The official WPM thread. Put it all here

Trying to scour this forum and every other forum for wpm information is time consuming and afaik won’t turn up all you need to know. So, let’s put it all here.


I’ll start off with what I’ve done for my grow and what’s happened.

I first found wpm after overcrowding plants in my Flower tent. 3 were too close, overlapping, with some leaves laying upon others. Do Not Overcrowd your Plants! Rh was 40-50%. Temps in the low to high 70’s
Upon discovery I pulled them apart, and gave them room. 1 plant had many leaves with wpm, the other just a couple, and the third seemed unaffected. No other plants in the tent showed any signs of infection.
I sprayed the 3 plants liberally with an h2o2 solution with water, (8oz h2o2/gal of water). It did nothing.
I then sprayed them with 50/50 milk solution.
This smelled horrible, and left white residue on all parts of the plant. I also bleached the interior of the tent.

After a week or two I got frustrated and not knowing if the white was milk proteins or spreading wpm. I sprayed with a 50/50 mix of h2o2 and water. It cleared off most of the milk and the plant looked good.
Several days later both plants started showing wpm. Especially the areas that didn’t get direct light or a full breeze.

Then I noticed wpm on other plants in the tent.

I sprayed them all liberally with straight 3% h2o2. The wpm disappeared. Many of the pistols on flowering plants turned brown. And the leaves didn’t seem too happy with that soaking. I once again bleached the tent.

Then more wpm again. Another round of straight h2o2. More unhappy leaves and an eventual return of wpm.

I ordered Safer garden fungicide. It’s sulphur based. Spraying it on the plants smelled a little, left some shy residue, but seemed to get rid of the wpm. At least for a few days. Then it was back. So I sprayed again. Same results.

This is my flowering tent. Some of the plants at this point were budding up. I opted to discontinue using the safer product because 1) it wasn’t working and 2) it would probably make the final buds taste horrible.

Next product was Serenade. It’s a Bayer product that uses a bacteria to fight wpm. Liberally dousing all the plants created a stench in my house akin to a pile of warm vomit in fresh manure. Yes, it does stink. This seemed to work for a few days, but eventually I saw signs of wpm again. I figured a natural bacteria would take a few rounds to properly eradicate the mildew. I sprayed with this for several weeks. Usually every 3-4 days. I’m assuming it’s ok to use during flower. Hopefully it won’t give the buds an off flavor.

At this point I started noticing wpm on my veg plants. 2 tents. 1 near the flowering tent and 1 2 floors up. Now I’m getting frustrated. I read up about Green cure. It’s a potassium bicarbonate based powder that works by raising surface pH on the plant so wpm cannot flourish. It’s not recommended for flowering plants, but by this point I’m ready to write off all my flowering plants and just try to save the genetics of my mothers and vegging plants.

I spray all the veg plants liberally. The next couple days show some sad leaves. Not nuked, but I can tell they don’t like it. Of course several days later wpm is back. I spray again with green cure. It works for a few days, irritates some leaves, but eventually the wpm is back.

I am now officially frustrated.

I’d like to finish up the plants in my flower tent. I feel the Serenade May keep the wpm at bay long enough, but I’m not 100% sure it won’t affect the buds flavor.
I’m convinced I can’t eradicate the wpm when there are infected plants in the house. After this round of flowering is done I’m going to have to clear the tent out, nuke it, and take it from there. I’m planning on building a permanent grow space where the tents currently are. I don’t want to go through all that to fight wpm again.

I have a couple questions though.
@garrigan62 @hightower9780 @dbrn32 @Myfriendis410 @MattyBear or anyone with first hand experience.

  1. Does anyone know if serenade is ok to use throughout flowering?

  2. I’d like to save the genetics from my mother plants. Would it make sense to cut clones, soaking them in a 50/50h2o2 bath, (except the very bottom of the stem where I’d apply clonex). I’m talking about literally submerging the entire cutting in the solution. Would this take care of the wpm? Would it kill the cutting? I’ve read it’s not systemic, so I’d assume eradicating spores from the entire surface could do it.

I know you’re having issues too with wpm. Maybe this will help.


What’s the RH in the tent? Gotta keep that down and the temps up. I remember your issues with peroxide too. But I think it’s the best bet out there. Best I can do is manage it and keep it in check as the plant is now fighting you as well: it’s basically dying as it flowers. I just plan to wash my harvest regardless of whether I see wpm or not.


Rh these days is 35%-45%.
Temps are high 60’s at night to low 80’s daytime.
I’m pretty sure wpm spores are wet and can easily spread and thrive in very low rh. Even surviving extended sub zero winters.


Mycorrhizae in a foliar spray will inoculate your plants from WPM. It can also be used as a treatment after an infection begins.

If used as an inoculate, do not apply other foliar sprays, as they’ll wash away the myco. If growing outside, reapply after rain.

And of course Hydrogen Peroxide is one of WPM’s greatest enemies. Used as a during grow treatment or an after harvest bud wash, H2O2 is absolutely necessary in any arsenal against WPM.


Has anyone used myco in this way for wpm? Is it effective?

I use h2o2 liberally. Always bathe my harvests. Spray before entering the flowering tent. I also spray with neem during veg.

Spraying even full strength h2o2 only knocks it down. I want to eradicate it.

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I found it’s all management once it’s been identified. Frankly, IMO unless you institute clean room procedures, wpm is gonna get in the grow space. Spores supposedly last forever but H2O2 is supposedly deadly to them. I have not used the Serenade but have used milk (protein skin is nasty) and Potassium Bicarb. Sodium Bicarb works too to raise the PH very high but you simply can’t get it everywhere.

In veg the only method is a sulfur burner but holy hell that would not be possible indoors.

All I can suggest is massive amounts of airflow, low RH (which does retard it’s spread) and as healthy a plant as possible up to harvest. Which reminds me to point out that this could be a very real issue: our current methodology is to deny the plant N during flower which of course causes multiple defs later in flower. This has to affect the plant’s ability to fight off disease. I’ve been supporting the plant all the way to harvest (with no ill effects on the smoke) and I’ve seen a reduction in wpm (didn’t really think about why).


You can see at the day of harvest just how green the plant material is.

My harvest (one plant) last month.


I hear you on the healthy as possible plants. At this point my plants are generally very happy, at least up until mid to late flower, where I put them through hell.

But the issue at hand isn’t that. Even my thriving veg and mother
plants are showing signs.

How about an ozonator? Can this be used in a tent with plants, or will it destroy them?

If I do nuke my entire grow, would running an ozonator throughout the house be a good approach to killing residual spores, or as you say, are they just everywhere and the best option isnt eradication but prevention?


I have used it this way and it was effective. I used AN’s Piranha and water in a spray. Treated outdoor pot plants located next to my yard, which had a major wpm infection.

Many commercial wpm sprays contain myco.


It’s worth a shot. I feel like I’ve tried everything else. :+1:

Any recommendations on the mycos? Or just the piranha?
I’ve been using the xtreme gardening mycos for transplant. Will that work?

I’ll gladly buy ANYTHING that actually works.


That only contains one strain of fungus? Hmmmmm, not sure on that.


I’ll just get the piranha. What’s another $35? Especially if it works.
Thanks for the tip, I’ll be sure to note it’s effectiveness.

Do you use the recommended foliar ratio for wpm?


I don’t really have much to add, sorry.

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You’re lucky then.

I’ve talked to several local cultivators. Guys that have been doing this for decades. One offered nothing but the same advice I found online. The other said this, “the only way to fix it is to chop it all down. Eventually you’re going to realize that you’re fooling yourself into thinking you can fix it. Just start over with clean genetics”. Food for thought.


I think I did 1 ml per liter.

Here’s some more GREAT info:


I would have told him he’s fooling himself if he thinks he’s eliminated it.

I do know that I’ve jarred up flower that had wpm resident and the stuff didn’t last 4 months before turning. I’m smoking stuff that I put down a year ago that a: had wpm and b: got a bud wash: the stuff is fantastic.


@Mrcrabs mentioned a foliar spray with insect frass could inoculate a good kind of mold that would compete with mold/bud rot. He actually mention bud rot specifically, but maybe it works for WPM.

As @Myfriendis410 says. Its never gone. Its present everywhere, we breath the spores daily. ts only a matter of the right conditions being present for it to present its self.

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I use insect frass as a foilar spray,as a preventative, just imagining your plant as a the hottest club in town and insects frass and his crew have filled up the whole club and there is no more room for the wpm to enter, security at the entrance is saying there’s no more room. Gots to go to a different club, fire Marshall’s orders, Hydrogen peroxide works as well but only if your not using living soil


There you go, and in terms all us guys can understand! Up in da club!