Help. Is this white mould?


Please help first time grower. I have read about spraying plants that have white mould but have not found any procedure if I spray with baking soda, or apple cider vinegar, or milk and water do I spray entire plant or avoid buds or how much do I put. I am in Canada just north of Toronto and it is an outdoor grow of our allowed 4 plants. So far I see these small white spots on 2 of the plants but not really powdery. Please help.
Sept 7/2020

Is it possible to get a clearer picture?
Welcom to the community!

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Hi Covertgrower. Thanks for responding. I only saw the msg now and it’s too dark to take a clearer picture. I will do so in the morning. I really would appreciate input as this is our first time and we are freaking out a bit.

Well don’t do that, there’s plenty of help here. Lol. :grin:


seriously! Mellow… we are more than able to meet the challenge here. At least one of us will be able help for sure, plus cannabis is a pretty sturdy plant.


Hi again. Rained during night and windy and rainy again today. Are these pics better? If need more specific let me know. Thanks

Yes much better. I recommend hosing with the 3% peroxide solution, and when it rains shake off the excess water.

Ok. I haven’t read about a peroxide solution just baking soda/vinegar/or milk. And what do you mean hosing? Is there a written procedure somewhere explaining what we need to do? Do we avoid the buds? And how do we avoid it coming back? Do we need to trim leaves? Sorry for so many questions.

Sorry, spraying would be a better term than hosing. Milk works too, but leaves a film, just like baking soda. Both are effective, just leaves a residual film on the plant. The peroxide leaves the plant looking better.

I would recommend a thorough application of the entire plant. Flowers included. Hope that helps. No worries on the questions, that’s why we’re all here. Grower support. :wink:

Thanks for the fast response. Ok so what are the ratios for the peroxide? ( I assume it’s the one we have home). Do I treat all 4 plants? currently 2 on right hand side (N) are showing spots. Should I wait til tomorrow as rain forecasted for today? Also do we need to trim any of our leaves for prevention for reoccurrence?

I wouldn’t recommend trimming unless you see some damaged beyond being useful. Being outside you can lose a few leaves.
1:1 ratio is recommended to start out, you can work your way up from that. Yes the 3% peroxide.
Edit, missed the rain comment.
I would spray the next day after the rain. When you can, shake the excess rain off.

Ok. Thanks Covertgrower. I appreciate all your help. I assume I should do all 4 plants. Any advice on how to prevent this happening again now or for future grows?

It’s just about conditions. Some years are better than others. You can treat weekly with hydrogen peroxide next time, but that’s about all you can do. Outside has its challenges.
Tag me anytime, enjoy helping.
Happy growing! :seedling:

Hey. Me again. We sprayed yesterday and today it actually looks to me like there is more white stuff. Unless that is the peroxide. We sprayed about a litre of 1:1 solution on as I didn’t find any instructions. Should we be drenching the plant? What should it look like afterwards? Awaiting your advice. Thanks.

Try spraying direct peroxide on, all over thoroughly.

Ok. Thanks. Supposed to be sunny this afternoon. Is still ok to spray or do I wait til evening? Thoroughly…think I missed that in previous notes. Sorry

It’s it’s partial sun, or overcast, I would wait until just past mid afternoon, or before dusk. Just not direct sun is what I’m getting at.
No worries at all, happy growing. :seedling:

I too am having an issue with powdery mould. I started with milk and water and wasnt seeing results. So I bought 15999467118644483279463397657685|375x500 and we have been spraying twice a week for the last 2 weeks. I dont know if it is leaving a film or we still have mould?? Would you suggest I try peroxide and water? I’m about 5 weeks into flowering and getting really nervous about losing my beautiful buds!! Please help

I would highly recommend using hydrogen peroxide to kill mold. Welcome to the community. @777nicki

Thank you so much. How much peroxide per gallon of water. Will it hurt the flavor or potency of the buds. How often should I spray them?

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