Has anyone defeated powdery mildew?

beacher

beacher

Active Member
Hey all, I've been having ongoing issues with powdery mildew for months now and can't figure out how to stop it.

My basement is old (more like a cellar) with water channels built into it to carry water to the sump hole. As a result there's often small pools of standing water around that I believe are a breeding ground for pm and other bad stuff.

Despite the roughness of the basement temps are humidity are pretty stable. Generally 45-55% humidity and around 72-76f temps. I also installed a cold air return down there so fresh air is constantly brought in and old air moved out.

Since the PM showed up one day I've tried many of the solutions recommended online. Sulfur spray, h2o2 and neem had seemingly no effect.

Potassium bicarbonate (mixed with veg oil and dish soap) worked OK, but the pm would come back in 5-9 days.

Lately I've been making lactobacillus serum and spraying weekly with that. I didn't see ANY pm for a few weeks so I assumed it was working and decided I would just spray it weekly as a preventative, but last night more pm showed up 6 days after spraying.

I'm at my wits end and considering just shutting down at this house. I could have lived with spraying every plant weekly, but every 5 days or less is just going to be too much.

Has anyone here actually defeated powdery mildew? Any suggestions or insight would be greatly appreciated!

Also if there are any good scientific resources on PM eradication that someone could point me to that would be great as well.

Thanks!
 
PadawanWarrior

PadawanWarrior

Well-Known Member
beacher said:
Hey all, I've been having ongoing issues with powdery mildew for months now and can't figure out how to stop it.

My basement is old (more like a cellar) with water channels built into it to carry water to the sump hole. As a result there's often small pools of standing water around that I believe are a breeding ground for pm and other bad stuff.

Despite the roughness of the basement temps are humidity are pretty stable. Generally 45-55% humidity and around 72-76f temps. I also installed a cold air return down there so fresh air is constantly brought in and old air moved out.

Since the PM showed up one day I've tried many of the solutions recommended online. Sulfur spray, h2o2 and neem had seemingly no effect.

Potassium bicarbonate (mixed with veg oil and dish soap) worked OK, but the pm would come back in 5-9 days.

Lately I've been making lactobacillus serum and spraying weekly with that. I didn't see ANY pm for a few weeks so I assumed it was working and decided I would just spray it weekly as a preventative, but last night more pm showed up 6 days after spraying.

I'm at my wits end and considering just shutting down at this house. I could have lived with spraying every plant weekly, but every 5 days or less is just going to be too much.

Has anyone here actually defeated powdery mildew? Any suggestions or insight would be greatly appreciated!

Also if there are any good scientific resources on PM eradication that someone could point me to that would be great as well.

Thanks!
Click to expand...
I actually dealt with it my second run since I didn't have the environment right, but my clone only Green Crack got over it, and I've had many successful rounds since. Here's the round 6 GC. Pics are from a few minutes ago.
IMG_4071.JPG
 
beacher

beacher

Active Member
@PadawanWarrior nice! How did you end up getting rid of it?

@FlakeyFoont really cool, I've never seen that in all my searching. Unfortunately a bit costly for me, but maybe I can build something similar myself. Thanks!

@Renfro I've been considering a sulfur burner next, I just worry it will leak into the house and smell everything up lol. Also do they leave a ton of sulfur dust on everything in the room?
 
Renfro

Renfro

Well-Known Member
beacher said:
@Renfro I've been considering a sulfur burner next, I just worry it will leak into the house and smell everything up lol. Also do they leave a ton of sulfur dust on everything in the room?
Click to expand...
Just cover up any CO2 sensors with a plastic bag. Turn off all fans. Vape the room in the dark, if plants are in there wait at least 30 minutes after lights out for the stomata to close.

If you have an empty room vape it nice and hard, like 12 hours. Now it's clean.

If you have plants in the room vape it for 4 hours, then skip a day, vape again, skip a week and vape again. After that you really shouldn't be seeing the PM anymore.

This is the only thing that I have found will eliminate the problem. Does it stink, yeah, does it go away, yeah. I don't notice the residue but you may.
 
beacher

beacher

Active Member
Cool, thanks. My plants are all in small grow boxes I built in the basement. If I were to do a sulfur burn would I keep the boxes ventilation going, or bring the plants out into the open for the burn?

I'd just want to make sure the insides of my rooms got blasted too.
 
FlakeyFoont

FlakeyFoont

Well-Known Member
beacher said:
@PadawanWarrior nice! How did you end up getting rid of it?

@FlakeyFoont really cool, I've never seen that in all my searching. Unfortunately a bit costly for me, but maybe I can build something similar myself. Thanks!

@Renfro I've been considering a sulfur burner next, I just worry it will leak into the house and smell everything up lol. Also do they leave a ton of sulfur dust on everything in the room?
Click to expand...
My grow is the crawlspace, with all our mechanicals, construction tools and such, so a sulfur burner was out.

After I'd lost a couple of ounces, it was a no brainer for me... even though it took me a year to get my brain working past the price, lol! Pays for itself pretty quickly, no spraying more moisture, no stink.

Not for everyone, just another option.

I'm pretty handy, and think I could cludge something together for about 100 beans with some stuff from HVAC units in air handlers.

Not pushin', just sayin'.
 
PadawanWarrior

PadawanWarrior

Well-Known Member
beacher said:
@PadawanWarrior nice! How did you end up getting rid of it?

@FlakeyFoont really cool, I've never seen that in all my searching. Unfortunately a bit costly for me, but maybe I can build something similar myself. Thanks!

@Renfro I've been considering a sulfur burner next, I just worry it will leak into the house and smell everything up lol. Also do they leave a ton of sulfur dust on everything in the room?
Click to expand...
The main thing that got rid of it was changing the environment.

But I sprayed them a few times with a vinegar/water mix, and was tried of spraying them so I said screw it. Well the Green Crack was the only one to have no more PM after 3 sprays, so I tossed the rest of the plants and kept this one. This plant has some good resistance to that shit.
 
MidcoastOrganic

MidcoastOrganic

Member
Burning sulfur can be dangerous, not recommended in a home environment.
Spraying a diluted milk solution is another choice. Many good recommendations here otherwise.
 
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beacher

beacher

Active Member
@FlakeyFoont oh cool I didn't realize you actually own one of those. How do you use it, by waving it over the plants or another way? Also do you treat your space with it somehow too?

Sound like your space is similar to mine...stifled air etc

"I'm pretty handy, and think I could cludge something together for about 100 beans with some stuff from HVAC units in air handlers."

Do you mean to build a similar light?
 
beacher

beacher

Active Member
@PadawanWarrior ya some strains and even phenos are definitely way more resistant to it than others. If this continues on I'll have to start picking genetics with that in mind. I've been making notes on the strains I have/start now to look for resistance as a trait.

@MidcoastOrganic yep, I've tried that one too. Most of these sprays (milk, h2o2, potassium bicarb, baking soda etc) I think would work fine for someone with an occasional minor problem, but mine is more ongoing...I need a nuclear option lol
 
C

ChristianGrowsitCrews

Member
beacher said:
Hey all, I've been having ongoing issues with powdery mildew for months now and can't figure out how to stop it.

My basement is old (more like a cellar) with water channels built into it to carry water to the sump hole. As a result there's often small pools of standing water around that I believe are a breeding ground for pm and other bad stuff.

Despite the roughness of the basement temps are humidity are pretty stable. Generally 45-55% humidity and around 72-76f temps. I also installed a cold air return down there so fresh air is constantly brought in and old air moved out.

Since the PM showed up one day I've tried many of the solutions recommended online. Sulfur spray, h2o2 and neem had seemingly no effect.

Potassium bicarbonate (mixed with veg oil and dish soap) worked OK, but the pm would come back in 5-9 days.

Lately I've been making lactobacillus serum and spraying weekly with that. I didn't see ANY pm for a few weeks so I assumed it was working and decided I would just spray it weekly as a preventative, but last night more pm showed up 6 days after spraying.

I'm at my wits end and considering just shutting down at this house. I could have lived with spraying every plant weekly, but every 5 days or less is just going to be too much.

Has anyone here actually defeated powdery mildew? Any suggestions or insight would be greatly appreciated!

Also if there are any good scientific resources on PM eradication that someone could point me to that would be great as well.

Thanks!
Click to expand...
Ivory soap mixed with Clorox bleach, carbon intake filter, 2 oscillating fans near ceiling another 2 on opposite side of room on the floor.
 
FlakeyFoont

FlakeyFoont

Well-Known Member
beacher said:
@FlakeyFoont oh cool I didn't realize you actually own one of those. How do you use it, by waving it over the plants or another way? Also do you treat your space with it somehow too?

Sound like your space is similar to mine...stifled air etc

"I'm pretty handy, and think I could cludge something together for about 100 beans with some stuff from HVAC units in air handlers."

Do you mean to build a similar light?
Click to expand...
We use the fancy term of sweeping, lol! And yeah, you can sweep the space, too. My space is a bit too big, and the light has to actually hit the mold, so nooks and crannies can be tough.

I've had to train my plants to be fairly open

Yes, something similar, but tbh, this thing is very nicely built, and it would be hard for me to home make something that's as elegant, for lack of a better word. The actual lamp and ballast can be bought from ebay HVAC suppliers, it's the case you'd have to make. I did find this pro unit on ebay for 325 willies, just a bit more than what I get for a zip, I'm small potatoes.

UV-c isn't something to play around with, ask the plants I started on, and it will fuck you up if you're not careful.

Not trying to sound like a pm evangelist, but not having to foliar is a big deal to me. Sulfur may work great, but just didn't seem to suit me, and all the other stuff was just bandaids, like you've seen.
 
beacher

beacher

Active Member
ChristianGrowsitCrews said:
Ivory soap mixed with Clorox bleach, carbon intake filter, 2 oscillating fans near ceiling another 2 on opposite side of room on the floor.
Click to expand...
Bleach sprayed on the plants? It doesn't kill them?

Most of my grow areas have 2 fans up top and one at floor level. Tons of airflow, I've often spotted pm first on leaves that are directly under the light and constantly dancing in the wind...it really doesn't make any sense lol
 
beacher

beacher

Active Member
@FlakeyFoont sweeping makes it sound pretty badass lol. And I'm way ahead of ya on training plants to be open, since this has stated I've become merciless about defoliation and training to allow for light/airflow

I've never worked with it but I'm definitely aware of the dangers of UV and would obviously take all precautions if I did try. So these lights are made to sanitize air going into HVAC systems? That's cool it's like those UV water systems..

Did you fry your plants when you started? Was fixing it a matter of less time, or less light?
 
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