What exactly is bud rot?Bud rot is another term for gray mold, a necrotrophic fungus that’s also known by the scientific name Botrytis cinerea. Bud rot loves cool temperatures and humidity, and it hits more than just cannabis plants—it’s been known to attack wine grapes and strawberries, too.
While plants can’t get bud rot unless they come in contact with the fungus spores, the spores get around. They travel in the air, on clothing, even through water. And once they germinate within your grow, the fungus can quickly move through an entire crop.
How to avoid bud rot on cannabis
While treatments exist that can smother or kill the fungus, applying chemicals to your plants can be risky. For instance, there have been cannabis recalls due to one particular fungicide treatment that, when burned, turns into what Jones described as a “hydrogen cyanide type gas.” Chemical use also can be an issue if you grow organic or medical-grade cannabis.
For those reasons, and for cost and efficiency’s sake, most large-scale growers will simply destroy plants affected by bud rot.
That’s why most experts recommend focusing on bud rot prevention. To that end, four factors affect your susceptibility to bud rot.
The ideal temperature recommended for your grow varies depending on several factors, but keep in mind that bud rot prefers cooler temperatures. Most experts recommend temperatures above 68°F to keep bud rot at bay. In a greenhouse, try to avoid cold nights by using a heater.
2) Presence of spores
If you grow indoors, it’s much easier to avoid Botrytis cinerea spores, but you still should be careful about what you let come indoors. Change clothes before you enter your grow room, and never let pets inside.
3) Food source
Remember that bud rot likes the parts of your plants that have the most moisture, so you’ll need to keep an eye on your denser colas. Of course, if you see infection remove it immediately and don’t let the infected parts of your plants touch those that haven’t been affected.
For indoor growers, limiting humidity is one of the easiest ways to avoid problems with bud rot. (More on this critical topic below.)