Cover crops in the vineyards
It is cover crop time in the wine country. During the late Fall and into the Winter, the vines drop their leaves and the rain falls. Now is the time to observe the variety of cover crops growing between the vines in vineyards throughout California’s wine regions. What are cover crops in the vineyards and why are they used? Cover crops are planted for a variety of reasons, but essentially these cover crops help replenish the soil depleted during the growing season. It is an alternative to the use of chemical fertilizers. Using certain cover crop plants increases the carbon and nitrogen in the soils. In the Napa Valley and Sonoma wine country, the mustard plant with its bright yellow flowers can be seen in many vineyards. The colors are spectacular. The mustard plant inhibits the presence of soil-borne pests. Cover crops also help offset erosion on hillside vineyards. After the vineyards are pruned and shortly before “Bud Break,” the cover plants will be plowed into the soil. This occurs in early March. When you tour a wine country in the winter months, it is easy to observe which vineyards practice organic or sustainable farming by the use of cover crops. If you don’t see any thick rows of cover crops, it is likely the vineyard manager or grower is using chemical fertilizers.