Help! Powdery Mildew?

[Doug58]

Hit them with potassium bicarbonate last night but may have went a bit light. Was afraid of getting the buds too much. That coupled with rain makes me think it didn’t work fully. Do you know how often plants can be treated?

Growtogrow posted daily. I've only done it once so far after rainy days with no sun and high humidity. Since that day last week it has been windy, cooler in the 70's and stopped raining. I used 1 tablespoon in a one gallon pump sprayer and sprayed it over my plants completely soaking them. I haven't noticed any ill effects. I'd do it early in the morning or just before sun down if it is going to be a sunny hot day because water alone soaking leaves in full sun can cause problems. I've sprayed water in full sunlight on a hot day and caused wilting leaves.

 

[cubfaninmo]

Growtogrow posted daily. I've only done it once so far after rainy days with no sun and high humidity. Since that day last week it has been windy, cooler in the 70's and stopped raining. I used 1 tablespoon in a one gallon pump sprayer and sprayed it over my plants completely soaking them. I haven't noticed any ill effects. I'd do it early in the morning or just before sun down if it is going to be a sunny hot day because water alone soaking leaves in full sun can cause problems. I've sprayed water in full sunlight on a hot day and caused wilting leaves.

Cool. Do you soak buds also? I’m at day 65.

 

[Doug58]

I spray the entire plant. Powdery mildew, if you have it, can spread over the entire plant. I grew a big photo plant last year that had about a pound and a half of buds, powdery mildew and bud rot started spreading from the bottom after I had harvested about a half pound. I sprayed it with H2O2 every day once I noticed it. I lost some of the largest buds that were as long as my forearm and as big around as a 24 ounce beer can.

I finished harvesting and washed all the bud in H2O2 wash after breaking the buds down and cutting out bud rot. It will spread fast if you don't control it. I never tried milk as I don't buy milk usually. Others have said the use H202 to spray on their plants but that potassium bicarbonate is more effective.

I was able to save all but 1/2 a pound from the photo plant last year. I completely opened up the lower part of the plant and had harvested it by sections over a week and a half. It rained for the final 7 days and I never saw the sun. Everyone was having PM and bud rot problems in my state last year because of weather.

 

[cubfaninmo]

I spray the entire plant. Powdery mildew, if you have it, can spread over the entire plant. I grew a big photo plant last year that had about a pound and a half of buds, powdery mildew and bud rot started spreading from the bottom after I had harvested about a half pound. I sprayed it with H2O2 every day once I noticed it. I lost some of the largest buds that were as long as my forearm and as big around as a 24 ounce beer can.

I finished harvesting and washed all the bud in H2O2 wash after breaking the buds down and cutting out bud rot. It will spread fast if you don't control it. I never tried milk as I don't buy milk usually. Others have said the use H202 to spray on their plants but that potassium bicarbonate is more effective.

I was able to save all but 1/2 a pound from the photo plant last year. I completely opened up the lower part of the plant and had harvested it by sections over a week and a half. It rained for the final 7 days and I never saw the sun. Everyone was having PM and bud rot problems in my state last year because of weather.

Looks like rain again so I’ll hold off and see what the weather is like tomorrow. Looking again, it may have done a better job than I thought this morning. Only noticeable difference is the pistils didn’t appreciate it

 

[Doug58]

Cool. Do you soak buds also? I’m at day 65.

Wash your buds at harvest with an H2O2 solution after cutting off all fan leaves and doing an initial trim of the outer sugar leaves. Then rinse in just cool water. Shake dry and hang to dry. After a couple days put buds in brown paper bags.

 

[Doug58]

Get yourself one of those 60x-120x Carson led lighted pocket microscopes from Amazon so you can really get a look at your trichomes on your next grow. They are less than $15.00, I bought one last year and it made it easy to see the amber trichomes I could never focus on with a 60x lighted jewelry loop. You can then more easily judge when it is the correct time to harvest.

For bud washing after harvest just Google it for the correct amount of H2O2 per gallon of water. I also used a lemon juice, baking soda wash with rinse. I didn't do this with my first couple of autos harvested last year but once I started using a wash I won't smoke my own homegrown from outside again without doing it. My plants grown outside get covered with dust, pollen from numerous trees and bug and bird crap.

Once washed, dried and cured I couldn't believe the aroma from inside the jars from different strains. Instead of the smells of weed I have berries, pine, spices and endless good smells. I don't even recognize the smells of marijuana I was used to.

 

[Gone Camping]

I sprayed my plants with a pump sprayer today with 1 gallon of well water with a tablespoon of potassium bicarbonate.

Mix 4 teaspoons (about 1 rounded tablespoon) of potassium bicarbonate into one gallon of water. Spray lightly on foliage of plants afflicted with black spot, powdery mildew, brown patch and other fungal diseases.

Potassium bicarbonate– Similar to baking soda, this has the unique advantage of actually eliminating powdery mildew once it's there. Potassium bicarbonate is a contact fungicide which kills the powdery mildew spores quickly. In addition, it's approved for use in organic growing.

1 pound for $8.99 at Amazon.

You can try H2O2 mixed with water in a pump sprayer but I would go with potassium bicarbonate. Growtogrow mentions it in his outdoor grow thread.

I experienced PM last run, first for me. The water/milk worked better than the water/h202 followed by a wash at harvest.

Gonna order some of this, thanks for that. Also read about UV lighting, but need to read up some more. My room has been shut down for months, allowing to heat over 100* for a week before a good bleach and water cleaning.

 

[Bob's Auto's]

Nothing beats a good clean with bleach now and then. Just don't use it on you buds, bud

 

[Doug58]

I experienced PM last run, first for me. The water/milk worked better than the water/h202 followed by a wash at harvest.

Gonna order some of this, thanks for that. Also read about UV lighting, but need to read up some more. My room has been shut down for months, allowing to heat over 100* for a week before a good bleach and water cleaning.

I do the wash at harvest to get all the crud off of the buds, I make edibles and I don't care to eat bugs, bird and bug crap, dirt. I must have counted 20 different type of bugs on my plants this week. I don't spray my weed with insecticides. I have picked off caterpillars, ants stuck in sap, spiders, beetles of some type, grasshoppers, earwigs, flies of some type, gnats, slugs. All kinds of critters. I also have little red squirrels, mice, voles and chipmunks who invade my outdoor grow area.

I also have an untold number of toads of all sizes. I let them live there unmolested. I have even seen them up in my pots digging from time to time. I let them exist as they eat huge amounts of bugs every day. Toads will also eat field mice. I have taken toads I find out on my yard and relocated them to my grow area.