Best Practices for Abandoned and Neglected Vineyards

Abandoned or neglected vineyards are more than an eyesore—they are a serious agricultural and environmental threat to Napa Valley’s thriving winegrowing community. When left untended, these sites can become hotspots for pests and disease, putting neighboring vineyards and the region’s sustainability efforts at risk. As climate pressure, economic uncertainty, and shifting land use intensify, understanding the risks and responsibilities around vineyard neglect is more important than ever.
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1. What Counts as an Abandoned or Neglected Vineyard?
According to California law and agricultural best practices, a vineyard may be considered abandoned or neglected if:

• Vines are not pruned or maintained, often with excessive sucker growth.
• Mummified fruit remains on the vine from prior seasons.
• Trellis, irrigation, or frost protection systems are in disrepair.
• Brush, weeds, or invasive species overtake vineyard rows or headlands.
• Erosion control has failed, particularly on hillsides or sloped land.

Note: Vineyards slated for removal may temporarily resemble abandoned sites. Be sure to communicate with neighbors and the Agricultural Commissioner if delays occur due to weather or scheduling.

2. The Science: Why Abandonment Matters
Unchecked vineyards are breeding grounds for pathogens and pests that can spread quickly to nearby blocks—especially in a region like Napa Valley, where high-value crops are grown in close proximity.
Key pest and disease risks include:

• Trunk Diseases: Abandoned vineyards are a silent reservoir for trunk pathogens like Eutypa lata, Botryosphaeria, and Esca. These fungi infect through pruning wounds and remain viable for years in untreated wood.
• Insect Vectors: Pests such as leafhoppers, mealybugs, and sharpshooters can transmit devastating viruses like Grapevine Leafroll-associated Virus (GLRaV) and Pierce’s Disease. Overgrown vineyards offer ideal habitat for these vectors to breed and spread unchecked.
• Nematodes and Fanleaf Virus: Soilborne nematodes in neglected vineyards can host Grapevine Fanleaf Virus (GFLV), which leads to significant yield loss and is extremely difficult to eradicate once established.
• Rodents and Vertebrate Pests: Gophers, voles, and ground squirrels often thrive in unmanaged vineyards, damaging root systems and undermining adjacent vineyard infrastructure.
• Weeds and Invasives: Aggressive weed species can outcompete desirable cover crops, disrupt soil health, and interfere with mechanical operations. Some, like field bindweed and yellow starthistle, also harbor pests or become fire hazards.

3. What the Law Says
California’s Food and Agricultural Code Division 4, Section 5551, defines neglected or abandoned crops as a public nuisance when they:

• Harbor pests or disease.
• Pose a direct threat to agriculture in the region.
• Serve as hosts for quarantine pests or invasive species.

County Agricultural Commissioners have the authority to investigate, issue notices, and take abatement action if necessary. While compliance is typically pursued cooperatively, unresolved violations can result in significant legal and financial consequences.
Read the full statute here

4. What to Do if You Own a Neglected Vineyard
If you’re the owner of an underperforming or neglected site, it’s critical to act quickly to reduce pest pressure and protect your neighbors. Here are your options:

• Rehabilitate: If vines are still viable, consult with a PCA or viticulturist to restore vine health and resume production.
• Remove and Replant: Diseased or economically unviable vineyards should be professionally removed and replanted using clean plant material, following best practices for sanitation and erosion control.
• Lease or Partner: If you are unable to maintain the property yourself, consider leasing the land to a vineyard management company or local grower.
• Develop an IPM Plan: Use Integrated Pest Management (IPM) principles to control pests responsibly, minimize chemical inputs, and restore ecological balance.
• Get Expert Help: Reach out to the UC Cooperative Extension, a licensed Pest Control Adviser, or the Napa County Agricultural Commissioner for guidance.

5. What to Do if You Suspect a Vineyard Has Been Abandoned Nearby
Early detection and neighborly communication are key to avoiding larger problems. If you notice a potentially abandoned site:

1. Start with Outreach: If the landowner is known, a direct, respectful conversation can often resolve the issue. Many absentee owners are unaware of site conditions.
2. Involve the County: If no action is taken, contact the Napa County Agricultural Commissioner at:

• (707) 253-4357 or [email protected]. The office can assess the site and initiate abatement procedures if necessary.

Resources and Support

• Napa Valley Grapegrowers: Pest & Disease Resources
• University of California IPM: http://ipm.ucanr.edu
• Seasonal Best Practices: Video Library
• Napa County Agricultural Commissioner: countyofnapa.org/AgCom

By working together as a community of stewards, Napa Valley growers can uphold the integrity of our agricultural lands and protect the long-term sustainability of our vineyards—abandoned or not.
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For questions or support, please contact NVG at [email protected].