When Is a Walnut Ripe to Pick on a Tree?

Ripeness

• Walnuts are generally ready to harvest by the middle of September. The nuts are ready to pick when the outer husks start to crack open and nuts often fall to the ground. Depending on cultivar, this can occur between early September and early November. Once nuts are ripe, shake the tree to help nuts fall as long as the bark is not damaged in the process. It takes multiple picking from a tree to harvest all the nuts that mature at intervals.

Collection

• Once the nuts have fallen, it is important to gather them as soon as possible as the nuts become prone to pest infestation, discoloration or mold. Avoid leaving undried nuts in sacks for prolonged periods of time at the heat causes mold. If the nuts fall before the hulls have cracked, let the hulls ripen on the ground for a couple of weeks until the hulls become loose. It is best to use gloves when handling walnuts as the hulls contains compounds that may irritate sensitive skin.

Drying

• Walnuts need to be dried before eating or storage. It is recommended to start drying with or without the shells 24 hours from harvest time. Drying shelled nuts requires less heat. Place nuts on trays with screen bases for optimal air circulation and place in 95- to 105-degree Fahrenheit areas. Avoid temperatures over 110 degrees as this will affect nut quality. Warm air over furnaces and radiator are also good for drying as long as temperatures remain below 105 degrees. Drying in conventional ovens is not recommended. Drying time increases at lower temperature. Walnuts are dried when nuts break in two with a snap and are not rubbery.

Fruit Production

• The tree starts to produce nuts after five to six years of planting and produces nearly 2.5 tons of nuts in seven to eight years. Single trees produce considerably less nuts. If walnut trees are planted primarily for the nuts, it is recommended to plant several trees with 30 to 50 feet between trees for healthy cross pollination and heavier fruit set. Black walnut trees impede the growth of many plants including sweet gum, azaleas, maple and apple around its perimeter as they produce a natural toxin in soil.