My first dealing with the infamous white powdery mildew

Couch_Lock

Well-Known Member
I've tried this spray application before and had 0 results. I had negative pressure when I started in the room after I lined it with panda film, it was pulling the panda film inwards so I knew that I was at negative pressure but lo and behold PM began to develop. Heck I even took precautionary measures by spraying them with neem oil twice a week. So at that point I cut in a return grill assembly with a allergen filter and began using it as a fresh air intake. This pm seems to be producing at lights off.
I noticed a reduction in growth when I began turning off the humidifier during lights off. Last night I tried turning up the electric heater thinking that would help but it seemed worse. So I'm truly at a loss. These 5 plants that have PM are auto's that are 5wks in flower. One additional thing I tried last night 4 hrs before lights out was I sprayed only the affected leaves with neem oil and it didn't work. The balance of plants in the room shows no signs of PM.
The pm is showing up on random fan leaves and on sugar leaves near the buds but hasn't gotten on the buds "yet". I'm concerned about spraying anything near the bud sites because of my experience I had on my previous grow. I've spent lots of money and time I hate to forfeit it :cuss:
Most of the sure fire remedies would affect taste for sure......keep googling a cure, bud.

I wish you luck, I know the work + effort involved in a good grow. I cut all power to my grow tent at "lights out"...fans, humidifiers........never had an issue so far

I have no exp whatsoever on auto plants, but they should be more resilient to pests., molds and mildew

Using water that is not distilled in a humidifier can cause PM.........thats why I have 50 gallons of DW in my cellar.

I run 19/5 in veg....standard 12/12 flower
 

Bourbon 2

Well-Known Member
Killing PM
View attachment 4466529

Based on my experience with Regalia I'd run Marrone Grandevo for Mites

Good luck
I bought a quart of it yesterday and I mixed per instructions for foliar application. I saturated it under the leaves and on the canopy. Today I just peeked at it and still seen signs of PM. For $80 a quart I expected good results but had better results with 2% milk. I'll read more on the product and see how often I can spray, maybe its gonna take multiple applications, idk... It isn't like it's from top to bottom, it's only here n there..
Cheers :weed:
 

curious2garden

Well-Known Mod
Staff member
I bought a quart of it yesterday and I mixed per instructions for foliar application. I saturated it under the leaves and on the canopy. Today I just peeked at it and still seen signs of PM. For $80 a quart I expected good results but had better results with 2% milk. I'll read more on the product and see how often I can spray, maybe its gonna take multiple applications, idk... It isn't like it's from top to bottom, it's only here n there..
Cheers :weed:
You have to saturate everything. I had to do multiple applications and it eradicated it. @Samwell Seed Well @Tangerine_ any other hints on using it?
 

Samwell Seed Well

Well-Known Member
You have to saturate everything. I had to do multiple applications and it eradicated it. @Samwell Seed Well @Tangerine_ any other hints on using it?
I suggest using an initial high rate for active outbreaks, with 2nd and 3rd application and normal rate, 3-4 days apart.

You can use a spreader(surfactant, i.e cocowet, capsil )and if you apply it an hour before your lights come on or allow them to have 30 min of darkness with little no no air movement after applying it will have a better efficacy.
 

Bourbon 2

Well-Known Member
I suggest using an initial high rate for active outbreaks, with 2nd and 3rd application and normal rate, 3-4 days apart.

You can use a spreader(surfactant, i.e cocowet, capsil )and if you apply it an hour before your lights come on or allow them to have 30 min of darkness with little no no air movement after applying it will have a better efficacy.
I bought a sulphur burner, I know that I have to use it lights off and no fans. I've been putting it off because of not being sure about the residual effects on everything..
 

Tangerine_

Well-Known Member
For off, please forgive me if this is all over the place. I've been staggering around with PBBV all week and its kicking my ass.

I use Regalia for two reason.
One, its extremely safe. There are few effective products available that can pass lab testing. Even a simple EWC tea will often fail and while I don't bother with testing, I do share with others.

And two, its a VERY effective preventative, especially in areas where PM thrives or if you take in clones. Some of the older cuts are very susceptible to pathogens. I spotted some PM last summer one of the Chem 4 clones and I tossed it and immediately treated the area.
The other Chem4 cutting was heavily treated with Regalia and it there were no signs of PM thru harvest.

I don't know of any one and done bullet proof cure for plants in infected with PM in flower.
PM acts systemic and every time an infected area is touched, even a little, thousands of spores are released. When they land, they'll either find the tissue inhospitable (high brix leaves and/or treated with Regalia) or they find it ideal and "bite in."

When treating plants, up the dosage and be very thorough. Leave the fans off while the Regalia penetrates but then you'll want to get the air moving and keep it moving. You should alternate with another product too. I use Cease.

Any new seeds should be germ'd and vegged away from your infected room. In fact, I'd toss anything in veg that could've been infected with spores.
You can limp through flower with PM, but to fully eradicate from future grows takes some diligence. Sulfur burners are effective too. The sulfur vapors can get to the areas you might miss with foliar sprays.
Good luck. I hate to see people battling this shit.
 
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Bourbon 2

Well-Known Member
Sulfur burners work great. Just be ready for weak leaves to drop off and make sure the area directly beneath your burner is completely clear
Well I was wrong. What I saw under my HPS light was the minerals left behind from the foliage application and not PM. I looked closely at my plants under the LEDs and much the same, no PM. I need to water tomorrow so I'll add the Regalia as a soil drench. Cheers :weed:
 

Bourbon 2

Well-Known Member
For off, please forgive me if this is all over the place. I've been staggering around with PBBV all week and its kicking my ass.

I use Regalia for two reason.
One, its extremely safe. There are few effective products available that can pass lab testing. Even a simple EWC tea will often fail and while I don't bother with testing, I do share with others.

And two, its a VERY effective preventative, especially in areas where PM thrives or if you take in clones. Some of the older cuts are very susceptible to pathogens. I spotted some PM last summer one of the Chem 4 clones and I tossed it and immediately treated the area.
The other Chem4 cutting was heavily treated with Regalia and it there were no signs of PM thru harvest.

I don't know of any one and done bullet proof cure for plants in infected with PM in flower.
PM acts systemic and every time an infected area is touched, even a little, thousands of spores are released. When they land, they'll either find the tissue inhospitable (high brix leaves and/or treated with Regalia) or they find it ideal and "bite in."

When treating plants, up the dosage and be very thorough. Leave the fans off while the Regalia penetrates but then you'll want to get the air moving and keep it moving. You should alternate with another product too. I use Cease.

Any new seeds should be germ'd and vegged away from your infected room. In fact, I'd toss anything in veg that could've been infected with spores.
You can limp through flower with PM, but to fully eradicate from future grows takes some diligence. Sulfur burners are effective too. The sulfur vapors can get to the areas you might miss with foliar sprays.
Good luck. I hate to see people battling this shit.
So ive been altering foliar sprays using Regalia and Heavy 16 Foliar. I noticed PM on a some fan leaves. I removed them and saturated the plants top to bottom again with Regalia. The room is lined top to bottom with panda film and 3 fans, 1 hepa fan, 1 dehumidifier and 1 carbon filter. I foliar spray twice a week I even add Regalia as a soil drench. So frustrated....:wall:
 

Tangerine_

Well-Known Member
So ive been altering foliar sprays using Regalia and Heavy 16 Foliar. I noticed PM on a some fan leaves. I removed them and saturated the plants top to bottom again with Regalia. The room is lined top to bottom with panda film and 3 fans, 1 hepa fan, 1 dehumidifier and 1 carbon filter. I foliar spray twice a week I even add Regalia as a soil drench. So frustrated....:wall:
I feel your pain. Honestly though, once it gets into your bloom room, all you can do is limp those plants to harvest and keep all other plants in a separate area until you can clean your room. Sulfer burners will help a lot.
If you have plants in veg that you think could be infected, just toss them and start fresh.
I'm hesitant to suggest EW20 after reading so many posts from people who spray that shit right before flower. It can be used safely to save genetics but you'll need to clone out at least 3 generations. Few plants are worth this IMO.
RAs and PM is my biggest fear. I run perpetual and it would surely shut me down for several months.
Sending ya postive vibes and the will to win this battle.
 

Tangerine_

Well-Known Member
Oh and maybe try alternating with potassium bicarbonate (Green Cure) or one of the soybean oil citric acid concoctions on the market like Green Cleaner. GC, kinda works for PM. IMO, its best used as a contact killer for spider mites. And it will linger on the flowers and leave behind an unbearable taste.
Neither will penetrate deep enough to eradicate PM from the tissue but Green Cure will kill and dry up active spores on the surface. It also changes the pH of the leaves making it a little inhospitable for PM.
And watch your pistil, both will burn the shit out of them.
 
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etruthfx

Well-Known Member
So ive been altering foliar sprays using Regalia and Heavy 16 Foliar. I noticed PM on a some fan leaves. I removed them and saturated the plants top to bottom again with Regalia. The room is lined top to bottom with panda film and 3 fans, 1 hepa fan, 1 dehumidifier and 1 carbon filter. I foliar spray twice a week I even add Regalia as a soil drench. So frustrated....:wall:
Dehumidify to 30% at least is going to be the first step. Then use a treatment like Lost Coast plant therapy or anything like that actually works and that will take care of the problem. Don't use Eagle 20 in flower under any circumstances, if you must use it to treat your plants in veg thats a more tactical approach. Don't go spraying shit like that anywhere near flowering plants. Airflow is good when preventing PM, but not when there are spores present so keep the fans low until after foliar treatment has worked and spores are gone. No way to get PM out of the buds from what I know, only the leaves.
 

Bourbon 2

Well-Known Member
I feel your pain. Honestly though, once it gets into your bloom room, all you can do is limp those plants to harvest and keep all other plants in a separate area until you can clean your room. Sulfer burners will help a lot.
If you have plants in veg that you think could be infected, just toss them and start fresh.
I'm hesitant to suggest EW20 after reading so many posts from people who spray that shit right before flower. It can be used safely to save genetics but you'll need to clone out at least 3 generations. Few plants are worth this IMO.
RAs and PM is my biggest fear. I run perpetual and it would surely shut me down for several months.
Sending ya postive vibes and the will to win this battle.
Thanks for the positive vibes, I need it.
I had to toss out my previous grow because of PM. I fought it during veg into flower. Everything I used including Green Cure kept it at bay but 6wks into flower the green Cure nuked the pistols. The catalyst were still swollen but it no longer produced trichs so I tossed everything..
I thought I was proactive by heating up the room to 110 degrees for over an hour, I bleached everything, walls, ceiling and floors. I then lined the entire room with panda film and taped the seams. I bought Regalia and treated during veg as a soil drench and foliar application along with the Heavy 16 foliar spray. This is in my basement and in the adjacent room I noticed white mildew on my black guitar case. So ive got to get through this grow and then eradicate it this summer. I'm feeling defeated, errrrrr... :wall:
 

etruthfx

Well-Known Member
Thanks for the positive vibes, I need it.
I had to toss out my previous grow because of PM. I fought it during veg into flower. Everything I used including Green Cure kept it at bay but 6wks into flower the green Cure nuked the pistols. The catalyst were still swollen but it no longer produced trichs so I tossed everything..
I thought I was proactive by heating up the room to 110 degrees for over an hour, I bleached everything, walls, ceiling and floors. I then lined the entire room with panda film and taped the seams. I bought Regalia and treated during veg as a soil drench and foliar application along with the Heavy 16 foliar spray. This is in my basement and in the adjacent room I noticed white mildew on my black guitar case. So ive got to get through this grow and then eradicate it this summer. I'm feeling defeated, errrrrr... :wall:
Powdery mildew won't grow on items thats a different type of white mold
 

Bourbon 2

Well-Known Member
Powdery mildew won't grow on items thats a different type of white mold
4wks ago I scrambled to get clippings for my cloner and placed it temporarily in my mancave outside of my grow room and 2wks in I noticed PM on some of the leaves. I tossed out everything, bleached the cloner and pucks. Assembled one of my tents, sanitized it, added a quality allergen filter to the air intake screen and took new clippings. Everything now seems to be healthy within the tent. But its very apparent that I have the spores lingering in the basement...I'll have to really decide if this is worth the aggravation :spew:
 

Tangerine_

Well-Known Member
4wks ago I scrambled to get clippings for my cloner and placed it temporarily in my mancave outside of my grow room and 2wks in I noticed PM on some of the leaves. I tossed out everything, bleached the cloner and pucks. Assembled one of my tents, sanitized it, added a quality allergen filter to the air intake screen and took new clippings. Everything now seems to be healthy within the tent. But its very apparent that I have the spores lingering in the basement...I'll have to really decide if this is worth the aggravation :spew:
The white mold on your guitar case isn't the same kind that affects cannabis but does indicate moisture. I think you're going to have to start completely fresh. PM spreads so fast, its nearly impossible to contain without harmful fungicides. When I say start fresh, I mean removing everything. Don't leave any leaf clippings or any kind of plant material spores could infect. Then sanitize and start some new seeds.
Have you thought about a sulfur burner? You cant run it in flower but they're very effective in veg or to help sanitize your room. I'm in the northeast, on the coast and when the weather changes, I'm going to start running a burner for a couple hours periodically in veg.
I got the burner and the sulfur prills on amazon for around 50-60 bucks.
 
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Skoal

Well-Known Member
PM is terrible. It thrives in low temperature and high humidity conditions. If you are growing in a basement like me I usually run a heater hooked up on a thermostat in the tent or in the room. I prefer in the room since I have 2 tents. Increases ambient air temperate which allows the tents to increase temperature when lights are off. You want the plants not to be crowded as well. Also you can spray with hydrogen peroxide mixed with water. Anytime I get PM it’s usually near the bottom of the plant on the lower leaves that are crowded with a lot of growth. Trimming and opening up the bottom allows for better air flow. But keep those temps up at the end of the day. Seems to only happen in winter for me.
 

Bourbon 2

Well-Known Member
PM is terrible. It thrives in low temperature and high humidity conditions. If you are growing in a basement like me I usually run a heater hooked up on a thermostat in the tent or in the room. I prefer in the room since I have 2 tents. Increases ambient air temperate which allows the tents to increase temperature when lights are off. You want the plants not to be crowded as well. Also you can spray with hydrogen peroxide mixed with water. Anytime I get PM it’s usually near the bottom of the plant on the lower leaves that are crowded with a lot of growth. Trimming and opening up the bottom allows for better air flow. But keep those temps up at the end of the day. Seems to only happen in winter for me.
Actually the pm that I've noticed is on the top fan leaves, nothing under the canopy. Which suggests that the spores are airborne and getting in the room as I have the door open. If its humidity or temperature related as in earlier grows I'd see it deep in the canopy. I used to remove my shoes when I walked in the grow room but after multiple foliar applications the panda film is no longer sock friendly, lol... I'll take some shoe covers home with me tonight from our Cleanrooms at work :hump:
 

Skoal

Well-Known Member
Actually the pm that I've noticed is on the top fan leaves, nothing under the canopy. Which suggests that the spores are airborne and getting in the room as I have the door open. If its humidity or temperature related as in earlier grows I'd see it deep in the canopy. I used to remove my shoes when I walked in the grow room but after multiple foliar applications the panda film is no longer sock friendly, lol... I'll take some shoe covers home with me tonight from our Cleanrooms at work :hump:
Sorry to hear bro. Yeah mine is never on the top. I also do deep cleans all the time. I never leave my door open. Try to keep the hear up in my room. Getting rid of the spores will require a full clean of your room and tents. Spores can be anywhere. Floors. Walls. Ceiling. Etc.
 
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