Black Walnut and Butternut

By The Old House Web

Black Walnut and Butternut

Black walnut and butternut trees grow best in deep, fertile, moist soil. If trees are grown for nuts, look for and buy grafted trees of superior varieties. Avoid dry, infertile sites.

The roots of black walnut trees contain a chemical called juglone. The juglone kills the roots of other plants when the two root systems touch. The roots of a black walnut extend far beyond the branches so can affect a large area. Do not plant this tree close to desirable plants that may be injured as the two root systems grow together.


Plant bare root trees in the spring. Dig a hole large enough to hold the entire root system spread out in a natural manner. Do not allow the roots to dry out during planting. Do not fertilize the first year after planting but do apply a thick mulch of hay or straw. Water each time the soil is dry through the first summer but gradually reduce watering in late August and September.


Newly planted trees are given 1 1/2 pounds of 12-12-12 or and equivalent fertilizer. The rate is increased by 1 1/2 pounds each year until 1 to 2 pounds of actual nitrogen is being applied per 1000 square feet.

Mature nut trees need about 1 to 2 pounds of actual nitrogen per 1000 square feet per year. This can be supplied by applying a lawn fertilizer or a garden fertilizer such as 12-12-12. An alternative method is to apply 5 to 6 pounds of 12-12-12 or an equivalent fertilizer per inch of trunk diameter. Check to make sure the recommended rate of of 1 to 2 pounds of actual nitrogen is being applied.


Head back branches that are too long and prune off lower branches to aid lawn mowing. Stems that form a sharp angle with the main stem should be removed as soon as possible. The tight V crotch formed by such branches is weak and susceptible to splitting.

Rodent Control

Young trees are injured by the feeding of rodents. Rodent guards can be purchased from nurseries or mail order nurseries. Rodent guards may be made from quarter inch mesh hardware cloth. The guard must extend high enough up the tree so rodents can't stand on the snow cover and feed the trunk. Such protection should only be needed for 5 to 7 years.


Black walnuts or butternuts are ready for harvest when the hull can be dented by pushing on it with a thumb. Once the nuts are shaken off the tree, they must be removed from the hulls. If not removed quickly the nuts will be discolored and have an off flavor. Hulling may be done with a hand cranked corn sheller. After hulling, wash the nuts in a tub of water and place them in a cool, shaded, dry area to dry. The drying area should have good air circulation.

Crack a few nuts to see if they have dried properly. If the kernels are crisp, nuts are ready for cracking. Soaking walnuts and butternut in water overnight makes cracking easier but the moist kernels must be dried before being stored. Nut meats must be stored at temperatures below 40 degrees F to keep them from becoming rancid.

Go To Top of File               Main Page for this Data Base

Search Improvement Project