Hey everyone. Starting to see some powdery mildew set in on some plants. They are flowering. Any tips? I know the humidity in the greenhouse has been an issue.
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UGH! I feel ya bud shit just hit me up too. It went from too hot and humid to cool and humid way to fast + rain so the PM just creeped up on me regardless of sulfur treatment + additives throughout the growing season to increase resistance.
I ended up wetting the plants down, and stripped off all major fan leaves, then spraying down with H202 (3%) an hour before sundown so they got low angled sun rays to dry things off before the the sun set. My attack was extreme but i’d rather try this than deal with over a month of battle-stress like last year.
Before:
After:
I know I stressed out the plant but as I said; not gonna deal with last year again.
There are no more hiding spots anymore; so i can address issues as fast as they come. (i hope)
You can through the plants in all directions so sun and wind pass through no problem. It’ll also make it faster to use the leaf blower in the mornings to help get rid of the damp if it’s a wet sept. I’m in this until early Oct so 
.
Wishing you the best @hewhocoruptz .
(edit: I also gave them each a dose of castings tea while telling them I’m sorry for the tough love).
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Yes, that nasty September mildew. I feel your pain @hewhocoruptz and @Pigeonman
@hewhocoruptz if you dont already have one in there, an oscillating fan would really help, as well as clearing out some of the dense inner growth, if possible. This far into flower, the only thing I consider spraying with is hydrogen peroxide (diluted) or if you can get some potassium Bicarbonate, that would really help. Even then, it has potential to come back, if it’s an aggressive form of mildew. Yours looks fairly mild, so it should be fine with a couple sprays and reducing the humidity.
Hope this helps 
best wishes
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Thanks. I have some dr.zymes that I used for aphids last year so I might try some of that too. I know @gramps is a big advocate
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Yeah I definitely need to defoliate.
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There are 4 fans in there. One ground level and the rest up top
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Neem oil with Castile soap works for me every year. I don’t grow without it. And you can spray neem in flower I stop around week 4 or 5.
The only PM I saw this year was on the MAC1 and it was just on one leaf. Sprayed it that day and never saw it again.
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Like others have said, more airflow. I would really try to keep your plants in vpd range as much as possible.
Imo you are in a bad spot being this early in flowering. I would make it my morning routine every day to take a little spray bottle and spot spray the bad spots with potassium bicarbonate. Be careful to not get it on the pistils, or you will burn them.
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Thanks man. Unfortunately I work during the day. I’m going there tonight to clear out the excess foliage. It’s on other plants also. We shall see how it goes.
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Late evening spraying would work just fine. 
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Right on. Any experience with hydrogen peroxide?
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I don’t, sorry.
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The DoctorZymes has worked for me 4oz to a gallon of water and spray at lights out or sundown it won’t harm the buds no stink no taste . if your just starting to bud sulfur will kill it I just don’t like using smelly chemicals on my smoke .
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Hi, I use diluted milk (1:10) sprinkled on the leaves. Works for beans, tomatoes and cucumbers.
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So I decided to go with 30ml hydrogen peroxide to 1 gallon of water after clearing a lot of foliage last night. Maybe for the other plants infected I’ll try some doctor zymes. I’ll keep this page updated. A little praying mantis action too!
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I just sprayed the greenhouse here in Michigan this morning for PM with 1 tablespoon per gallon organic potassium bicarbonate (half rate) “Green Cure” brand.
Wait a week see what happens, spray again if needed, potassium bicarbonate also treats Botrytis (bud rot) so it’s got the added bonus of being preventative for that as well. I always rinse my outdoor weed with lemon water (and sometimes a regular water rinse) when harvesting.
(Only recent pics I have)
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Right on man. This will be a good place to see what works.
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Do you have PM or preventive?
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Started getting (or at least noticing) baby spots of PM about a week ago but have been too busy (and depressed unfortunately) to find the motivation to fill up the electric backpack sprayer (none of it was difficult lol). Still hadn’t spread much when I looked at it 2 days ago and it was a downpour last night so I sprayed at 545am before I left for work.
I’ve had PM in Michigan since I started growing when I got my house 3 years ago, usually around this time of year sometimes during summer if it rains too frequently but the cool temps seem to really bring it out. I also haven’t defoliated at all this year, tons of lollipopping but I try and do so much at once I can’t find the time or energy for it all, it’s on my list for this weekend so they can breath n get light better for the rest of flower.
Probably pushing real close to my 5 week limit of fucking with things in flower
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Right on. I’m in michigan too but this is my first bout with pm. I need to be more pro active with ipm strategies in the future. The greenhouse game ain’t a joke.
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