causes black spots on the leaves and can lead to defoliation if left untreated.
Habitat
Juglans Nigra is native to North America and can be found in a variety of habitats, including forests, woodlands, and riparian areas. It prefers moist, well-drained soils and can tolerate some flooding. Black walnut trees can be found in hardiness zones 4-9.
Question and Answer
Q: Are black walnuts edible?
A: Yes, black walnuts are edible and have a rich, nutty flavor.
Q: How long does it take for a black walnut tree to produce nuts?
A: Black walnut trees typically start producing nuts around 7-10 years of age, but may take up to 20 years to reach full production.
Q: Can black walnut trees be grown in containers?
A: No, black walnut trees require a deep root system and cannot be grown in containers.
Q: What is the difference between black walnuts and English walnuts?
A: Black walnuts have a thicker shell and a more intense, nutty flavor than English walnuts. English walnuts are also easier to crack and have a smoother texture.
Related Plants
– Juglans Regia (English walnut)- Juglans Cinerea (butternut)- Carya Illinoinensis (pecan)- Carya Glabra (pignut hickory)
References
– “Juglans Nigra Fact Sheet.” Missouri Botanical Garden. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=286496&isprofile=0&basic=juglans%20nigra- “Black Walnut.” University of Illinois Extension. https://extension.illinois.edu/treeselector/detail_plant.cfm?PlantID=222
