Washington State's Skagit Valley is sometimes called the Holland of America. In mid-April every year, thousands of people come from all over North America to see the brightly colored red, yellow, and orange fields of tulips that cover hundreds of acres, sometimes as far as the eye can see.

One of the earliest crops that thrive alongside the tulip fields in the Skagit Valley is equally brilliant in color. Just as the tulips are fading away a flower of intensely bright yellow bursts forth in the fields. This is the mustard plant, with its almost iridescent bloom, looking just as shockingly yellow as the stuff we squeeze out onto our summer hot dogs.

As well as being a welcome burst of early spring color and a tangy condiment, mustard has long been valued for its medicinal properties. The pung…