Spectacular fields of yellow mustard draw visitors to Northern California's wine country

NAPA COUNTY, Calif. (AP) — Brilliant yellow and gold mustard is carpeting Northern California's wine country, signaling the start of spring and the celebration of all flavors sharp and mustardy.

Mustard isn't just pretty to look at. The plants, which bloom through March, are doing hard work to protect world-famous vineyards in Napa and Sonoma counties.

Mustard contains high levels of biofumigants, which suppresses the growth of microscopic worms that can damage vines, according to Sonoma County's tourism website. It also provides nutrients to emerging grape plants and keeps hillside soil in place to help fight erosion.

Not everyone is a fan of mustard, however.