Pyrethrin
Quick Facts
- Type
- Botanical
- Source
- Extracted from the flowers of Chrysanthemum cinerariifolium (pyrethrum daisy)
- OMRI Listed
- Yes ✓
- Bee Safe
- No — apply in evening
- Pet Safe
- Caution
- Residual
- Very short — degrades in sunlight within 12-24 hours
- Best For
- Quick knockdown of visible pest infestations. Emergency "rescue treatment" when populations spike.
What Is Pyrethrin?
Attacks the sodium channels of insect nervous systems, causing rapid knockdown (paralysis within minutes). However, many insects recover from sublethal doses without a synergist like PBO. Breaks down in UV light within hours.
Source: Extracted from the flowers of Chrysanthemum cinerariifolium (pyrethrum daisy)
What Pests Does Pyrethrin Kill?
Pyrethrin is effective against the following pests:
How to Apply Pyrethrin
Best for: Quick knockdown of visible pest infestations. Emergency "rescue treatment" when populations spike.
Avoid for: Near water features, during bee hours, around cats. Not for long-term control alone.
Residual activity: Very short — degrades in sunlight within 12-24 hours
Safety Profile
| Category | Rating |
|---|---|
| Bee Safety | 🔴 Toxic to bees while wet |
| Pet Safety | 🔴 Use caution around pets |
| Overall Rating | Caution — Use with caution — timing and technique matter |
Why Isn't Pyrethrin Working?
If Pyrethrin isn't delivering results, check these common failure modes:
Insect recovery — without a synergist (PBO), many insects recover from knockdown
UV degradation — loses potency within hours of sunlight exposure
Toxic to fish and aquatic invertebrates — never spray near water
Toxic to cats — synthetic pyrethroids especially dangerous to felines
Confused with pyrethroids — synthetic versions are NOT organic
Best Pyrethrin Products
PyGanic
SprayOMRI-listed, no PBO synergist — pure pyrethrin
Bonide Pyrethrin Spray
RTU SprayGarden-use pyrethrin concentrate
Evergreen Pyrethrum
ConcentrateProfessional strength, OMRI-listed