Does hydrogen peroxide help treat root rot?
Written by
Nguyen Minh
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Hydrogen peroxide treats root rot by disinfecting diseased roots and eradicating surface fungus. This method has been effective for me for many years. It allows oxygen to get to the roots while killing deleterious pathogens. Dilution and time of application are critical to success.
Solution Preparation
- Mix one part 3% hydrogen peroxide with four parts water. Never use stronger concentrations. I store mixed solution in dark bottles. This prevents light degradation that reduces effectiveness.
Root Treatment Process
- Submerge cleaned roots for 5-10 minutes depending on infection severity. Watch for bubbling indicating oxidation. Rinse thoroughly after treatment. I set timers to avoid overexposure which can damage healthy tissue.
Soil Drench Technique
- Apply diluted solution directly to soil for mild cases. Use 1 cup per 6-inch pot. Repeat weekly for persistent fungus gnats. This method kills larvae while aerating compacted soil around roots.
Hydrogen peroxide is most effective when used in conjunction with root pruning and/or soil replacement. Hydrogen peroxide is effective against pathogens at the soil surface, but it does not penetrate deep into infections and subsequent rotting. I only use it for very early-stage rot. For advanced root rot, commercial fungicides and treatments penetrate more effectively into root tissues.
Never rely solely on hydrogen peroxide for treatment. Use it in conjunction with complete soil replacement and altered watering. After treating the roots and repotting in a fresh soil mix, I see the best results. Watch the plants for two weeks after applying to see if new roots have formed.
Safety is a priority when managing hydrogen peroxide. Use gloves and avoid letting it come into contact with your eyes. Keep hydrogen peroxide away from heat and light, and store it in a cool, dry place, away from other garden chemicals. Appropriate storage will help your product remain effective for the next time you use it.
Hydrogen peroxide is a cheap first defense against root loss. It's more affordable than commercial fungicides and works more quickly. For organic gardeners, I highly recommend it. However, keep in mind that it works in conjunction with proper cultural practices, such as effective drainage and moisture management, not instead of them.
Read the full article: How to Treat Root Rot: A Complete Guide
