Gregg Hutson’s shady backyard would be a wet blanket for most gardeners. Not for Mr. Hutson, who grows mushrooms at his home in Takoma Park, Md. “It’s pretty spongy,” says the 43-year old advertising agency copywriter, stepping around some chanterelles. “Great mushroom-growing conditions.”
Mushrooms—the ones intended for culinary purposes—are in. More than 400 food products featuring mushrooms were introduced in 2017, up 22% from a year earlier, according to Innova Market Insights. The rise of the mushroom comes as more...