As winter winds down and signs of spring start to pop up, one of our favorite things to see in the Napa Valley is the burst of yellow that blooms throughout and blankets the vineyards. While these pretty plants are pleasing to the eye, their purpose goes beyond aesthetics. But just what are those beautiful blossoms that seem to pop up overnight? Mustard plants! Probably not the eloquent name you were expecting for such an eye-catching and beneficial plant, but that’s exactly what it is. While it may not qualify for one of the Seven Wonders of the World, it’s a true wonder in wine country not to be missed.
MUSTARD TAKES ROOT IN THE NAPA VALLEY
Mustard is not native to the Napa Valley and there are some legends out there as to how it first made its way to the New World wine country. In the early 1800’s, while Spanish and Mexican explorers were discovering California and looking for suitable mission sites, missionaries would carry sacks of mustard seed on their backs, and the sacks had a small hole that would allow the seed to sprinkle out as they walked. The blossoming of the mustard plant served as a marker of already explored territory. On the lighter side, one legend claims that a Franciscan priest loved the condiment so much that he spread the seed everywhere he went.
MORE THAN A CONDIMENT
While the mustard plants in the vineyards are not the kind used to make the tasty condiment to liven up hotdogs and hamburgers, it has a variety of purposes and benefits to the vineyards it blankets.
Natural Pest Repellant – Mustard (genus Brassica) is related to other cruciferous vegetables and cabbages. Brassica species include broccoli, cauliflower, cabbage and turnips. These plants contain very high levels of glucosinolates. These compounds, in the presence of water, create a natural fumigant that prevents nematodes (microscopic worms that can damage vines).
Nutrient Rich Mulch – Like many species in the Brasscia genus, mustard is a nutrient rich plant. When the buds start to appear on the vines, the mustard plants are plowed under to create an organic mulch that is rich nutrients and phosphorous which help replenish the soil and help the vines thrive.
Natural Erosion & Irrigation Control – From November through April, California usually sees the heaviest rainfall of the year. The fast growing mustard plants start popping up in January and create a cover crop that helps draw down the abundant moisture in the soil, and prevents the soil from eroding and washing away during extremely heavy periods of rain. In addition to erosion control, the mustard plants help with irrigation and create well-drained soil for the grapes to thrive between bloom and veraison. The large deep roots grow well past the cultivation depth. When they decay into the soil, pathways are created for the rain water and nutrients to go deep into the ground. Where Mustard grows, you have healthy soil and happy vines. Without this natural erosion control and irrigation, vines with shallow roots may be washed away and too much water in the soil will lessen the quality of the grapes.
WHERE THE WILD MUSTARD GROWS
Mustard plants grow especially well in the Napa and Sonoma regions of California. The soil and topography in those areas are ideal for mustard plants to take root and thrive. While mustard plants can be found in other wine growing regions, it is best suited, and most beneficial, to the soil of the Napa Valley. You will also find it in the flat area of Vineyard 1869 along Steiner Road.
WONDERING WHEN TO SEE THIS WONDER?
The mustard plants usually start to pop up in the Napa Valley sometime in January. Come mid-February, they are in full bloom and the Napa Valley is an ocean of yellow for as far as the eye can see. They continue to thrive well into March, but once bud break happens, usually sometime in early April, the plants are tilled under for their nutrients. For years, the mustard plant was seen only for its benefits to the vines and soil. Today, the plants are celebrated for both their beauty and their benefits.
Recipe - Mustard Seed Crusted Prime Rib Roast