How to fight spider mites using alcohol? - briefly
Mix equal parts of 70% isopropyl alcohol and water, then spray thoroughly onto affected leaves, ensuring coverage of the undersides where spider mites hide. Reapply every 5–7 days, avoiding direct sunlight during application to prevent leaf damage.
How to fight spider mites using alcohol? - in detail
Alcohol is an effective contact agent against spider mites when applied correctly. The solution must contain a concentration that penetrates the mite’s exoskeleton without harming the plant. A mixture of 70 % isopropyl alcohol and water at a ratio of 1 part alcohol to 9 parts water (10 % solution) provides optimal efficacy for most ornamental and vegetable species. For delicate foliage, reduce the concentration to 5 % (1 part alcohol to 19 parts water).
Application steps:
- Mix the solution in a clean spray bottle; add a few drops of mild liquid soap as a surfactant to improve leaf coverage.
- Test the spray on a small leaf area and wait 24 hours; observe for any phytotoxic symptoms such as discoloration or wilting.
- If no damage occurs, spray the entire plant until runoff, targeting the undersides of leaves where mites congregate.
- Repeat the treatment every 3–5 days until mite populations decline, typically after three to five applications.
- After the final spray, rinse foliage with plain water to remove residual alcohol and prevent buildup.
Key considerations:
- Apply in the early morning or late afternoon to avoid rapid evaporation and leaf burn.
- Do not use undiluted alcohol; concentrations above 20 % can cause tissue damage.
- Combine alcohol treatment with cultural controls—regular pruning, removal of infested leaves, and maintaining low humidity—to reduce mite reproduction.
- Monitor plants regularly with a hand lens; count mites on several leaves to assess treatment progress.
- For greenhouse or indoor settings, ensure adequate ventilation during and after application to minimize inhalation risks.
Safety precautions:
- Wear gloves and eye protection when handling alcohol solutions.
- Store unused mixture in a labeled, sealed container away from heat sources.
- Keep away from children and pets; alcohol is flammable, so avoid spraying near open flames.
By adhering to these guidelines, growers can suppress spider mite infestations efficiently while preserving plant health.