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Coping With Mildew & Mold On Outdoor Marijuana

Updated: Nov 1, 2022

It is that time of year again when many outdoor farmers are scrambling to save their crop before it is taken over by powdery mildew/ PM or bud rot/mold. We put all of this effort in all year and wake up one morning to realizing that everything is at risk! This can be devastating and requires immediate action.

What to do?

The real solutions lie in prevention and harvesting before its too late. Preventing mold and mildew is as simple as choosing the strains that are the most resistant, maintaining our plants to have proper air flow, and spraying with any one of a variety of products that help prevent the spores from ever landing and developing to begin with. Mammoth CannControl is one of our favorites to use in early flowering only. It has a 30 day residual, is organic and safe, and most of all effective for preventing most issues like mold, mildew, spider mites, fungus gnats, white flies, and more. Einstein Oil is another.

Can We Wash It Off?

There are endless debates about washing and treating plants with mildew and/or mold. This author takes a very basic approach and exercises some basic discipline to assure anything we harvest is good and clean medicine. The debate is ridiculous in my eyes. Would you eat moldy fruit or vegetables? How about if they had mildew? Or would you simply throw those effected away and focus on the good fruits? Cutting the mold off of cheese and eating the rest is exactly how we cope with mold on something we ingest. The same is true with cannabis. We cut out the nasty and focus on the good. Washing mold and mildew off of a product to sell for someone else to consume is quite simply unethical and driven by greed. Don't be that person.

Processing and Drying

Once we have harvested our cannabis there is still some work to do and some care to be taken. Again there are many different ways to dry cannabis and endless debates about how everyone's way is the best. Drying cannabis is about efficiently removing the moisture from the flowers in a slow and consistent manner. The environment should be between 65 and 75 degrees Fahrenheit and between 45% and 55% humidity. There are many different ways to hang or rack our harvests up for drying. Hanging branches is the most popular. Nugging our branches to dry in trays requires a lot less room. Whether we are dry trimming or wet trimming plays a role. And so on.

Dry Trimming vs Wet Trimming

Wet trimming is when we harvest flowers from the plant and trim or shape the buds immediately before they begin to soften from being cut off the plant. The advantage to this is that all of your work is done basically and we just need to dry our flowers before we jar them up for curing.

Dry trimming is when we hang our flowers to dry usually still on the branch after we have removed all the sucker leaves. This allows our buds contents to stabilize before we handle them or "bruise the fruit" while it is still fresh. Dry trimmed cannabis usually has a better flavor, smell, and potency. This is a direct result of the stabilization mentioned above. Of course this is still contingent upon proper handling and care of the product. If you picture the flowers as a fruit and take care not to bruise that fruit, you will have a better quality.

It really is a personal preference at the end of the day. Great cannabis can be grown and processed in many different ways and developing our own style is part of the fun and what makes us individuals. Don't worry about how everyone else is doing it and do what makes the most sense for you. Dry trimming does allow us to hang a lot more plants up in a short time. So if you are scrambling like many are this time of year....just get those plants out of the ground before they are lost to mold and mildew. The rest can be sorted out later. Use fans. Get some dehumidifiers in play. Use common sense. Just don't freak out. That never helps.


Once we have trimmed our cannabis and it is dry, we began the curing stage. Curing cannabis is accomplished by placing it in jars and "burping" these jars daily for a few weeks while our flowers transform into the peak of ripeness much like a piece of fruit

picked at the perfect time and handled with care. Make sure your cannabis is dry before you place it in jars. Using Boveda packs in our jars is an excellent way to make sure all of our cannabis is at the perfect level of moisture content. Especially if we let it get a little too dry. For curing, you'll be storing finished buds in containers—typically airtight glass jars—to stop the loss of moisture, and to preserve flavors and aromas. Curing usually takes two weeks to a month, and humidity inside curing containers needs to be between 55-65%.


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