22 days to harvest with PM! HELP!

Please help me!! I am a novice grower with a indoor grow room in my house. I have 2 plants that are flowering and 22 days away from harvesting with powdery mildew. I have clipped all the infected leaves away and sprayed with neem oil with a little success. But not enough!!! What can i use on the ENTIRE PLANT BUD AND ALL? And do i need to rinse it off after the application? Milk and water sounds the most promising but do you need to rinse it off? What about the Acv treatment, do you rinse it off? I read ALOT, but everythingmis so vague, PLEASE HELP ME!!!

Welcome I have heard of milk and water supposedly the protein in the milk is supposed to help but you can also mist the affected areas with hydrogen peroxide h2o2. To prevent Powder mildew you got to get that air circulating. If not already add a couple fans.

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Here’s a question for the community; at what point do you tear down, scrub clean, and begin again?

@Sarasapp can you post a picture or two? Ideally, it’d be great to see before and after you defoliated.

Can you tell us about your grow environment? Where is it? What are your temps (light and dark)? Same for humidity.

What cultivar(s) are you working with?

I’m so sorry you ran into this. Don’t be discouraged, however this turns out. Welcome to the forum.


Hi @Keystonecops thanks so much! I don’t know if my pictures uploaded or not. I am just using regular moisture control soil. My grow room is just an extra bedroom we hung lights in and converted to a grow room basically. I’m so new at this, I stink!! Lol. PH levels? What? Duh…that would be. I fell into this. I am a medical marijuana patient who really can’t afford this and when I got a chance at some plants that ALREADY had problems…well, I couldn’t pass it up. So I got these 3 plants at different stages, two are now flowering. I nursed them back, YAY!! But now the PM. I have fans, I have no humidity to speak of. It stays at around 30% constantly, my temps stay at around 77 to 80 during the day and 68 to 73 in darkness.


Thanks so much, I defiantly have fans, I don’t understand this!! Ugh…

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Me knowing me I’d pull it and start again. Or if I could put it outside I would. I have way to many seeds so if I pulled it, I’d use it to make vape juice or Cannabutter. You get the idea. Smoking it? Nope.

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Your plants may have come in with PM. It colonized long before you could actually see it.

I’m gonna qualify all my advice with “I have not tried to recover flowers that had PM. I’m not a doctor, nor am I a botanist. I do not know what smoking, vaping, or eating flowers with PM or curative applications will do to you.”

I believe peroxide diluted with water will kill PM. Water and Dawn will wash it away. The problem is that PM seems to dwell in the plant’s outer tissue. Once it gets a foothold, it’s very hard to eliminate.

I would bring my temperature down to 75 max. Your humidity is already low. I wonder if you don’t have a microclimate due to poor air circulation.

Take the plants out of the room and sterilize everything. Wash all linens, wipe walls with 1:10 bleach, and do anything else you can to clean the spores out of there.


Hard to say @KeystoneCops. I’m sure I’d just toss it as I have worked with mold and bacteria. I’m pretty picky. I studied one bacteria that took 500 degrees Celsius to kill it.

The Professor thought I created a new virus and said Autoclave it right away. I did. But I decided to redo what the one person wrote for their PhD degree. What actually happened was no one saw how the bacteria adapted to the solution it was in.

Once it was starting to adapt, it actually looked like Sickle Cell. It was so cool to watch it and I got the Professor and he was impressed. I was using a $250k microscope. He didn’t get a camera adaptor so pictures could be taken. Still cool.

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@kellydan Thanks so much for the advice, as you can see I have defoliated my plant quite a bit, my husband laughingly refers to it as a TIA stick!! Can you tell me the ratio please of peroxide to water in a gallon? And do you wash it off? I’m full of questions! Do you put it on right before darkness? Does it go on during light hours?

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@KeystoneCops Thank you so much I will most certainly do that immediately!! I’m hoping it helps.

@Sarasapp I would go with a 50/50 mix with water in a spray bottle mist affected areas . I would go with the daylight. As far as wash I would like to tag a friend that has become a go-to on this topic. @Myfriendis410


I see a lot of things. First off; the plants pictured are FAR from being ready to harvest. They look to be 3 weeks into flower.

Second; a better picture, in focus, in natural light is really necessary to show the community what is really going on.

Third; environmental factors other than stated should be noted. In particular:

This is bad juju. Low PH is inevitable and high salts which besides causing a harsh smoke, burning the leaves etc. it stresses the plant when it’s immune system is compromised (in flower).


If you spray mature flower with neem oil it will ruin it.

3% peroxide and distilled water, 50/50, spray with an atomizer the entire plant including the undersides of the leaves. Soak the flower. Immediately get a fan on it with LOTS of airflow.

If severe and before trichomes form, you can use a dilute solution of isopropyl alcohol but remember alcohol dissolves THC so only until flower.

All of that said; until I see actual pictures of WPM on your plants I would advise to do nothing.


@Myfriendis410 Thank you so much for your advice. Here is some more pictures for you. The first one is the top of my freefall clone, no Wpm there. The next two are the bottom of the freefall. Then the next picture is the Banana Kush. You can plainly see the Wpm there. I just want to save my plants. Thanks so much. I am planning on breaking everything down like @KeystoneCops said and cleaning my grow room immediately.


Definitely early in flower. Try the peroxide treatment before anything else. There is another product, Azos? Something like that and is very expensive but supposedly works.

You probably have 6 weeks or more to go FYI.


I thoroughly clean my grow rooms between every grow. That includes wall, ceilings, floors and all equipment in and around the grow areas.

I do this regardless of whether or not I have had any issues.


That’s good practice. I meant at what point would you abandon a grow and start fresh?

1tbs baking soda, 1tbs veg oil, and 1-3 drops of liquid soap per gallon of water. Treat with lights off and dry good after treatment. I also do a post harvest wash to be on the safe side. Treat weekly.

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