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Preventing Mold While Growing Cannabis


New cannabis growers, and even seasoned growers, can face mold issues. They are preventable. In this article, we’ll explain the three main types of cannabis mold and how to prevent them. It’s important to help those that are new to growing, where it’s legal to do so, to have the most successful crops and healthiest plants possible.

One thing that is important to mention is that mold can occur at any point of the growing stages of the cannabis plant, so it is something you always have to look for.

Bud Rot

Bud Rot occurs most often from lack of air circulation. There has to be moving air in your grow space at all times. When temperatures in your grow are too low, mold has a tendency of forming. Temperatures of 68-degrees or higher are recommended. At the same time, you need to keep the humidity in the room low.

If you notice dark areas in your buds, it is likely bud rot. Bud rot looks different the further it progresses. So, when it’s new, it’s a white, fluffy mold. Dark purple or dark gray/brown spots are noticed as it progresses. Advanced bud rot leaves a speckled dust on your buds that can be blown away, but this doesn’t remove the mold so you still have to trim off the entire bud.

Curing bud rot involves taking the entire bud off of the stem. You’ll also have to remove any buds in close proximity to the rotted buds.

White Fuzzy Mold

White, fuzzy mold is regular mold. You’re most likely to find it on the leaves of the plant. It looks similar to insect webs. This mold can spread with air circulation. Prevention is rather simple, make sure the climate of your grow is appropriate. This means that your humidity level should be 20% at the absolute most but should hover around the 15-percent mark. You should also keep the grow’s temperature around 75 degrees.

This is the most common form of mold. Unfortunately, when you spot mold, it means that you’ll need to harvest your cannabis plant and those in the same grow space as quickly as possible – even if it isn’t quite done growing yet.

Powdery Mildew-Like Mold

If you’re able to catch this type of mold quickly, you can save your cannabis plant and the rest of your crop. It’ll look like flour’s been dusted over the leaves of your cannabis plant. The moment you notice this, you must take action. It spreads like wildfire when left to breed.

This mold eats the plant in order to produce more white powdery mildew. Keep your humidity levels low. Purchase a dehumidifier if you live in a naturally humid environment. Keep your airflow low until you’ve completely rectified the mildewy mold situation. Good ventilation and airflow help prevent mold.

Whenever possible, try to make sure the leaves of your cannabis plant/s aren’t touching much. The more the leaves overlap, the more moisture develops between them, which increases your risk for mildew-like mold.

What to do with Moldy Cannabis

Throw it away. You cannot smoke moldy cannabis. Not only could you end up becoming very ill, you could give yourself a long-term medical condition. Don’t confuse mold for trichomes and crystals though – when your buds are fuzzy from those it’s a good thing!

Closing Thoughts

If you don’t notice mold growing on your cannabis plants until you’ve tried some of your harvest, don’t panic. Just toss the rest of the harvest and start over. Yes, it’s a big loss but you can’t consume moldy cannabis, just like state-licensed facilities can’t sell moldy cannabis. It makes people sick. The key to mold prevention is to keep your grow’s climate tightly monitored.

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