WEED MANAGEMENT TOOLKIT

Napa Green is the first sustainable winegrowing certification globally to require the phaseout of Roundup, and ultimately synthetic herbicides. When we looked for a roadmap and resources for going herbicide-free we didn’t find it all in one place, so we created this Weed Management Toolkit to support our Napa Green community and other perennial growers looking to cultivate healthier soils and regenerative farm systems.

Since Napa Green became an independent nonprofit in 2019, our goal has been to set the highest bar for sustainability and climate action in the wine industry. Our next-level Napa Green Vineyard program, launched in 2021, is unique in its whole-systems focus on: Social Justice, Regenerative Ag & Soil Health, Irrigation Efficiency, Forest Health, Climate-smart burning/alternatives, and Pesticides. 

While pesticide and herbicide use is just one element of a holistic approach to sustainable winegrowing and climate action leadership, this leadership matters to our families, our communities, and our customers. As a world-renowned winegrowing region, producing the premier agricultural product, we must leverage our powerful leadership platform to galvanize change locally and globally.  

Napa Green takes this bold stance for the health of the ecosystems and communities in which we farm, and for the health of the stewards whose careful management results in the finest wines in the world.

Message from Executive Director 

Case Studies: the how and costs of herbicide-free

Weed management tools

Clemens Weed Knife

Pros: Lower soil disturbance, no soil inversion. High ground speed. The frame can also support a ‘twister’ type mower for a pre-knife pass, or a french plow for deeper disturbance. Single- or double-sided.

Cons: Low level of disturbance means weeds can re-sprout depending on timing and soil moisture. Not great with heavy weed cover. Can either be one sided (lower efficency) or, on flat ground, can have a second side, but might require multiple passes.

Gramegna Power Harrow

Pros: Lower soil compaction than others. Effective in varying soil types. Can handle terraces. Head articulates to adjust for slope.

Cons: Single-sided, doesn’t do well with lots of rocks. Expensive and lots of maintenance required.

Calderoni Rotary Disk Harrow

Pros: Double-sided and efficient. Handles rocks well.

Cons: More compaction, especially on moist soil.

Pellenc Sunflower

Pros: Double-sided, lower number of passes. Limited soil disturbance.

Cons: Can cause soil compaction. Can require multiple passes due to lower termination efficacy.

Gearmore Spedovator

Pros: Low soil disturbance. Can handle tall weeds.

Cons:  Requires several passes: One to turn the soil/weeds and another to replace the soil on each side.

French Plow

Pros: Very effective at smothering weeds and preventing regrowth.

Cons:  Significant soil disturbance (inversion of the top layer). Possible compaction in wet soil. Long term use can displace topsoil. Single-sided.

Fischer TWISTER Mower

Pros: No soil disturbance. Fast groundspeed. Keeps living roots in the ground.

Cons: Does not kill herbaceous cover. Possible understory growth depending on timing.

Sheep

Pros: Ability to manage the entire vineyard floor, even steep, terraced, and tight rows, without fossil fuels. Increased nutrient cycling, as well as soil and vine health.

Cons: Require knowledgeable shepherds to be managed/rotated effectively. Small parcels are inefficient. Damage to vines and infrastructure is possible.

Organic (OMRI) Herbicides

Pros: Helpful as a foliar spray when the soil is too wet to cultivate. Reduces weed competition in unfavorable conditions

Cons: Organic herbicides do not match the effectiveness of synthetic herbicides, but are another tool in the weed management kit. They are ineffective once weeds have fully established root systems and can be expensive.

Note that feedback is assembled from members who have used these tools.

events and workshops

RISE Climate & Wine Symposium
The RISE Climate & Wine Symposium is a series of six half-day events organized around the Six Pillars of Sustainable Winegrowing Leadership. Join us in taking action.

Regenerative practices are a proactive approach to farm health. If you’re healthy enough you don’t get sick – you’re able to fight off pests and disease. It’s a paradigm shift.

We need to have a cultural shift in vineyard aesthetics. Is bare ground how we want to present our skill as farmers? Or cultivating life under our vines?

Regenerative farming starts with a mindset to build biological and human communities…On farm after farm the soil is naked, hungry, thirsty and running a fever.

The Napa Green Vineyard certification provides growers a beneficial roadmap for continual improvement. The process lead Dominus Estate to measure our environmental impact and, since we can only change what we measure, has strengthened our methods for interacting with our site's vital resources: soils, water, flora, fauna and people. Ultimately, this certification improves the grower's relationship to the land and deeply informs farming decisions.

You don’t hear more stories about how farmers eliminate herbicides because usually they just decide to do it, and they don’t look back. The decision is the hardest part.

Eliminating Roundup and other synthetic herbicides is a significant step towards more just, resilient agricultural communities and local ecosystems. A non-exhaustive list of the benefits: Farmworker health, Soil health, Ecosystem health, Community health, Consumer health, Consumer perception/Market demand, Visibility of Napa Valley and the wine industry.

resources

Napa Green VINEYARD

Not yet a Napa Green member? Learn more about our leading certification, including our boots-on-the-ground consulting services for regenerative farming, soil health, and irrigation efficiency. 

If you have any other suggestions for tools or resources please send them to vineyard@napagreen.org. Consider joining our Regenerative Viticulture google group, and Newsletter mailing list for regular updates.