Please, I am desperate for answer as we have no idea what to do anymore. We have been growing in the same space for about 5 years, using the same method, and have proper airflow and ventilation. Really nothing has changed except that we're dealing with powdery mildew. I posted months ago about discovering PM on our flowering plants. We sprayed with Actinovate and did a peroxide was when we trimmed. Everything turned out fine. Now, our plants are in veg and almost ready to go into the grow room and we're seeing the beginning signs of PM. What can we do? We can't turn the lights off to spray with Actinovate (or can we?) and we want to keep it organic. Ideas? Please, we are open to trying anything and I would love to hear everyone's suggestions. Thanks!
Do you have an hygrometer (humidity meter) if you are over 55% mildew can form up, otherwise the spores won't work, I've heard using ½ teaspoon baking soda per quart of water sprayed on leaves work..
Dehumidifiers, more fans, more fans, and deep clean of EVERYTHING with heavy bleach solution. At this point the PM is probably inside the plant tissue, so the dreaded Eagle 20 might be your only route to get rid of it. I personally would toss the plants and clean clean clean, PM is super dangerous to smoke and causes bad growers karma to those who sell it to patients. Bham Sent from my iPhone using Grasscity Forum
I've been having the same problems myself. Been trying various things, now, another. Seeing the mention of garlic extract could be effective, (no $) may try some kind of garlic tea next. If it goes well, will post an update. http://www.mandalaseeds.com/Guides/Marijuana-Mildew another link: \tPowdery Mildew
This is typical of many growers in temperate climes, easy over 50% of growers here and elsewhere have the same issue as you, I get a visit from the Pm angel at least 2x times per year, early spring and late fall, and as a result urge you to become a fungi master ..lol My best natural defense is regular applications of Neem Oil, 2-3 times per week by adding 1 teaspoon to a pint spray bottle, fill with warm water shake and spraysecond is to reduce the amount of water drastically in your grow space, give the plants the minimum to live on, and increase ventilation, remove all that dust/dirt, away from the intake, even plants, and stuff. For the plants that are infected, you must cut them off, very careful not to spread the spores about, be serious here, loose spores is dead canna plants. Those that are affected but not big enough to cut away, I like to put the pot or lower section of the plant in a trash bag, then invert(tip) the foliage into a warm bath(65f max) of water and 10% household bleach, that immediately turns any Pm to mush ....worth the picallow to dry in a windy place for 1-2 hours, consider washing down the walls also with hot water and bleachalso Neem Oil has been proving to be systemic, the plant drinks it up, thats great news, as it offers the plant great fungi/mold protection toogood luck