Darn Powdery mildew

Seeing this stuff is quite disappointing. I noticed it about a week ago on my outdoor plants. First thing I did was remove a bunch of lower branches and infected leaves then wipe down each leaf with a cloth soaked in peroxide then spray the plant with a 1:4 peroxide to water solution.
The PM started appearing a few days later but not as bad.
This time I tried spraying some compost tea, thinking the bacteria would stop the mildew, it helped a bit but it keeps coming back. since then I'm simply pulling infected leaves off and disposing of them far away.

What can I do next? I'm not sure if I should just keep pulling leaves off or spray something stronger. The buds are forming nicely and I would love not to have to spray any chems on there.
From reading about PM, seems like I could spray with peroxide or baking soda solution.

Any help on the subject would be appreciated.

pic


Today I have removed a whole bunch of lower branches and as many infected leaves as I could spot as well as a lot of large overlapping fan leaves. I have sprayed a peroxide solution again.

Would it be a good idea to get some Potassium bicarbonate to spray with?

I definitely need to figure out how it happened in the first place.
Everything was going fine in veg.
This is an outdoor grow done in a diy green house.

1.) I did not prune enough
2.) lack of airflow due to not pruning
3.) something else I noticed today. See Pic
I noticed a tree that is about 10 ft away from the plants is covered in the mildew stuff. could the spores have come from that tree?



Here are some pictures of the greenhouse and plants. The left side wall is not normally on, we had a storm with high winds last night.

pic 1 ( normally like this with the window on the bottom screwed in place.)
pic 2 and pic 3 ( trimmed a bunch of lower branches today.)

.

Some other remedies I've come across:

9:1 water to milk, spray. Let milk sit out till warm.

Dr Zymes Eliminator.

CleanLight UV-C light

.

milk solution looks promising. Think its ok to use during flower?

Green clean works well

Caliverner said:

Green clean works well

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you plants must have the healthiest looking skin

thx ill try to find that

skoomaman said:

thx ill try to find that

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Good for bugs too

Potassium silicate foliar.

Stagnant air/lack of airflow will bring that pm out in no time. It is important to prune especially larger plants so those inside branches can breath. I would figure out a way to get those plants dancing in the wind ASAP. I had pm on my autos outdoors and hit them with Home Depot fungicide the first time it second application it was gone. I used the same stuff as a preventative for my photos & no pm in sight yet!

I had this same problem, my advice is don't use the chemicals. Figure out why it is happening.
@Renfro Taught me, Check your lights off Temp VS your light on temp.
Try to make them as even as possible.
Since I have installed a mini-split in my room my temps stay at 85 when the light is on and when they are off -/+ 2.
Due to it already being a breeding ground, the chemicals will kill it but you have to fix the source of the issue.
and Green clean works well but fix your temps first.

There are different types of PM but having a high humidity level is what causes it a lot of the time. Adding about 2 tablespoons of powdered sulfur per gallon of water is the best cure I’ve seen for it but I wouldn’t just go crazy and spray it all over a budding plant. It works so good I also use it indoors in veg now.

If you’re really wanting to save as much bud as possible and you have the time and energy, you could try like you did with the peroxide and wipe down every leaf with that sulfur mixture ASAP before your buds get too big, just try not to get it in the buds.

BTW wettable sulfur (sulfur powder) is really cheap and you can get it at Home Depot, Menards, etc for like $5-10. I guess you could try dusting it too but I’d wear a nuisance mask.

I’ve had PM almost every time I grew outdoors before I started using sulfur and it’s really just doing damage control until harvest because it won’t really go away. I’ve had a lot of luck with peroxide, baking soda and neem but it’s something you have to do almost daily until harvest.

My apologies in my head IDK why I thought this was indoors, and it is clearly in the outdoor forums.

Sorry

Motorbuds said:

There are different types of PM but having a high humidity level is what causes it a lot of the time. Adding about 2 tablespoons of powdered sulfur per gallon of water is the best cure I’ve seen for it but I wouldn’t just go crazy and spray it all over a budding plant. It works so good I also use it indoors in veg now.

If you’re really wanting to save as much bud as possible and you have the time and energy, you could try like you did with the peroxide and wipe down every leaf with that sulfur mixture ASAP before your buds get too big, just try not to get it in the buds.

BTW wettable sulfur (sulfur powder) is really cheap and you can get it at Home Depot, Menards, etc for like $5-10. I guess you could try dusting it too but I’d wear a nuisance mask.

I’ve had PM almost every time I grew outdoors before I started using sulfur and it’s really just doing damage control until harvest because it won’t really go away. I’ve had a lot of luck with peroxide, baking soda and neem but it’s something you have to do almost daily until harvest.

Click to expand...

I have the agricultural elemental sulfur (90%), that the kinda sulfur you're talking about?

I've used potassium bicarb, it's cheap and works relatively well.

Does the foliar sulphur stink after application?

I use greencure (potassium bicarbonate) and will be using LABS for the first time this season to see what it can do for PM. Also, if you can, get rid of the PM on that tree nearby, I remember on youtube hearing that this guys greenhouse was getting PM and it slowed down or stopped completely when he looked around and found a whole bunch of plants with PM on it nearby