As you inspect your cannabis plants, you may come across some leaves with dark spots and white fuzz.
These are telltale signs of mold, and as a cannabis cultivator, discovering this invader can be frustrating. However, you have to act quickly to deal with your moldy cannabis. Mold spores can grow rapidly and spread across your entire crop in the most extreme circumstances.
The key to dealing with a minor setback rather than a business catastrophe is to have a plan in place and know what to do next if you spot mold on your cannabis plants.
Signs Of Moldy Cannabis Plants
Detecting mold on cannabis plants as soon as possible is important for maintaining an overall healthy crop. Mold
can significantly impact both the quality and safety of the final product. Here are some key signs to watch out for:
- Discolored leaves and buds: One of the most noticeable signs of mold is discoloration. Affected leaves or buds may appear yellow, brown or gray, indicating the presence of mold. Look for spots or patches that seem unusual compared to the rest of the plant.
- Powdery coating: Mold often manifests as a fine, white or gray powdery substance on the leaves, stems or buds. This can be mistaken for dust or trichomes, so it’s important to inspect closely.
- Musty smell: Moldy cannabis has a distinctive musty or earthy odor. If you notice a change in the smell of your plants, especially if they become more pungent or unpleasant, it could be a sign of mold growth.
- Brittle or slimy texture: Mold can cause plant material to become brittle and dry or slimy and wet, depending on the type of mold. This texture change can make buds crumble easily or feel sticky and unpleasant to the touch.
- Visible mold growth: In advanced cases, mold may appear as fuzzy growths, often white, green or black, on the surface of leaves, stems or buds. This is a clear indication that the plant is heavily contaminated and should be removed immediately.
If you notice any of these signs, act quickly to isolate and remove the affected plants to prevent the spread of mold to the rest of your crop. Regular inspection and proper environmental control can help mitigate the risk of mold in cannabis cultivation.
Types Of Mold Found On Cannabis Plants
Cannabis plants are susceptible to various types of mold, each posing unique challenges to cultivators. Understanding these molds and their effects is crucial for maintaining healthy crops. Here are a few types of mold commonly found on cannabis plants.
Powdery Mildew (PM)
Powdery mildew, often referred to as “PM,” is a widespread mold that can be particularly harmful to cannabis plants. It typically appears as a white, dusty substance on the fan leaves, though it can spread to other parts of the plant.
This mildew, technically known as mycelium, hinders plant growth and renders the flowers unsafe for consumption. PM is especially common in warm, humid environments, such as greenhouses, so vigilant inspection and routine defoliation are essential to prevent its spread.
Botrytis (Bud Rot)
Botrytis, also known as “bud rot,” is another dangerous mold that affects cannabis plants, especially during the flowering stage. It starts as fuzzy, gray patches of mold and rapidly deteriorates the buds, turning them brown and unfit for use.
A telltale sign of botrytis is the gradual change in leaf tips from yellow to brown, indicating that the mold is present and spreading.
Fusarium
Fusarium is a less common but highly destructive mold that primarily targets the roots of cannabis plants. This soil-borne mold causes root rot, disrupting the plant’s ability to photosynthesize and absorb nutrients. The earliest sign of fusarium infection is wilted leaves, which can quickly lead to the plant’s decline if not addressed.
How To Avoid Mold Growth
Preventing mold growth can help prevent surprises as you’re inspecting your cannabis plants. As a cultivator,
here are eight tips to help you minimize the risk of mold:
- Control humidity levels. Mold thrives in high-humidity environments. Keep your grow room or greenhouse humidity between 40-60% during the vegetative stage and lower it to 40-50% during flowering. Use dehumidifiers and ensure proper ventilation to maintain these levels.
- Ensure proper airflow. Good airflow helps prevent stagnant air pockets where mold can thrive. Install fans to circulate air evenly throughout your growing space, and use exhaust systems to remove excess moisture and heat.
- Monitor temperatures. Mold tends to develop in warm environments. Keep the temperature between 70-85°F (21-29°C) during the day and slightly cooler at night. Avoid temperature spikes, which can lead to condensation and mold growth.
- Regularly inspect plants. Early detection is key to preventing mold from spreading. Inspect your plants daily for any signs of mold, especially on leaves, buds and soil. Pay special attention to the lower parts of the plant where humidity may be higher.
- Prune and defoliate. Regular pruning and defoliation help improve airflow around the plants and reduce areas where mold can develop. Remove any dead or decaying leaves and avoid overcrowding plants to ensure they have enough space to breathe.
- Water plants correctly. Overwatering can lead to excess moisture in the soil, creating an ideal environment for mold. Water your plants at the base and avoid getting the foliage wet. Ensure proper drainage to prevent water from pooling in the soil.
- Use mold-resistant strains. Some cannabis strains are more resistant to mold than others. If you’re growing in a humid environment or are prone to mold issues, consider choosing strains known for their resistance to mold.
- Maintain cleanliness. Keep your grow space clean and free of debris. Mold spores can cling to tools, clothing and surfaces, so regularly disinfect tools and clean your growing area to minimize contamination.
By following these tips, you can significantly reduce the risk of mold growth in your cannabis cultivation.
What To Do With Moldy Cannabis
Whether or not you can save moldy cannabis plants depends on the extent of the mold growth. If caught early, small patches of mold can sometimes be pruned away, and the plant may be salvageable with improved environmental controls and treatment.
However, if the mold has spread extensively, it’s often best to dispose of the affected plants to prevent further contamination and ensure the safety of your crop.
When plants must be disposed of, it’s important to do so in compliance with cannabis waste disposal guidelines. In California, for instance, cannabis waste must be rendered unrecognizable and unusable before disposal. This typically involves grinding the plant material and mixing it with other non-cannabis waste to ensure it cannot be used or resold.
A cannabis waste disposal company can assist with this process, ensuring that your disposal methods meet legal requirements. Cannabis waste solutions specialize in safely and effectively disposing of cannabis waste, providing peace of mind that your plants are being handled in accordance with state regulations.
When choosing a cannabis waste disposal company, consider several key factors that include:
- If the disposal company is fully licensed and compliant with local and state regulations regarding cannabis waste disposal
- Experience in cannabis waste disposal, including a track record of working with cannabis cultivators and understanding the unique challenges and regulations associated with the industry
- A secure and traceable process, including documentation of waste destruction
- Environmentally friendly practices, such as composting or access to waste-to-energy processes
- Reliable service and support, as well as the ability to accommodate your specific disposal needs, whether it’s a one-time pickup or a regular service
- Transparent pricing so you can understand their fee structure and ensure it aligns with your budget and disposal volume
By working with a licensed disposal service, you can focus on maintaining the health of your remaining crop while ensuring compliance with the law.
