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What Is Cannabis Bud Rot? The Top Answers & Why You Need to Know

With a name like bud rot, you know it can’t be good. Cannabis bud rot is something no grower ever wants to see in the later phases of plant maturity. Salvaging bud rot is nearly impossible but knowing the common bud rot causes can help you prevent it. So, to avoid bud rot altogether, keep reading for our ultimate guide to cannabis bud rot and the top facts you need to know. 


What is Bud Rot? 


Put simply, cannabis bud rot is a fungus or mold that can grow on cannabis plants. More technically it’s known as botrytis cinerea, or gray mold. The pathogen initially develops from the center of the buds, and stem and normally appears in the late stages of bloom. With just the right (or wrong!) conditions the mold can spread from the inside out taking over the entire nug. 

As you may know, molds are highly concerning when growing weed as it can make the flower unsafe to consume. Even more, fungus and molds like cannabis bud rot can grow rapidly. That means identifying bud rot and knowing the first signs of bud rot is key. Next, let’s cover the top ways to do so. 


How To Identify Cannabis Bud Rot 


Now, knowing that cannabis bud rot begins in the heart of buds it can easily go unseen. That means, towards the end of flowering you may want to open up buds and peer inside to see if any molds are visible. For cannabis bud rot you’ll notice an odd discoloration that looks somewhat burnt, dark gray or brown in color. Usually, bud rot affects denser buds more than others but that doesn’t mean it holds back from all parts of the plant. 

Unfortunately, the top main colas are often the most dense. Meaning cannabis bud rot can be detrimental to the best parts of your plant. In addition to discoloration, you may also notice the outer parts of the plant dying as cannabis bud rot symptoms. Like, buds, pistils or leaves showing signs of shriveling. This initial sign of bud rot might be an indicator to take a closer look. Cannabis bud rot may also look white and fluffy on the outside, which is the actual spores of the fungus. 

To help prevent the problem from occurring, it also helps to know what causes bud rot in cannabis. Rest assured, we’ll cover that next. 


What Causes Cannabis Bud Rot? 

Cannabis Flower Bud Rot


First off, it’s important to understand fungus like molds develop in humid, damp and warm conditions. Which means the environment in which your plants grow is one of the main bud rot causes. Specific factors that contribute to the development and growth of cannabis bud rot include - 

  • High levels of humidity
  • Mild or cold temperatures 
  • Wet or rainy conditions
  • Poor indoor ventilation
  • Dense foliage and buds

In addition, plants with weak immune systems can be more susceptible to cannabis bud rot. Furthermore, certain strains or genetics can be more prone to mold development as well. If you grow outdoors in a climate that has high humidity, frequent rain or milder temperatures - you may want to choose a strain from the start that’s resistant to molds. Keep in mind, sativa strains tend to be lighter and airier and overall more mold resistant. On the flip side, indica strains originated from dry regions in Asia so when grown in areas with high humidity they can be more susceptible to molds.


Can You Treat Bud Rot? 


If you’re in a position where bud rot is present on your plants you may ask, is salvaging bud rot possible? Unfortunately, there is no way to treat bud rot. Once it appears on your plant, you should cut the infected buds, nugs, or entire stems off of the plant. In this case, there may be a way you can prevent the spread. However, if not caught in time - you may have to discard the whole plant. Of course, no grower wants to throw away all of their hard work, time and energy. So, let’s brush up on the basic ways to prevent bud rot when growing and bud rot after harvest.


Cannabis Bud Rot Prevention Tips - Growing 


While preventing bud rot outdoors might be more difficult, here are a few of the top ways for prevention - 

  1. Improve airflow or air circulation with additional fans, or exhaust systems.
  2. Control humidity levels with hygrometers and dehumidifiers indoors.
  3. Increase spacing between plants.
  4. Inspect plants for signs of bud rot daily. 
  5. Avoid the pooling of water or areas of standing water. 
  6. Defoliate plants to remove excess leaves to additionally boost plant airflow.  
  7. Maintain proper levels of nutrients, as plants that are improperly fed will have weaker immune systems. 
  8. If growing outdoors, consider using a greenhouse to avoid plants being rained one. Or, lightly shake off plants after a heavy rain.

Cannabis Bud Rot Prevention Tips - Drying


Of course, you’re not in the clear of cannabis bud rot after harvesting. Cannabis bud rot can also occur during the drying or curing phase if optimal conditions are not kept. To decrease your chances for developing bud rot after harvest, be aware of the following tips - 

  1. Allow plants moisture levels to decrease before pulling. This could mean harvesting your plants during a dry spell. 
  2. Before drying, consider wet trimming excess fan and sugar leaves to reduce moisture. 
  3. Just like growing, leave space between stalks or plants when drying. Take your environment just as seriously in your drying room, and use dehumidifiers and fans to maintain optimal conditions. 
  4. The best conditions to avoid cannabis bud rot when drying and curing are temperatures of 60-70°F and humidity between 50-65%.

The Bottom Line


All in all, cannabis bud rot is something you’ll want to avoid when growing or drying buds. Luckily now, you have the proper information to do so. Be sure you’re maintaining optimal conditions with the tips you’ve learned today to avoid common bud rot causes. But, now that you’re properly trained on identifying bud rot, also be sure to keep a good eye out for it. For more growing tips and tricks stay tuned to 420 Seeds or browse our selection of seeds for top-quality genetics.

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