What's Allowed for Pest, Weed, and Disease Control on an Organic Farm?

1Tier 1 — Prevention and cultural practices (always first)

Section §205.206(a) requires the producer to use "management practices to prevent crop pests, weeds, and diseases," specifically:

• (1) crop rotation and soil and crop nutrient management practices under §205.203 and §205.205;
• (2) sanitation measures to remove disease vectors, weed seeds, and habitat for pest organisms; and
• (3) cultural practices that enhance crop health, including the selection of plant species and varieties with regard to suitability to site-specific conditions and resistance to prevalent pests, weeds, and diseases.

This is the foundation. A resistant variety, a clean rotation, and good sanitation are not "nice to have" — they are the required first line, and an inspector will expect to see them in your plan before any intervention.

2Tier 2 — Mechanical, physical, and biological controls

When prevention isn't enough, §205.206(b)–(d) provide the next tier:

• Pest problems (§205.206(b)) may be controlled through augmentation or introduction of predators or parasites of the pest species; development of habitat for natural enemies of pests; and nonsynthetic controls such as lures, traps, and repellents.
• Weeds (§205.206(c)) may be controlled through mulching with fully biodegradable materials; mowing; livestock grazing; hand weeding and mechanical cultivation; flame, heat, or electrical means; or plastic or other synthetic mulches, provided that they are removed from the field at the end of the growing or harvest season.
• Disease (§205.206(d)) may be controlled through management practices that suppress the spread of disease organisms, or application of nonsynthetic biological, botanical, or mineral inputs.

3Tier 3 — An approved substance, but only conditionally

This is the paragraph that governs spraying. Under §205.206(e):

Two conditions, both required. First, the earlier tiers must have proven insufficient — you can't skip to a spray because it's easier. Second, the conditions for use must be documented in your OSP before you use it. The substance itself must be on the National List at §205.6012; how to verify a specific brand-name product is covered in Is this input allowed?.

4One flat prohibition

Section §205.206(f) bans one thing outright: a producer may not use lumber treated with arsenate or other prohibited materials for new installations or replacement purposes in contact with soil or livestock. Old treated posts already in the ground don't have to be ripped out, but you can't add new ones.

5Why the order matters at inspection

Inspectors don't just check what you applied — they check why, and whether the decision followed §205.206's hierarchy. The question they're really asking is: "Show me that prevention and physical controls came first, that they were insufficient, and that this substance's use was written into your plan before you reached for it." If you sprayed an approved product but there's no record of the tiers that preceded it, that's a noncompliance even when the product itself was allowed.

6How to document this on your farm

The defensible record is a short narrative per intervention: what pest/weed/disease pressure you saw, what preventive and physical measures were already in place, why they fell short, and what you applied in response. That's a lot to reconstruct months later from memory.

OrganicAssistant captures it as you go — note the problem and the action in your farm chat ("flea beetle pressure on the brassicas, row cover wasn't enough, applied [approved product] today") and it logs the input, the field, the date, and the reason, building the §205.206 paper trail automatically. You can then draft your OSP's pest-management section straight from those records.

7The bottom line

Organic pest control is a sequence, not a shopping list. Prevention and cultural practices first, then mechanical and biological controls, and an approved substance only when those are documented to be insufficient. Get the order — and the paperwork — right, and the spray decision defends itself.

This explainer summarizes federal regulation in plain language; it is not legal advice or a compliance determination. Your certifier makes the final call on your operation. Reviewed against the eCFR text of 7 CFR § 205.206 current as of 2026-07-22.