Is this white powdery mildew?

Almost at the end of my first run. Was trying to grow medicine for a good friend. Was doing a little defoliation and noticed what appears to be white powdery mold or mildew not sure if thats what im seeing or what to do about it. Super dissapointed :disappointed:. It only appears to be on one plant and only towards the bottom of it on less matured bud leaves. Any and all suggestions would be appreciated :pray::pleading_face:

Hope the pictures are clear enogh

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Are you using an ultrasonic humidifier with tap water? Mineral dust from an ultrasonic humidifier is frequently mistaken for WPM.

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No actually not using a humidifier at all. Was using a dehumidifier but havent needed it in a while. Humidity is hovering around 30’s - 40% ish

Not sure if i should remove it from the tent? Or if it will spread to other plants

WPM is pretty easy to treat. Give the plant a spray with diluted hydrogen peroxide. It will kill the mold pretty quickly. I use a dilution ratio of 50/50.

WPM can be caused by high humidity and lack of airflow. Suggest a dehumidifier if your humidity is too high (>50 in flowering) or simply increasing the airflow in your grow space with a fan or 2.


Is that definitely what it is? Should i just spray the affected areas? Spray liberally?
Thank you :pray: by the way.

Hey @Noobydoobie i would spray the whole grow and tent area. That powder can be spread all around. Even when your humidity is low the respiration from your plants will give it a foothold.
Exhaust fans should be running full time refresh air constantly. Your tent fan(s) need to be running also to help keep the leaves dry during lights out as well.


That does look like Powdery Mildew. Definitely spray your entire garden. Increase your air circulation or thin out crop.

What is your humidity at nighttime? What are your temps, both high and low? What do you use for air circulation?

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My humidity is around 35 - 45 % have multiple oscillating fans running 24/7. And an exhaust fan. High temperature is around 78 and low is about 65ish. Spray the whole plant with 50/50 water hydrogen peroxide mixture? Supposed to harvest shortly will the spray effect anything ?

Peroxide mix won’t hurt the plant u wanna avoid spraying oily pesticides and stuff on the buds as the oils stick and alter flavors. Peroxide will take it away but if not a good airflow going thru the plants and lower rh it will come right back and quick. If u struggle with wpm in the room grab u a bottle of blue magic it works awesome against wpm and if mixed right or a touch stronger than recommended it took away the pm and kept it away here after one spray. Seriously great stuff just a little pricey. It does contain soybean oil but is safe to use til day of harvest and all. It’s like a 100 a little for it but works great


Thank you brother much needed advice and much appreciated :pray: