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Powdery mildew


New Member
Greetings. I'm hoping to get suggestions as to what to use to kill powdery mildew. It came on strong and spread fast. I burned all of my mature plants and kept two small plants in hopes of saving them. The mildew is coming back. I'm not sure I trust the dude at the grow store anymore because I think the mildew came from the dirt I bought there. So I'm asking for suggestions on what to use to kill it. Thank you in advance!


New Member
Bummer lucygrows. But thankfully not that bad of one. Had white powdery mildew on my first grow and learned that you can treat it with topical sprays to varying degrees of success. In my case it hadn't worked well. I then resorted to vaporizing sulfur to eradicate it, which worked. Haven't had a recurrence in over 5 years. Here's what I used: DIY Sulphur Burner/Evaporator

In my case I think it was environmental variables that I hadn't dialed correctly yet. Good control of high temperatures and humidity is very important. If possible, humidity under 50% is great.

You'll beat it. :thumb:


Well-Known Member
Mildew spores are everywhere, floating in the air, there’s no way to stop that. What you can do is keep them from proliferating by keeping humidity under control, and with good air circulation. I’m sure others will have other good suggestions.


Member of the Month: May 2022 - Photo of the Month: June 2022
Hey sorry about the powdery mildew ...... annoying stuff ... But if your looking for a natural solution, have you tried milk/water mix applied with a spray bottle? I've read a few places it works very well in treating mildew on plants. The science behind it is the proteins in the milk when exposed to sun(led) creates an antiseptic response that kills the mildew. This will help in treatment and prevention of what's on the plant but your air borne issue will still need to be addressed. As @Phytoplankton said controlled humidity and airflow will help wonders.

Good luck.
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