February 8, 2021
By Bruce Neyers
The first of the new cover crop emerges in the Left Bank Merlot Vineyard in December.
We’ve had some cold weather here in the Napa Valley over the past few weeks, but we finished out December with warm, sunny days, and enough rain to get our cover crop started. For sustainable grape growers like us, every new vintage begins by deciding the composition of the cover crop, and the preparation of a corresponding seed mix. I just received the following note from our vineyard manager Hugo Maldonado:
We planted a legume based cover crop this year. It works as a soil builder, and helps re-place nitrogen, while adding organic matter to the soil. It’s a combination of vetch, beans, peas, clover and oats. It will grow to a height of two-three feet in the winter, then we will mow it in the spring, let it decompose for a few weeks, then till it into the soil with the tractor disc.
The ideas behind our sustainable farming decisions were originally the work of the late – and justifiably famous – Amigo Bob Cantisano, who would do a petiole analysis after every growing season, analyze it for depleted elements and minerals, then seed the vineyards with the plants capable of replacing what the vines removed. Each year, we naturally replace what’s used during the growing season without using artificial fertilizers.
Going back through my records, I found a memo Amigo Bob sent us after the 2010 harvest, explaining the following year’s cover crop:
We’ll plant 3 kinds of vetch. All are legumes, and add nitrogen to the soil. Having three varieties insures we get a good stand of vetch. Some years, one of the varieties may not germinate or grow well due to cold, drought, frost or heavy rain. The three types bloom and mature at different times, so if we need to incorporate them early due to a drought, or late due to heavy rains, we still get at least one to take. They are also great sources of nectar and pollen for beneficial insects and honeybees.
The peas are chosen because they have good biomass, add nitrogen, and attract a wide variety of beneficial insects, both during the winter and again when they bloom in the spring. I listed both Magness and BioMaster peas because in some years one type or the other is hard to get. I will have both varieties in the mix.
The Cayuse oats are chosen for their quick developing root system that gives early-season erosion protection. They have deep, fibrous roots that really improve the soil texture and water infiltration. Also the oats act as a ‘ladder’ to give the vetch and peas, which are ‘viney’ growers, a way to climb up on the oats and get more sun. Also, oats succeed in even the driest year, and tolerate ‘wet feet’ in spring. Cayuse oats are chosen because they are the last variety of oats to go to seed, thus avoiding any risk of them becoming a weed in future years. They have a lot of pollen in their blooms, so they feed numerous beneficial insects.
For us at Neyers Vineyards, being good grape growers involves being sensitive stewards of the land as well. Our Left Bank Red does an extraordinary job of showing the long-term benefits of conscientiously applied, sustainable farming practices. Try a bottle of this classic blend of Merlot and Cabernet Sauvignon, and see if you agree with us.
The Left Bank Red Merlot vineyard in late January. The growth of the oats is especially obvious, and the other plants are climbing along with them. The leaves have all dropped off now as the vines enter dormancy. We will begin to prune in a few weeks.