Food Crops Grown Under Cover

Mushrooms are by far the largest segment of crops grown under cover. According to the U.S. Department of Agriculture (USDA), U.S. production of mushrooms remained relatively stable during the first decade of the 2000s. In 2009, 285 growers produced 817 million pounds of the crop, up 1 percent from the year before. Total value of sales declined 1 percent to $957 million, with 85 percent of sales attributed to fresh mushrooms and 15 percent to those used in processing foods. The average price per pound also remained fairly stable, decreasing only 1 cent to $1.17. Factors influencing the industry included business consolidation and rising production costs, particularly for compost, which is the most important input necessary for mushroom production. The first and second decade of the twenty-first century also saw an increased demand for specialty varieties as well as an increase in organic production.

The Agaricus variety of mushroom accounted for 95 percent of total mushroom sales in the United States in 2009. Shiitake, oyster, and other specialty mushrooms accounted for the remaining 5 percent. More than 60 percent of mushrooms grown in the United States come from Pennsylvania. About 15 percent are grown in California, and other states account for the remainder.

In the first decade of the 2000s, U.S. imports of mushrooms increased, reaching 247 million pounds in 2007. About 71 percent of the mushroom imports were used in processed foods. Export figures were much smaller, with 29 million pounds sent overseas in 2007. In addition, consumers increasingly preferred organic mushrooms. In 2001, sales of processed mushrooms declined 18 percent, reaching their lowest level in 30 years. In contrast, fresh mushroom sales, particularly of Agaricus mushrooms, continued to climb. Fresh Agaricus mushroom sales totaled 678.7 million pounds in 2009. Production efficiency allowed growers to harvest about 5.75 pounds per square foot.

The top two companies in the industry in the early twenty-first century were Monterey Mushrooms, Inc. of Santa Cruz, California, with $160 million in sales and 3,000 employees, and Vlasic Farms, Inc. of Blandon, Pennsylvania, with $150 million in sales.

Early in 1993, the National Mushroom Research and Promotion Act was passed. Under the act, producers and importers of fresh mushrooms with sales of at least 500,000 pounds can be assessed up to 1 cent per pound by the Mushroom Council to be used in generic promotion and research. Other legislation passed in the first decade of the 2000s sought to encourage U.S. consumption of domestically grown fruits and vegetables, including mushrooms. These included the Specialty Crop Competitiveness Act of 2004 and the Food, Conservation, and Energy Act of 2008.