My experience with powdery mildew

Clink78

Well-Known Member
Hey folks,

Just wanted to give my 2 cents about PM. I’m not a scientist so this is simply my thoughts from growing outdoors all these years.

PM… fuck you. Of all the plant afflictions, this is definitely the worst. Rot is often localized on one or several buds, but you can generally harvest most of your plant intact. PM is different. Once you have it, it will spread everywhere.

The good news is that it is very strain specific. I’ve had different strains in one garden and one plant would have it all over while the plant next to it (and I mean super close) was completely free. Therefore choosing your strain is important. When you find one that is PM free for several years, stick to it.

Now I know a lot of people try to treat their plants once PM appears, and that’s a personal choice. Personally, I’ve treated in the past and it may have worked in the sense that I did not see the PM anymore, but there was always a doubt in the back of my mind and because of that it affected the whole experience. I also noticed that by treating the plant, the taste and smell were changed. Or were they? Again, doubt.

So now if I find PM and I’m sure that’s what it is, I get rid of the whole plant. I tried a new strain last year and lost all my plants. This year‘s strain is a go, no PM at all.

Anyway those are my thoughts, happy harvest everyone!
 

dakilla187

Well-Known Member
I use lost coast therapy once or twice a week from veg before pm is present and dont get any pm at all on any strain....
 

obijohn

Well-Known Member
I always struggle with budworms and bud rot (but keep it managed) but have never had PM, even tho it sometimes is humid enough late fall to cause budrot without budworms. It may well be strain specific, or the outdoor conditions here in Nor Cal
 

SmichiganOG

Well-Known Member
I always struggle with budworms and bud rot (but keep it managed) but have never had PM, even tho it sometimes is humid enough late fall to cause budrot without budworms. It may well be strain specific, or the outdoor conditions here in Nor Cal
I don't consider PM a big problem. Bud rot sucks. So does septoria.
 

Dark_Hatchling

Well-Known Member
I always struggle with budworms and bud rot (but keep it managed) but have never had PM, even tho it sometimes is humid enough late fall to cause budrot without budworms. It may well be strain specific, or the outdoor conditions here in Nor Cal
Question for you sir (I'm in the same area): What do you use for your IPM?
 

Rurumo

Well-Known Member
Optimal conditions for PM in studies are low 70's temps and 45% RH. Most studies actually see a reduction in PM as RH % increases. Makes sense, I see PM develop on my pumpkins every fall in those conditions. Botrytis is also my main concern indoors/out, but PM can be nasty once it infects a space, prevention is key, as others have said above. I've never gotten PM on a plant that I treated with bacillus amyloliquefaciens (the Montery product above, or Southern Ag Garden Friendly Fungicide, or Tribus.) It's the single most all around useful of the common rhizobacteria sold. I add it to my weekly neem spray during veg.
 

obijohn

Well-Known Member
Question for you sir (I'm in the same area): What do you use for your IPM?

Past few years just Spinosad. It gets rid of pretty much everything bad, I've even seen exploded budworms in the past. I do have BT, but doesn't seem necessary, plus it is only good for a few days after spraying, Spinosad's effects are good for a few weeks so need need to spray every few days
 

SmichiganOG

Well-Known Member
Optimal conditions for PM in studies are low 70's temps and 45% RH. Most studies actually see a reduction in PM as RH % increases. Makes sense, I see PM develop on my pumpkins every fall in those conditions. Botrytis is also my main concern indoors/out, but PM can be nasty once it infects a space, prevention is key, as others have said above. I've never gotten PM on a plant that I treated with bacillus amyloliquefaciens (the Montery product above, or Southern Ag Garden Friendly Fungicide, or Tribus.) It's the single most all around useful of the common rhizobacteria sold. I add it to my weekly neem spray during veg.
I used Copper in veg this year and I always use potassium silicate. Last year I used chips as mulch and later learned it's bad (promotes it) for fungus. I used hay this year. Not sure that's any better but I had less fungus. I always spray fungus microbes and bt. This year I got lax near the end of season.
 

SmichiganOG

Well-Known Member
Past few years just Spinosad. It gets rid of pretty much everything bad, I've even seen exploded budworms in the past. I do have BT, but doesn't seem necessary, plus it is only good for a few days after spraying, Spinosad's effects are good for a few weeks so need need to spray every few days
I'll have to try It.
 

Dark_Hatchling

Well-Known Member
Past few years just Spinosad. It gets rid of pretty much everything bad, I've even seen exploded budworms in the past. I do have BT, but doesn't seem necessary, plus it is only good for a few days after spraying, Spinosad's effects are good for a few weeks so need need to spray every few days
Yes, I use Spinosad too. It seems very effective for worms.
 

Wizzlebiz

Well-Known Member
Question for you sir (I'm in the same area): What do you use for your IPM?
I live near Fairfield. I removed all vegetation within a 30 foot radius of my plants and use neem during veg and BT during flower.

I always get ladybugs and preying mantis sacks for each plant. Biggest issues here are aphids and caterpillars.

BT for the caterpillars and close inspection daily for aphids. If I see any aphids I'm putting on some rubber gloves and killing everything I can see by squishing with my fingers.

Outdoor growing is not easy to keep clean.
 

FinnWinn

Member
Hey folks,

Just wanted to give my 2 cents about PM. I’m not a scientist so this is simply my thoughts from growing outdoors all these years.

PM… fuck you. Of all the plant afflictions, this is definitely the worst. Rot is often localized on one or several buds, but you can generally harvest most of your plant intact. PM is different. Once you have it, it will spread everywhere.

The good news is that it is very strain specific. I’ve had different strains in one garden and one plant would have it all over while the plant next to it (and I mean super close) was completely free. Therefore choosing your strain is important. When you find one that is PM free for several years, stick to it.

Now I know a lot of people try to treat their plants once PM appears, and that’s a personal choice. Personally, I’ve treated in the past and it may have worked in the sense that I did not see the PM anymore, but there was always a doubt in the back of my mind and because of that it affected the whole experience. I also noticed that by treating the plant, the taste and smell were changed. Or were they? Again, doubt.

So now if I find PM and I’m sure that’s what it is, I get rid of the whole plant. I tried a new strain last year and lost all my plants. This year‘s strain is a go, no PM at all.

Anyway those are my thoughts, happy harvest everyone!
Have you looked into silica in the root zone? I read an article about silica in the root zone preventing p.m. something worth looking into. I also had a bout with p.m this year so I'm looking into this for next year.
 
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