Harvest Time for Nuts

California exports walnuts to Europe, Canada and Japan.

Varieties of nuts grow around the world, and there is no uniform harvest time. Even in a single country like the United States, the variety of the nut and its growing location are constraints affecting harvest times. Rich in nutrients including protein, fiber and Vitamin E, nuts have been grown and consumed for thousands of years. Native North Americans used “nutting stones” as far back as 6000 B.C. to crack open shells, according to nut production company SunTree.

About Nuts

Because nuts are botanical seeds produced by trees and shrubs, they are commonly classified in conjunction with fruits. Unlike fruits, though, nuts are single seeds enclosed in hard husks. Nuts categorized as drupes, fruits with thin outer skins, soft middles and a hard stony seed casing, include almonds, walnuts, pecans, date palms, macadamias and pistachios. According to the United States Department of Agriculture, almonds, walnuts, and pecans are the preferred nuts of choice in the U.S. Despite its name, the peanut is a legume that grows in soil.

Nuts as Commodities

Large crop farms in California grow pistachios.

In the United States, nuts are common crops throughout the south and western states. California is the leader in nut production, exporting 100 percent of its harvested almonds, pistachios and walnuts to Canada, the European Union and Japan, according to See California. Pistachios grow in California, while Hawaii leads in the production of macadamia nuts; Georgia, Texas and Alabama also produce large crops of nuts commercially. Small nut crop farms are found throughout the United States with additional nut trees growing wild where climate, soil and water conditions allow. In New York State, for instance, black walnut trees grow wild in many yards. In Nebraska, wild trees commonly suffer from insect blight, producing inedible nuts.

Harvesting

Chestnuts are best suited for hand harvesting.

Growers harvesting just a few nuts for personal or family use generally wait for the nuts to drop naturally from the trees when they are ripe. Commercial growers, however, must gather them quickly in order to and process them for export. Depending on the type of nut, tree shakers and mechanical harvesters are used. Not all nuts are suited to mechanical picking. California chestnuts, for example, are harvested mainly by hand although there have been some attempts to use modified walnut sweepers to gather them.

Harvest Time

These pistachio trees will not be ripe for harvest until fall.

The only sure way to determine when a nut is ripe is when it falls to the ground. This method works well with wild trees, but is not reliable for crop farming. Growers determine when mature trees are ready to harvest based on the planting zone the crops are in. Zones are classified by the U.S. Department of Agriculture based on plant hardiness and minimum temperature ranges; there are 20 zones in the U.S. In New York, black walnuts reach their full size in August and ripen between late September and early October. California chestnuts are harvested during a two-week period in October. Because of its microclimate, macadamia nuts in Hawaii are harvested year-round.

References

• SunTree: Mixed Nuts: History
• Wayne's Word: Identification Of Major Fruit Types
• U.S. Department of Agriculture: Fruit and Tree Nuts: Overview
• The Peanut Institute: Peanut Facts
• See California: California’s Top 10 Agricultural Counties
• Oracle ThinkQuest Education Foundation: Nuts
• New York Nut Growers Association: Basic Cultural Information
• University of Nebraska–Lincoln Extension Lancaster County: Nuts: Harvesting and Storing
• Society of Ontario Nut Growers: Harvesting Nuts
• Agriculture and Natural Resources, University of California: Chestnut Fact Sheet

Resources

• The United States National Arboretum: Hardiness Zones
• Mac's Nut Co. of Hawaii: Home