Finding balance in the vineyard with cover crops
Planting our first block of Zweigelt at the home farm.
We planted the first two acres of grape vines at the home farm into untilled corn stubble before we even technically owned the farm. Although we had made an offer on it in September of 2020, the loan application process through the U.S. Department of Agriculture took until July of 2021 to close on the purchase.
Our good intentions of preparing the ground, helping the soil recover from years of corn and dealing with the weeds and invasive plants before that first planting had gone out the window. All summer and into fall, we tripped over corn stalks and watched the Queen Anne’s Lace grow chest high.
This spring, with a warranty deed in our hands and an order placed for eight more acres of vines to arrive in 2023, we’re focusing on soil. One of the big things we’re doing to prepare for next year’s planting and to help support healthy soil long term is seeding cover crops.
WHAT IS A COVER CROP?
A cover crop is a plant that is used to slow erosion, contribute nutrients, enhance water availability, smother weeds, help control pests and diseases, increase biodiversity and do a lot of other helpful things in the vineyard.
Different types of cover crops contribute or consume different nutrients and fulfill different roles. For example, clover is used to increase plant-available nitrogen in the soil. On the other hand, a radish, with its long roots, may be used to reduce soil compaction and make it easier for the subsequent crop to send its roots deeper. Different cover crops can be planted together to work in tandem too.
We unintentionally grew 30 acres of Queen Anne’s Lace in 2021. One of our goals is to outcompete the weeds with cover crops.
COVER CROPS CAN BE TEMPORARY OR PERMANENT
A temporary cover crop is usually planted to prepare a site for planting or in rotation with annual crops like corn. Depending on each farm’s specific goals, the temporary cover crop can be used to prevent erosion and carbon loss, improve soil compaction, increase microbial biodiversity, and improve nutrient cycling.
The temporary cover crop is either mowed to retain the plant roots in the ground or tilled in as a green manure which returns nutrients to the soil as the cover crop breaks down.
A permanent cover crop, as the name implies, coexists with the vineyard long-term. You frequently see a permanent cover crop in between vine rows, especially in areas where there is plenty of rainfall.
Permanent cover crops need to be durable and hardy so that the vineyard is passable with heavy equipment. We often see grasses filling this role. Permanent cover crops require ongoing maintenance such as mowing to keep the height low to allow for good airflow in the vineyard.
BALANCED COMPETITION
By adding another crop to the vineyard, we are inevitably creating competition for the nutrients and water in the soil. We need to be careful to encourage friendly competition between the vines and the cover crop.
We are looking for a balanced cover crop and vine environment that will increase organism diversity in the overall vineyard and outcompete weeds and invasive plants. “Balance” is such an easy sounding word, but it takes effort and practice. Like a gymnast jumping on a balance beam, finding balance takes effort, tiny shifts of weight and minor adjustments. Observation and adjustment are par for the course.
Beautiful Dutch clover cover crop at a private vineyard on Drummond Island. The soil at this vineyard site was depleted of nutrients and the vines were showing low vigor and nutrient deficiency. Over the course of three years, a combination of Dutch clover and organic chicken manure substantially helped with the soil and vine health.
FIGURING OUT THE RIGHT MIX
Before deciding on a cover crop we do extensive soil testing to understand the soil and its ability to retain moisture, as well as considering the grape varieties it will be growing alongside of.
And we don’t necessarily plant the same cover crop everywhere. Soil structure and composition can vary significantly throughout a vineyard so we want to customize our cover crop to the specific needs of each area of the vineyard.
As a visitor to a vineyard or winery that utilizes cover crops, this might look a little unusual! Instead of a neatly mowed lawn, you might see a mixture of grasses, flowers and vegetation that vary from area to area. We love asking our fellow grape growers and winemakers about the decisions they make in the vineyard and how they affect their wines – if you see something interesting or unusual in a vineyard, don’t be shy to ask the winery staff!
WHAT’S OUR GAMEPLAN?
This year at the home farm we are essentially seeding three different cover crops to fulfill three different roles:
Low-growing fescue grasses and a small percentage of white clover for under-vine maintenance and nutrient cycling
A mix of fescue grass and wildflowers to prevent erosion and increase diversity in the vine rows
Spring rye, fescue grass and clover to prepare the soil for our 2023 planting
We are also focusing on using as many native Michigan plants as possible in our cover crop mix. Native plants are well adapted at responding to the local climate. By incorporating them in the vineyard, we can help reestablish and preserve some of Michigan’s native flora.
While we have spent many hours researching our options, quite honestly, we’re not sure we have the right mix yet! You’ll find us in the vineyard, observing and adjusting, working towards finding the right balance. Be sure to follow along on Instagram and sign up for our e-newsletter below.
