Spraying diluted milk on the leaves prevents or cures powdery mildew.
Contested
Milk spray for powdery mildew is the rare home remedy with real trials behind it — diluted milk cut mildew on squash and cucumbers in field studies, sometimes as well as a fungicide. But it isn't a guaranteed cure: results swing with crop and weather, and it's a preventive, not a rescue. Use it if you like, but lean first on resistant varieties, good spacing and airflow, and pulling infected leaves.
What is actually known
Unusually for a home remedy, this one has real trials behind it: diluted milk sprayed on cucurbits reduced powdery mildew severity in controlled field studies, in some cases comparably to a conventional fungicide. But it is not the settled cure the enthusiasm suggests. Results vary a lot by crop, dilution and climate; the mechanism is not pinned down (proposed routes include milk salts and proteins generating reactive oxygen in sunlight); and too strong or too frequent a spray can leave its own residue and odour. It works best as a preventive on a susceptible crop, applied alongside — not instead of — the things that reliably matter: resistant varieties, spacing and airflow, and removing infected leaves.
Evidence: not yet confirmed against its 3 sources.
what this rests on - 3 pointers
controlled field trials on cucurbits report diluted milk sprays reduced powdery mildew severity
sometimes comparably to fungicide; results inconsistent across crops and the mechanism is unresolved; general knowledge
not verified here
When would that grow at your place? →
Cite this page
Milpa Gardens. "Spraying diluted milk on the leaves prevents or cures powdery mildew." Evidence grade: Contested. https://milpa.garden/beliefs/milk-spray-powdery-mildew/
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