This spring cover crop is an explosion of purple and yellow as
mustard and pea vetch enjoy the soft rains and early warmth.
Driving through wine country in the spring, you may see grass
and clover growing between the vineyard rows. Weeds? Maybe, but
more likely what you are seeing is a cover crop. Many cover
crops are annually reseeding grasses or clovers. These are
generally mown 1-3 times throughout the spring and the green
thatch is left on the ground as a natural mulch and nutrient
base for soil organisms. In late spring or early summer, the
crop is allowed to set some seed, and then the whole crop is
plowed under so that it doesn't compete with the vines during
the dry summer months. Some vineyards, particularly those with
erosion problems, may use perennial grasses which form a thick
sward that holds the soil in place, and also provides traction
for farm equipment in wet weather. Many vineyards utilize a
'natural mix' cover crop of rye, barley, clover, pea vetch,and
mustard. This ensures that no matter