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

Brilliant yellow and gold mustard is carpeting Northern California’s wine country. The plants signal the start of spring and the celebration of all flavors sharp and mustardy in Napa and Sonoma counties. The plants are not just pretty to look at. They also work hard to protect world-famous vineyards. The plants contain high levels of biofumigants and suppress the growth of microscopic worms that can damage vines. But not everyone loves mustard, which are not native to California. They grow aggressively that they smother native flora such as blue lupine and poppies. Winemakers say they have made the plant work for them.