With panicked shoppers cleaning out stores, and basic foods like dried beans and potatoes becoming increasingly difficult to track down, even those with no gardening experience are searching for do-it-yourself YouTube videos on how to build a raised bed.

On the first day of spring, home gardeners planted seeds and saplings. Savvy nurseries rushed to get their inventories online so shoppers could pay in advance and make contactless, curbside pickups. Bags of potting soil sold out. Corn, sorghum, squash, kale and cabbage seeds moved fast.

“Like every seed company, we’ve had a huge uptick in sales,” said Nate Kleinman, who lives and farms in southern New Jersey (where nurseries and farming supply stores have been classed as essential businesses).

“People seem to be preparing for some serious disruptions in the food supply. I’m not alone in feeling concerned with how this may go down,” he said.

Mr. Kleinman co-founded the Experimental Farm Network in 2013, a nonprofit in Philadelphia, that connects amateur farmers, gardeners, plant breeders and researchers, and also sells organic seeds.

When Mr. Kleinman put up a call on his social media for planting “Corona Victory Gardens,” alongside an image of Superman, Batman and Robin gardening on the cover of a 1943 issue of “World’s Finest Comics,” he heard back almost immediately from 1,000 eager gardeners. The majority of them were amateurs, looking for seeds, lumber to build raised beds and basic information about soil and how to grow food, he said.

“The war-garden model was inspiring for a lot of people, because there were all these huge forces at work around the globe that were out of their control,” Mr. Kleinman said. But he added that the term “victory garden” makes some modern farmers cringe because of its military connotations, and its use during the internment of Japanese-Americans, many of whom were farmers themselves.