Walnut Trees of North America

Translated as “Jupiter’s Nut” the walnut tree genus is known as Juglans and belongs to a group of plants including pecans and hickories classified as the Juglandaceae family. This is a type of spruce tree that produces a nut known as a drupe. This is so since the hardened inside shell protecting the seed is surrounded by an outer fleshy skin. Walnut trees are usually chosen to be planted in areas where there are hardiness zones as recommended by the U.S Department of Agriculture. The trees are planted in groves or groups and are cultivated for nut production. Guideline for cultivation takes into consideration the expected heights of trees selected to maximize recommendations for sun exposure.

The walnut tress contains both male and female flowers and are referred to as monoecious, which allows the plant to self-pollinate. They are known to be toxic to many plants, and so it is recommended to select special areas for planting to ensure only certain plants are grown around them. The chemical/toxins produced by the plant is known as juglone which produces an effect known as allelopathy; this is a genetic adaptation to keep vegetation from growing around the area near the base of the walnut plant.

Although there are several varieties of walnut that are grown in different areas of America, the ones grown in New York State is mostly the Black Walnut (Juglans nigra) and are cultivated for their distinct taste. Known as the American walnut or the eastern black walnut, the trees are developed and grown for the wood which is hard and attractive when displayed in woodwork items. The black walnut displays a rigid bark that appears in the shapes of diamonds with an extended trunk reaching high into the first set of branches. The foliage is usually dense with leaves shaping like a spear and reaching up to 24 inches in length possessing 12 to 24 lance-shaped leaflets.

Native to Eastern U.S the plant is classified in USDA Zones 4 to 9 and grows to heights of 50 to 150 feet with growing requirements of full exposure to sun. The trees are considered a natural resource for the area of Duchess County as it is essential for preserving the ecosystem.

Walnuts are the last trees to come into leaf, usually in May and are ready for harvesting at or near the end of September through the month of November.

Nuts are known to be a source of excellent food supply and they are seemingly effortless to grow even in cold climates. They are considered shade trees as a core feature of landscaping and are prized not only for the nuts but also for the wood. It is recommended for trees to be pruned every few years to maintain their value. If needed, seek professional help or advice for tree care. As the season of harvesting progress (September to November) the leaves of the tree, like most nut trees in the northeast will turn a pale green then to lighter yellow before they are shed for the winter.