When growing Cannabis, dealing with grey mold and bud rot is a reality. Growing Marijuana Perfectly wrote a great article about the best tactics for defeating gray mold. One of those tactics is to use UV-C Light.


“Ultraviolet light kills gray mold or controls its spread so an infestation is less disastrous. Ultraviolet light fixtures include handheld, free-standing units, and units placed in-line in air conditioning and ventilation systems (take a look here).

Just 1-3 minutes of UV-C applied to plants every 2-3 days during bloom phase, followed by at least four hours of lights-off, is the optimum way to use UV-C to kill gray mold in live plants. 

Gray mold treated with UV-C and subjected to four hours of darkness is unable to reproduce and re-infect. But gray mold treated with UV-C and then placed under light is later still able to reproduce and re-infect.

Apply UV-C light to harvested buds, starting at harvest time and all the way through drying and curing. Duration of application can be constant during the drying and curing process, because there’s no photosynthesis to interfere with.

In fact, UV-C degrades chlorophyll (which is why you should use it sparingly around live plants), and the less chlorophyll in buds, the better the buds taste and smell.

I use free-standing CleanLight UV-C units in my drying chamber.”


Thank you for mentioning us, Growing Marijuana Perfectly!

Read the whole article here.