How To Prevent Powdery Mildew In Cannabis

How to prevent powdery mildew

What is powdery mildew in cannabis?

How to prevent powdery mildew in cannabis. Powdery mildew is a common fungus that looks like white powder on your cannabis leaves. It thrives in moist environments and attacks plants in all stages of growth. In humid climates and during the rainy season, it’s not uncommon to see your plant get infected with this parasite. Fortunately, there are things you can do to prevent powdery mildew and the damage it causes. In its early stages, powdery mildew looks like white dust on the upper side of your leaves. The fungus will continue to grow spores until it covers most of the plant’s surface area. Leaves of infected plants are stunted, and they stop growing in length. Powdery mildew will eventually cover the entire leaf surface area, except for the veins. The powder causes yellow spots on your leaves. As more spores grow on your plant, it becomes increasingly difficult to tell where the original dust was.


How does powdery mildew spread?

The spores are spread through wind and water splashes, so it’s essential to identify the source of your plant’s infection. If you don’t take immediate action, the fungus will continue to grow on every part of your plant – stems, buds and all other leaves. Eventually, your plant’s immune system will become overwhelmed by the fungus and die. The good news is that there are simple steps you can take to prevent the spread of this fungus. Powdery mildew thrives in humid environments, so it’s essential to keep surrounding air as dry as possible. The easiest way is by using fans! Place a fan facing downward (towards your plants) and another one blowing horizontally (away from your plants). This will help prevent the air around your plants from getting humid. You can also use a dehumidifier to kill the spores that are starting to grow on your cannabis leaves. The best-case scenario is to catch powdery mildew before it spreads to other parts of your plant.

Cannabis grow guide

Preventing is the Key

Preventing powdery mildew in cannabis is the key solution. Having the dehumidifiers and fans working properly will greatly reduce the risk of spreading powdery mildew and having an air purifier in place. The most common symptom is the appearance of powdery spores on both leaf surfaces and in the air. Powdery mildew does not kill cannabis plants but it may weaken their immune system which could make them more susceptible to other fungal infections like Botrytis cinerea (which causes gray mold). As such, it is important for growers to remove infected leaves as soon as they spot them – by doing so, they will be able to prevent any further damage from occurring since there won’t be any spores left behind and help prevent other fungi from growing. An air purifier will remove any additional spores that are floating in the air around your plants.


Finding The Right Air Purifier Solution

Not all air purifiers are created equal. So to save you some time on your research, check out our YouTube channel AirROSbySAGE that will go over all the types of air purification technology and which one best work for your cannabis facility or visit our web page Competitive Technology to learn more. 

If you want to skip the entire research process, then we have good news for you! We have researched for you! AirROS surface and air purifiers are the only purifiers that can sanitize air and surfaces (including long-distance surfaces) organically without using chemicals and as a bonus, replaces your carbon filters for odor control. AirROS uses ROS (Reactive Oxygen Species) to dramatically reduce pathogens, including powdery mildew, and reduce VOC’s which provides odor control. In addition, AirROS will kill at the source of the contamination before it starts spreading. This has delivered proven results in multiple cannabis facilities and grow rooms.

Powdery mildew is common and difficult to control plant disease that can devastate cannabis crops. This blog post outlines the main points of how you can prevent powdery mildew in your facility with some simple steps. These strategies include using dehumidifiers, proper airflow, an air purifier (including surface treatment), and maintaining adequate humidity levels. If you’re interested in learning more about preventing mold, including powdery mildew and other pathogens at your grow operation using AirROS surface and air purifier then Schedule a call today.




  • […] creates and utilizes ROS (Reactive Oxygen Species) to reduce pathogens, bacteria, molds (BOTRYTIS, POWDERY MILDEW), cross-contamination, and odor control. The ROS is organic, which means it doesn’t use […]

  • […] Powdery mildew is a fungus that can grow on surfaces in the cannabis room, such as walls, floors, plants, and other objects. This fungus will multiply when there are high levels of humidity or stagnant air in a cannabis room. To prevent this from happening, cannabis growers should clean all surfaces with hydrogen peroxide and dry them thoroughly before moving any plants into the area. The last thing a cannabis grower wants is for their cannabis crop to get infected with powdery mildew. These spores can cause devastating effects on a plant, and they must take precautions to prevent the spread of the fungus. The fungus can cause damage to their cannabis room by reducing growth or yield. […]


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