Why Dish Detergent Burns Tomato Plants: Soap vs. Detergent

A 1:5 detergent-to-water spray destroyed tomato plants because household detergents are harsh surfactants, not insecticidal soaps. Proper insecticidal soap concentration is 1:50 (2%).

Critical Distinction

• Insecticidal soaps: Potassium salts of fatty acids — designed for plant safety.
• Dish detergents: Synthetic degreasers — strip leaf cuticles, cause necrosis.

Safe Practice

Use only products labeled for insect control on plants. Homemade soap sprays are unreliable and risky. Commercial insecticidal soaps are affordable and formulated for efficacy and plant safety.