Hey everyone,

So I have a handful of plants outdoors, planted in ground, that are, by the looks of it, about midway through flowering.


I have been starting to notice PM (powdery mildew) on the leaves, starting a few weeks ago. The last week or 2 the the amount I am finding has been going up. So far, I have just been removing the leaves and trying to take them out of the area with as little jostling as possible.

Any solutions for suppressing or eradicating PM and/or other mold issues (botrytis etc) during flowering would be greatly appreciated. I haven't found much bud rot yet ( just what looked like a little bit on one or two little buds which I removed) but given my environment , where we tend to have cold, wet autumns , I am expecting to have at least some bud rot and alsoo expect this PM will be getting worse... Unless I can find a way to curb it.


In order to keep this post from getting to long winded I will leave it at that but I will update with pictures and with what I have given them thus far.


Thanks folks!

I found a product called Green Cure that is made of potassium bicarbonate. It's nontoxic and safe to use on flowering plants. It has worked well for me.

It's hard to prevent PM outdoors because you can't control the humidity or the wind. Some strains are more prone to get PM, so avoiding those will help.

iirc there is a sulfur based folliar spray you can use to remedy PM

check this article
https://www.farmprogress...trolling-powdery-mildew

also this one is more geared towards cannabis
https://oaksterdamuniversity.com/5598-2/

Late to the party, I guess. But I want to add my knowledge to the thread for future reference. I am a former professional cannabis farmer, indoors and out.

Sulphur Burners, as they are called, work well in greenhouses and indoor grows if you get them dialed in right. It is a preventative measure. Another suggestion that I would make is using a product called Actinovate. It is OMRI listed and works very well. If you have a bad situation, a heavy spray and then raise the humidity up as high as you can for 24-36 hours. It works very well. Actinovate also functions reasonably well as a part of your preventative schedule.

Remember: PM is more than just a mold on the leaf surface. It is in the plant itself. Clones from a plant infected with PM will have PM problems if conditions are right. The best plan is clean cutting from plants not already infected, or tissue cultures off you have cultivars that you simply can not substitute.