Attributes:
The practical and the aethetic combine in black walnut to make this species one of the most treasured trees in American history. The valuable dark brown wood is strong with a handsome grain that polishes easily and gleams
forever. The rich flavored nuts are enjoyed fresh and retain their flavor and texture during cooking. Black walnuts have nearly twice the protein of English
walnuts.
Description:
When grown in the open, the black walnut reaches 75' tall with a round, low branching, open crown that spreads nearly as wide as it is tall. In forests and plantations, the tree may reach 150' tall with a well formed trunk and lower limbs self pruned from « to 2/3 the distance from
the ground. It develops a deep taproot and is difficult to transplant. The hard
to crack shell encases a rich flavored nut. However, the crushed black walnut
shells can stain fingers, clothing, and concrete. The trees bear in 12-15
years. (Partally self-fertile, plant multiple trees to ensure pollination) (zones 4-9)
Alleopathy is the term given to the suppression of growth of one plant species
by another due to the release of toxic substances. Black walnut tree roots
contain juglone, a toxic substance released when the the roots of other juglone-sensitive species come in contact with walnut roots. You must keep a wide separation between the black walnut tree and susceptible plants. A partial list includes tomatoes, potatoes, peas, peppers, cabbage, alfalfa, serviceberry, chestnut, pine, arborvitae, apples, blueberry, blackberry, cherry, azalea, rhododendron, lilac, hydrangea, privet, members of the heath family. The black walnut's poison does not work on all species and some even seem
to thrive on it.
Wildlife Value:
The nuts are eaten by woodpeckers, foxes, and squirrels.
History/Lore/Use:
This native tree has been called our best friend in times of war and peace. Native Americans and early settlers used it for food, dyes, ink, medicine, fence posts, gun stocks, and furniture. Today black walnut wood is highly prized for paneling and furniture and the nuts for food.
Leaves:
Pinnately compound, alternate, 12"-24" leaves each consisting of 15-23, 2"-5" dark green leaflets. The leaflets are finely toothed.
Flower Color:
Greenish
Bloom Time:
Spring.
Fruit Description:
The fruit consists of three layers: the round 1 1/2"-2" green fleshy husk borne singly or in clusters of 2-3, a black, hard, thick
corrugated, 1-1 1/2" shell, a kernel with a rich, oily flavor. Walnut trees produce nuts in 12-15 years. They are harvested in early autumn.