If you can’t fix the environment, I highly recommend cutting your losses at this point. If you know that it’s still going to be cool, humid or wet for your plants, it’s recommended you harvest immediately to prevent further buds from becoming infected. Buds harvested early are better than moldy buds!
Luckily, healthy cannabis plants will not develop bud rot unless exposed to stagnant air and wet conditions for an extended period of time. Your plants are more susceptible to bud rot, fungus, or mold when the temperature is hot or cold. Aim for a temperature of 75°F (24°C) in the late flowering stage if possible.
If your plant has been affected by bud rot, it means they need less dampness and air that’s more dry. If you can improve the environment, you can allow the plant to continue ripening after you’ve removed the infected buds. However, if you don’t fix the environment it will usually come right back, sometimes even attacking other buds overnight.
Once bud rot has taken hold over parts of a cannabis plant, the buds can sometimes look almost the same on the outside, at first, but they usually start looking like they’re dying in patches. Often the area will dry out and easily pull apart. The inside of buds can turn brown, gray or even purple.
A good outdoor strain for those worrying about bud rot might be Auto Frisian Dew, an award-winning, mold-resistant strain made for outdoors. This strain goes from seed to harvest in about 12 weeks. Just plant seeds after the last frost in the Spring, then harvest 3 months later.
Avoid plant wounds. Avoid injuring your plants, especially in the flowering stage. Don’t leave open wounds to seep out water and nutrients – cover any open injuries with tape or some other “cast” until injury closes up. Avoid pests and keep plants healthy. A healthy plant is much less susceptible to all kinds of infections.
These are the most important points to remember…
As soon as even one part of a single bud starts showing signs of grey mold, the rot can spread to the rest of the cola and then to other buds on the plant. If triggering conditions (lack of airflow, wetness) have not improved, a single point of infection can quickly ruin the harvest of an entire plant.
Keep humidity under 50% RH (Most important!) – This is the most important thing you can do to prevent bud rot from growing. It’s rare to see Botrytis in dry conditions. Learn how to control the humidity. If you don’t fix this, the bud rot may keep spreading even after you’ve removed all the affected buds.
Bud rot is a mold that develops in the thickest parts of cannabis buds. Read for more information on how to prevent and solve bud rot before spreading!
Because outdoor growers can’t control rain levels or morning dew, outdoor plants have the potential to be saturated on a daily or nightly basis. Outdoor grows, particularly in coastal regions, can be plagued by bud rot because controlling humidity levels is a major challenge.
In the beginning, bud rot attacks a plant’s stem, which will appear mushy and gray. As the infection progresses, signs of bud rot are characterized by wilted, yellow and burnt leaves. It’s tricky to spot bud rot ahead of time because the fungus first takes hold inside the plant and works its way to the outside.
Environmental control is the primary method used to avoid bud rot. Dinsmore and Watson recommend these four prevention steps:
Sometimes plants with bud rot will develop a gray webbing or dusty, white spores. Spores are problematic because they easily travel by wind, water and pollinators, which includes you and any grow room workers. To reduce the spread of spores, change into another set of clothes between rooms or wear a dedicated protective suit in each grow room.
Like any plant disease, bud rot can be a formidable opponent in the garden standing between you and a successful grow.
To prevent the fungus from spreading, remove all infected plants. This may help save some of the other plants. Although at this point, many gardeners will harvest immediately.
After bud rot has set in, there’s not much you can do to reverse the spread of the fungus. If you notice a section of your garden has bud rot, there’s a strong possibility that the rest of your garden is infected too.
“Bud rot doesn’t happen overnight and is most common in larger buds and dense plants because they trap and accumulate moisture,” said Melaney Watson, factory representative of Quest. “Additionally, multiple plants that are close together are at a higher risk of infection.”
Bud rot is a gray mold that occurs in environments with poor air circulation and high moisture, conditions that encourage fungi to grow and flourish.
Successful growers know the signs of bud rot and, as importantly, how to eliminate what causes it. The keys: humidity control and air circulation.