Watering with hydrogen peroxide oxygenates the roots and cures root rot.
Hydrogen peroxide won't oxygenate your roots in any lasting way. It breaks down in soil within hours, and it can harm the helpful life in the soil. It can kill some fungi, but root rot comes from waterlogged soil, and peroxide doesn't change that. Fix the drainage and ease off the watering.
What is actually known
Hydrogen peroxide does break down into water and oxygen, which is where the idea comes from, but it is no lasting supply to the roots. In soils it breaks down within hours (measured half-lives run from about one to seven hours), fastest where there is more organic matter. It is not harmless to the soil either. It can damage or destroy soil organisms, and large treatments can harm mycorrhizal fungi. Peroxide is a real broad-spectrum fungicide, used as a soil drench, but it does not fix what causes root rot. The water molds behind it live in practically all cultivated soils and kill roots when poor drainage or overwatering keeps the soil wet. Good drainage and water management are what control it.
The evidence
Evidence: checked against 3 sources in the research-based literature.
The 3 sources
Non-target soil organisms may be damaged or destroyed following application of hydrogen peroxide
In surface soils with higher organic matter or manganese content, H2O2 usually decayed rapidly, with disproportionation to water and dioxygen dominating the decomposition
Under wet conditions brought about by poor soil drainage or excess irrigation, more and more roots are killed and the plant may wilt, stop growing, or even collapse and die
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Cite this page
Milpa Gardens. "Watering with hydrogen peroxide oxygenates the roots and cures root rot." Evidence grade: Contested. https://milpa.garden/beliefs/hydrogen-peroxide-plants-peroxide-root-rot/
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