A few days ago, while walking a row of our parcel of baby Mourvèdre I couldn’t resist taking this picture. It shows how exceedingly well our September cover crop seeding has taken off. The intelligent use of cover crops not only respects our appellation’s engagement to ensure ecological diversity in our vineyards: the mixture of seedlings we used, including the sainfoin (a type of sweetvetch) in bloom in the photo, has many benefits for the environment, our vineyards and the quality of our wines.
I’m just beginning to understand why sainfoin got its name (“Saint Hay”)! This forage plant has many interesting attributes. A perennial legume with flowers arranged in tight, elongated clusters, it has a deep taproot (image A) that is a trusty ally for our vineyards’ soil. The root structure keeps the ground loose, aerates the soil, adds micro bacterial life and is very efficient at keeping weeds such as thistles and bindweed at bay.
During its growth spurt and flowering period in the spring, Sainfoin also consumes excess water. Its thirst abates significantly as of late May (the beginning of the dry period) and so it doesn’t compete with our vines during periods of hydric stress.
Better yet, sainfoin and other legumes store nitrogen captured from the air through their leaves to their roots in small nodules (the white bumps seen on the roots in image B). When mown (photo C) and especially when tilled, the sainfoin releases the nitrogen (an important element for growth) into the ground and thus to our vines, which allows us to avoid the use of exogenous fertilizer (manure for example).
Finally, the cover crop offers extra support and traction for our tractors after heavy rains and thus allows us to act quickly to prevent disease rather than cure it!
Best of all, the flowers of sainfoin are a favorite for pollinating insects since they offer them everything they need to make their honey. We’ve also discovered recently that the flowers are edible … a new dining experience awaits us!