#5: Cover Crops and Weeds. Journey to Harvest…and Beyond!
What is a “cover crop”?
As conscientious Stewards of the Land, we try to be as earth-friendly as possible, but NOTHING in farming (or life) is perfect…so we simply weigh the pros and cons with every decision and try to make the BEST possible “sustainable” choice for the environment, for our crop, for our health and for the health of the land. Part of that “sustainability” plan in our vineyards is to plant a cover crop of selected beneficial plants in the vineyard between the rows of grapevines.
Why is a cover crop “sustainable”?
A cover crop planted between the vineyard rows will hold the soil together and reduce the possibility of erosion. It will also help choke out unwanted weeds and will supply valuable nutrients to the soil. That’s being sustainable!
How do you maintain a “cover crop”?
Some farmers choose to not plant any cover crop between the vineyard rows (usually because the ground is flat with little chance of erosion), some will tractor-disk (roto-till) each row every year and then re-seed the cover crop, some will disk only the alternate rows and then re-seed, and some vineyards choose to let that cover crop continue un-mowed. (Drive around and look!) There are, again, choices, but most winegrape farmers believe a cover crop of some kind is a good idea.
What about all that pretty mustard you see all over the Wine Country? Is that a good cover crop?
Napa takes great pride in their “Mustard Festival” each year, but (as in everything else) using mustard as a cover crop is a choice, so we weigh the pros and cons. Mustard may be very pretty, but if the plants grows 3’ tall, they will also have a 3’ root system. And where do those long mustard roots travel? The roots travel as fast as they can, right to the emitters, robbing both water and nutrients from the grapevine. (It’s called “Hydrotropism”and the most stunted grapevines in any vineyard are those vines that are close to any surrounding oak trees that have sent their roots out searching for water.) So, is mustard good for grapevines? Depends who you talk to, but methinks not.
Do farmers have to maintain their cover crop?
Both our vineyards here at GlenLyon are hillside and we are very concerned with erosion, so disking the vineyard rows wouldn’t be the best idea for us. Instead, we have a permanent cover crop of four mixed beneficial seeds: two clovers, a fescue and a brome. These low-profile plants re-seed the soil and then grow back beautifully each year after the rains begin. Our cover crop is low-growing, it’s nice and green, attracts beneficial insects, and we have no erosion. (We also mow that low-lying cover crop twice, the last time during early Spring to keep any possible freezing air flowing (cool air is low and warm air rises) to reduce the chance of a Spring frost that can damage new grapevine green tissue growth. The timing of those mows is important so that the plants will re-seed themselves for the following season.)
What about weeds?
“A Weed by any Other Name, is still a Weed” (almost) ROMEO & JULIET by Wm Shakespeare
A “weed” is simply a plant that is growing in the wrong location. Any weed that is provided by Mother Nature (or an overzealous cover crop spill over) that is growing underneath our drip emitters competing for water and nutrients now becomes a weed. It is unwanted and should be removed.
How do you get rid of those unwanted weeds?
Early this Spring, we invested in a (very costly) Italian-made tractor-bolt-on unit made by Rinieri. (see below, then Google it to see the video!) It is called an “Bio-Dynamic Under-Vine Cultivator” and we are in love with it! (It was also Wife-Suzy’s combination Birthday, Mother’s Day & Christmas gift!) As we drive the tractor up and down the vineyard rows, roto-tilling the soil 8” on each side of the vines to a depth of 2”, eliminating both the weeds and the root systems, but never touching the grape vines. Since our upper vineyard soil has not been disturbed since we originally deep-ripped the ground over two decades ago before planting those vines, the ground has grown pretty hard, so we are finding that the machine needs two passes on each row. There is a lot of churned up rock removal after tilling, so I figure it will take us three full seasons until the vineyard is perfect, but (as our eco-friendly obsessed daughter says) “It’s much better than using RoundUp, Dad!”
So there you go. (C’mon by and I’ll show you how Wife-Suzy’s new early-Birthday, Mother’s Day & Christmas gift works!)
Squire Fridell, GlenLyon Vineyards & Winery
“Just Drink It!”