DENAIR, Calif. — The last time Wendell Naraghi tried to make money from organic nuts, in the 1980s, he failed miserably.

“Basically, we stopped because no one paid me,” said Mr. Naraghi, whose father started the family’s large nut orchards here in the Central Valley in the 1940s. “There just was no market premium for organic.”

Today, the problem is turned upside down: Companies can’t get enough organic ingredients to satisfy consumer desire for organic and nongenetically modified foods. The demand for those crops outstrips the supply, leaving farmers like Mr. Naraghi racing to convert their land to organic production, an arduous and expensive process.

“Customers are asking for it,” said Mr. Naraghi, who is in the process of transitioning 300 of his 3,000 acres of orchards this year. “And we listen to our customers.”

The clamor for organic crops is so intense that major food brands, like General Mills, Kellogg and Ardent Mills, are helping to underwrite the switch. General Mills, for instance, recently signed a deal to help convert about 3,000 acres to organic production of alfalfa and other animal feeds. Ardent offers farmers a premium for crops grown on land while a farm transitions to organic.