Powdery Mildew spots showing on fan leaves

Outdoor balcony 3rd floor....Noticed some white powdery mildew spots only on my Purple Alien OG. A couple fan leaves have it and some of the sugar leaves have it. I am so close to harvest. Is it ok to mix baking soda with water at this point in the game or should I just chop it within the ned few days.

I haven't used the baking soda method so I can't comment on that. I experimented with a lot of different remedies last year and eventually settled into diluted H2O2 sprays and Actinovate as my favorite treatments. I don't use them together because Actinovate, like Serenade, is a bacteria based solution and I could not determine if the H2O2 kills them.

So I would pick off the spotted leaves, spray everything with diluted H2O2 solution, and then after that dries come in and spray and drench soil with Actinovate. This is a safe treatment plan for late flowering. Dilution rates for H2O2 can be found at this site:

http://www.using-hydrogen-peroxide.com/gardening-with-hydrogen-peroxide.html

You should also research the H2O2 bath and rinse method for harvest if you still have PM on your buds.

That's my 2 cents, good luck!

Bugeye said:

I haven't used the baking soda method so I can't comment on that. I experimented with a lot of different remedies last year and eventually settled into diluted H2O2 sprays and Actinovate as my favorite treatments. I don't use them together because Actinovate, like Serenade, is a bacteria based solution and I could not determine if the H2O2 kills them.

So I would pick off the spotted leaves, spray everything with diluted H2O2 solution, and then after that dries come in and spray and drench soil with Actinovate. This is a safe treatment plan for late flowering. Dilution rates for H2O2 can be found at this site:

http://www.using-hydrogen-peroxide.com/gardening-with-hydrogen-peroxide.html

You should also research the H2O2 bath and rinse method for harvest if you still have PM on your buds.

That's my 2 cents, good luck!

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Thank you very much.

I can vouch for both the diluted h202 and baking soda method, my area is terrible for PM and have tried both. Now since I know it's in the air here, I use the baking soda spray solution (with Olive oil and soap) in veg and have been able to keep it from coming back. I originally brought it indoor from a fresh air vent, took months to eradicate, nasty stuff.

GroErr said:

I can vouch for both the diluted h202 and baking soda method, my area is terrible for PM and have tried both. Now since I know it's in the air here, I use the baking soda spray solution (with Olive oil and soap) in veg and have been able to keep it from coming back. I originally brought it indoor from a fresh air vent, took months to eradicate, nasty stuff.

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I agree, used both and happy with it

Potassium bicarbonate is the most superior of all the organic methods. get some greencure. its 15 bucks and will last a looong time

thegreensurfer said:

Potassium bicarbonate is the most superior of all the organic methods. get some greencure. its 15 bucks and will last a looong time

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I've seen references to that and tried to find it but was difficult to find here (Canada), ended up trying milk, the baking soda and h202, both the last 2 work well so stuck with them, I used milk in very late flowering with only like 1 week left, it seemed to keep it at bay but only lasted a few days before having to re-spray . The stuff is nasty, and some strains are really susceptible to it, while others almost shrug it off. I'm trying to stick to strains that can handle some of it, not that I'll be inviting it indoor and I've cut-off the inbound air vent, but it seems to travel easily so you never know. Once I finally got rid of it indoor my f'n outdoor plants got it late summer, been spraying them weekly and it's under control though $#%!

I think finding a resistant strain is the best option considering its everywhere around us, especially in areas with larger day/night temp fluctuations.. .
Blue dream is resistant in my experience, as is every cross I ever made with it. Try amending with silica...potassium silicate if I remember correctly. It aids the plant cell strength which makes it harder for a spore to germinate on the leaf. Starting from seed helps too
I'm not really convinced of the milk treatment, especially when most are using western pasteurized milk.
Once the pm starts to creep into the buds it becomes very hard to manage.

Pm is a tough thing to fight. I've found that controlling humidity helps. The higher the humidity gets the more the pm seems to take off. Nasty Stuff!

Agree, to a point though, you don't want humidity too high as it's probably more susceptible. But I have a veg cabinet that I run fairly high RH and I'm in an area where there high humidity, the humidity in that veg cabinet has been 65-70%+ all summer and no PM in there. Lots of airflow etc. probably helped and is good. But the almost sure-fire way to get it indoors is to allow it in from outside, I don't think it can just pop up indoor unless it exists in your area (could be air, clones, plants, whatever is brought indoor bearings it in). My issue this past spring was I didn't realize how bad it was in my neighbourhood and I was bringing in fresh air to cool my room. Now that I've re-designed the airflow and don't directly bring in outside air (I get air from my furnace/air conditioner that's been filtered with an electronic furnace filter, then a filter in my inline fan before bringing it into the room) it's under control, at least indoor. But my outdoor plants got it and I've been fighting it all summer outside, nasty for sure.

My go forward is staying away from certain strains like that Platinum Bubba Kush that is a PM magnet, eliminating outside air directly into the grow rooms, no outside plants/soil brought indoor, spraying the plants in veg every couple of weeks as a preventative measure, and lots of airflow. Seems to be working well so far... fingers crossed. Took me a couple of months and culling a few plants/clones/seedlings to get rid of it this spring

MedgrowerCO said:

Pm is a tough thing to fight. I've found that controlling humidity helps. The higher the humidity gets the more the pm seems to take off. Nasty Stuff!

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There's not much humidity where I live.. So I am not sure how it sprung up on me.

From my exp I just noticed that it seems to thrive in moist conditions.
I think pm is in the plant systemically so it gets passed thru clones. I know I'm guilty of taking the easy way out and getting cuts from friends that have done the work of planting the beans and sorting them out.

1/2 cup h202 mixed in a quart spray bottle of water...hit it as you see it daily in the day time so the buds can dry

Pm is a airborne spore or you have received a cut that has pm inside the plant already

one dose of Eagle 20 in veg will cure any cut with pm

Kill it. Do not smoke mildew. At the least it will make you sick, if you are already sick it could kill you. I have heard of ppl making butter with it.

Black Cough said:

Kill it. Do not smoke mildew. At the least it will make you sick, if you are already sick it could kill you. I have heard of ppl making butter with it.

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Cite your sources please. Sounds like you are shooting from the hip and more than a little off base.

Maybe you have healthy lungs and you can deal with smoking mildew. If I even smell it I will start wheezing and coughing. When I have smoked bud in the past that was "tainted" I got a bad lung infection that I couldn't seem to shake. I knew someone with bad copd and smoking moldy bud (and cigarettes) and bad allergies led to him developing pneumonia and dying. 47 yrs old. He was my best friend. You might be fine and have no reaction to smoking it. But don't share it with anyone else.

Did your plants dew up in the morning?

Black Cough said:

Maybe you have healthy lungs and you can deal with smoking mildew. If I even smell it I will start wheezing and coughing. When I have smoked bud in the past that was "tainted" I got a bad lung infection that I couldn't seem to shake. I knew someone with bad copd and smoking moldy bud (and cigarettes) and bad allergies led to him developing pneumonia and dying. 47 yrs old. He was my best friend. You might be fine and have no reaction to smoking it. But don't share it with anyone else.

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It can be successfully treated and removed from the plant at harvest. If not, nobody is advocating smoking powdery mildew encrusted bud. Advising someone to kill their plant immediately because you and a friend smoked some poorly harvested buds is pretty overkill when a plethora of remedies are available to try first.

408BayShark said:

There's not much humidity where I live.. So I am not sure how it sprung up on me.

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Do you spray anything on the leaves or get them really wet when watering? Where did it start? The bottom or the middle or top? If its the bottom its from wild watering and if youve been spraying them with water for some odd reason that could be it too. Pluck the leaves and baking soda them. That works really well. Good luck.

Bugeye said:

It can be successfully treated and removed from the plant at harvest. If not, nobody is advocating smoking powdery mildew encrusted bud. Advising someone to kill their plant immediately because you and a friend smoked some poorly harvested buds is pretty overkill when a plethora of remedies are available to try first.

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Please tell me how to get spores out of flowers? My understanding is once they are present they spread throughout the whole plant. You can remove it from the leaves, but small amounts will remain in the bud.

I have plenty of respect for you bugeye, your setup is amazing, and I'll bet you could probably manage this problem. I am not willing to take chances with PM.....it's like ebola