Pest, Weed, and Disease Management
How To Manage Pests, Weeds, and Diseases in Organic Farming
Summary: Organic farmers must first use preventative strategies to manage pests, weeds, and diseases. These include crop rotation, sanitation, and healthy soil practices. If prevention isn’t enough, biological, botanical, or approved inputs may be used with documentation. Emergency treatments mandated by federal or state programs are allowed under specific conditions, as long as affected crops are not sold as organic.
Preventative Management Practices (First Line of Defense)
Organic certification requires using preventative strategies first before any other pest, weed, or disease controls. These practices build long-term soil and crop health, which naturally reduces pest and disease pressure.
Best practices include:
- Crop rotation: Disrupts pest and disease life cycles.
- Soil nutrient management: Supports strong plant immunity.
- Selecting regionally adapted seed and crops: Increases resistance to local pests and diseases.
- Sanitation: Cleaning tools, removing diseased plant material, and minimizing pest habitat reduce vectors.
Allowed Pest Control Practices
If preventative practices are not enough, you may use non-synthetic pest control strategies, such as:
- Beneficial insects: Introduce natural predators or build insect habitat.
- Pheromones and lures: Disrupt pest mating cycles.
- Traps and repellents: Help reduce pest populations without chemical intervention.
Allowed Disease Control Practices
Organic farms manage disease through year-round cultural and biological methods, including:
- Mulching with green manure or compost: Builds soil health and suppresses disease organisms.
- Drip irrigation: Reduces moisture on plant surfaces, helping prevent fungal spread.
- Approved biological or mineral inputs: May be used if prevention is not enough (must be allowed under organic rules).
Allowed Weed Control Practices
Organic weed management includes mechanical and cultural tools, such as:
- Mulching
- Mowing
- Livestock grazing
- Flame weeding
- Hand weeding or mechanical cultivation
These strategies are often used together to maintain effective weed control throughout the season.
What If Prevention Fails?
When pests, diseases, or weeds cannot be controlled through prevention or allowed cultural methods:
- You may use an allowed input listed on the NOP National List of Approved Substances.
- Materials that are OMRI-listed or WSDA-approved are generally acceptable.
- If the material is not listed by OMRI or WSDA, you must get prior approval from Oregon Tilth before use.
Important:
You must always document:
- Why the input was needed.
- What conditions made its use necessary.
- How it was applied and at what rate.
- That preventative strategies were attempted first.
Emergency Treatments from Government Programs
Sometimes, government authorities require the use of prohibited substances to control emergency pest or disease outbreaks.
Will I lose organic certification?
No, but only if:
- The affected crop or plant parts are not sold or labeled as organic, and
- You document everything related to the emergency treatment.
Required documentation:
- A copy of the state or federal emergency order.
- Details on the material and why it must be used.
- Proof that no organic alternative exists.
- Locations, application schedule, and crop-specific data (e.g., growth stage).
We recommend notifying Oregon Tilth as early as possible if you are impacted by a government treatment order.
Learn More
🎥 Watch: Preventative Pest, Weed, and Disease Practices for Organic Farms (Washington State Department of Agriculture + USDA NOP)
📧 Have questions? Contact us.