Thats why you gotta be weary of what your companion planting

Have you tried spraying with neam oil? I heard that helps? Caveat empator, I don't know much about horticulture.

I agree, do you think it's likely that the PM jumped from the squash to the cannabis? It is planted in the food forest about 150ft away from the cannabis garden. I think the problem is more so with the specific plant. The others in the garden have no issues but this plant was covered. It might be the way it grows more bushy and with lots of overlapping fan leaves while the others are more spread out. Maybe this plant is also just susceptible to powdery mildew, something in the genetics?

I've had luck with water & milk, 50:50 against powdery mildew. it lives in the soil too. just a few applications and you'll see an improvement. why let it spread?

When do you apply?

Ill have to try this. I had a lot of powdery mildew this year on my plants. I’m thinking it’s genetics since I’ve been reusing seed for several years and the mildew is getting worse every year.

when I see it starting. because I'm not sure how effective it is as a prophylactic... also, I usually forget. :) cukes got it bad one year & spread to my comfrey. mixed up a half gallon milk with half gallon of water... sprayed the leaves liberally, soaked the soil around the plants. did it again a few days later. didn't have any sign of it this year, but I can't say for sure it lasts.

I forgot to say, leave the milk out overnight. it's those bacteria that eat/fight/kill the PW... or so I've been told. I guess my battle with it has gotten better over time. just now realizing that. it was a few years ago that I had it bad. last couple of years, there has been any, and we had a cool wet summer in central ny.

correction *hasn't been any in the last couple years.

I'll keep it in mind for next year. Thanks for the tip! I'm sure others can get a lot out of the information too.

I would do it now. whatyagot2lose?

Ill keep in mind for next year. Everything is harvested for this year. Maybe I should spray the ground to be sure. We have raw milk, hopefully that works even better.

it is used as fertilizer. but like anything, start with a little and add as you go. too much of a good thing can be bad. saturated soil on a warm day might get funky.

Spores are almost everywhere. That cool stretch in August lowered the dew point and made the right environment for PM. It's very hard to control PM once it happens, and I don't like the idea of foliar sprays once the buds are 3-4 weeks into flowering. It's very likely that cross contamination happened from other more vulnerable plants in the garden, but the other half is that some varieties are more susceptible. I've seen different phenotypes from the same lot of seed where some are resistant and some susceptible. My thought is it's easier to let's some go to the compost pile than trying to manage it. You can't control the outdoors, so it's always going to happen to some degree.

Calcium and silica rev.hodl been a persistently awful summer here so I have been battling it all season. 😭 I have been using potsil and water soluble calcium as a foliar (diluted crushed egg shells in cider vinegar as a foliar spray) which works well when used consistently. However for next years potential grey weather I am starting to gather horsetail (equisetum arvense)for an fpj as looking at it's mineral profile it has boat loads of both which should prevent the mildew from forming.