We are glad you asked. About ninety days after the last of fall rains mustard plants push through the dormant vineyard floors and adorn our beautiful valley with one of the most seductive visual displays ever. Mustard crops serve as a biofumigator by suppressing various soil-borne pests and diseases through naturally occurring compounds. In short, by planting mustard vineyards in Napa are doing their part to remain sustainable and bring to your table the purest of wines.
According to Cornell University:
“Brassicas such as cabbage, kale, cauliflower, brussel sprouts, broccoli, mustard, and turnips naturally produce glucosinolates, the compounds that make certain brassicas “hot”. Brassicas sold as cover crops have been identified or specifically developed to contain very high levels of these glucosinolates. The higher the levels of glucosinolates present, the better the biofumigant effect. The process works as so: when plant cells are damaged such as by chopping, glucosinolates are released and come in contact with an enzyme (myrosinase). In the presence of water, the reaction produces the natural gas isothiocyanate (ITC). ITC is responsible for the suppressive effects of the practice. ITC is similar to the active ingredient in Metham Sodium or the conventional fumigant Vapam (a.i. Methyl ITC). In addition to the soil biofumigation benefits, brassica cover crops are ideal for adding organic matter to the soil and improving many soil health related characteristics due to the large quantity of “green” or fresh biomass produced and incorporated into the system.”
In addition to the eco-agricultural benefits of Mustard cover crop one must not discount the grandeur of nature in terms of visual feedback. If you are fortunate enough to visit sleepy Napa during this time of the year not only will you get the opportunity to capture the most astounding of photographs where contrast and beauty dominate you also stand a good chance of visiting with renowned regional wine makers always willing to chat with wine aficionados looking for beautiful examples of oenology to add to their cellars.
We find great delight in hosting wine collectors and delivering the most luxurious and exclusive wine tours in Napa. Join us as we witness the beauty of nature slowly waking up to deliver our next vintage.