top of page

Search Blog Articles

  • Writer's pictureARCannabisClinic

What to Do? How to Get Rid of Mold on Marijuana Plants

Mold is an adversary that cannabis growers dread. Whether it manifests as the white powdery mildew, the disconcerting gray mold, or any other type, it can jeopardize the entire crop. Recognizing the signs of mold early on and understanding the best way to deal with it can make a significant difference in the health of marijuana plants. This article aims to equip growers with the knowledge to combat mold and produce healthy, top-quality cannabis.

White mold on a cannabis plant

Table of Contents:

Understanding Mold on Marijuana Plants:

Mold on marijuana plants is a concern that's long been shared by cannabis growers. It's an unwelcome guest, one that can ruin an entire crop if not handled promptly. Let's delve into this, understanding the intricacies of mold, its impact on marijuana plants, and methods to prevent its growth.

Mold spores are everywhere, from our homes to our gardens. For the most part, they're harmless, but given the right conditions, they can quickly colonize and wreak havoc. Specifically, high humidity levels combined with poor air circulation are the leading causes of mold formation on marijuana plants. When these conditions are met, the mold spores find an ideal breeding ground on the lush green surfaces of the cannabis plant.

Now, there are different types of mold one might encounter. Gray mold, often referred to as bud rot, is perhaps the most dreaded among cannabis growers. It often targets the cannabis buds, making them unusable. On the other hand, white powdery mildew covers the plant in a fine, white, powdery substance that's easy to identify.

Detecting mold in its early stages is crucial. To the naked eye, initial mold growth can be mistaken for little white spots or perhaps some dark patches on the leaves. But as it spreads, it can cover an entire plant, and if unchecked, can affect the entire crop, especially in indoor grow rooms with stagnant air. Mold doesn't discriminate, and even if you've put in your best efforts, an infected plant can be a reality for many growers.

Treatment, of course, varies. Natural remedies such as neem oil can prevent mold growth. Some growers opt for diluted solutions of hydrogen peroxide, which can exterminate mold spores without harming the marijuana plant. The importance of ensuring a well-ventilated growing area cannot be stressed enough. Good airflow ensures that mold spores don't settle on the plants, and even if they do, they don't get the stagnant environment they need to proliferate.

White mold on a cannabis plant
White mold on a cannabis plant

Additionally, one cannot overlook the potential harm of moldy weed on consumers. Beyond just a drop in quality, consuming moldy cannabis can lead to allergic reactions and, in more severe cases, even lung infections. This makes understanding and preventing mold not just a matter of preserving the crop but also a critical health concern.

For those who are seeking more insight on the medicinal properties of marijuana and how to avoid complications like mold, the marijuana cultivation consult on ARCannabisClinic's website offers comprehensive information. Furthermore, consumers who are curious about the benefits and potential risks associated with medical marijuana might find ARCannabisClinic's marijuana therapy an invaluable resource.

For more updates and insights into the cannabis world, consider following @ARCannabisclin1 on Twitter.

Key Takeaway: The growth of mold on marijuana plants is not just a potential loss in crop yield but poses a genuine health risk to consumers. Prevention through proper care, good airflow, and regular inspection is the most effective approach. And when in doubt, seeking professional advice or therapy can ensure both the health of the crop and the safety of the consumers.

Recognizing the Signs of Mold:

Mold on marijuana plants, whether growing at home or sourced from a dispensary, is not only detrimental to the quality of the plant but also a potential health risk for the consumer. Recognizing the early signs of mold can save both your crop and your health. As the saying goes, prevention is better than cure, but recognizing a problem early on is the next best thing.

For growers, the dense and compact nature of marijuana buds can often obscure mold. However, there are certain unmistakable signs to look out for:

  1. Discoloration: Mold typically presents itself as white, gray, or even black spots on the buds and leaves of the marijuana plant.

  2. Musty Odor: A healthy marijuana plant should have a fresh, earthy aroma. The presence of mold introduces a musty, damp, and off-putting smell that's easy to recognize once encountered.

  3. Powdery Residue: White powdery mildew is a common type of mold that appears as a fine, white, powdery substance on the leaves and buds.

  4. Bud Rot: A particularly insidious form of mold, bud rot turns the insides of the buds to a mushy, brown mess, making them completely unusable.

  5. Web-like Structure: In some cases, especially with higher humidity levels, the mold might produce a web-like structure around the buds.

For consumers purchasing marijuana from dispensaries, it's essential to inspect the product visually and olfactorily. Apart from the visible signs of mold, if the product smells off, it's best to avoid consumption.

Why is mold on marijuana such a concern? Ingesting or inhaling mold spores can lead to allergic reactions, respiratory issues, and other health complications. Especially for medical marijuana patients, who might already be grappling with conditions like PTSD or severe arthritis, consuming moldy weed can further exacerbate their health problems.

For those diving into the world of marijuana cultivation, understanding the plant's optimal growing conditions and potential threats is paramount. External resources, such as Leafly's guide to recognizing mold, can be invaluable in gaining this knowledge.

white mold on the cannabis marijuana plant

It's crucial for growers and consumers alike to be well-informed. After all, marijuana is a product that can offer immense therapeutic benefits, but only if consumed safely and responsibly. For more about the health benefits of marijuana, do visit ARCannabisClinic's page on how marijuana helps with epilepsy and seizures.

For those interested in understanding more about mold and marijuana, @ARCannabisclin1 on Twitter frequently shares invaluable insights and tips.

Key Takeaway: Recognizing the signs of mold on marijuana is a combination of visual inspection and olfactory discernment. Ensuring the health and safety of both the crop and the consumer requires vigilance and timely intervention. Remember, knowledge and prompt action can save both the quality of your marijuana and potentially your health.

Preventative Measures for Mold Growth:

Mold poses a significant threat to the marijuana cultivation industry. Not only does it compromise the quality of the plant, but it also has potential health implications for consumers. Therefore, it's imperative for growers, whether seasoned or beginners, to employ proactive strategies to ensure that their crops remain mold-free.

  1. Control Humidity: Mold thrives in high humidity conditions. Maintaining a humidity level between 40% to 50% during the flowering stage can reduce mold risks. Tools such as dehumidifiers or air conditioning can help in maintaining these levels.

  2. Adequate Ventilation: Ensure that your growing space has proper air circulation. Oscillating fans can prevent mold spores from settling, but be sure not to point fans directly at plants to avoid stress.

  3. Regular Inspection: Consistent checks on your plants, especially during the flowering stage, can help detect early signs of mold. Utilize a magnifying glass to inspect areas difficult to see.

  4. Cleanliness: Keeping your cultivation area clean can significantly decrease mold risks. Remove dead leaves or plants, clean tools regularly, and consider wearing gloves when handling plants.

  5. Natural Fungicides: Before mold appears, one can use natural fungicides, such as neem oil or apple cider vinegar, to prevent mold growth. However, always test on a small area before widespread application.

  6. Optimal Plant Density: Overcrowding can restrict airflow and create a conducive environment for mold. Ensure plants have ample space to grow without touching each other.

  7. Control Watering: Overwatering can lead to excess moisture, making it easier for mold to thrive. It's crucial to water plants when necessary and avoid letting them sit in standing water.

For those considering diving into marijuana cultivation, being informed is crucial. While the ARCannabisClinic's cultivation consult provides detailed guidance on the topic, it's also beneficial to explore resources from leading cultivation experts. For instance, this comprehensive guide on preventing mold offers a wealth of information on the subject.

Taking preventative measures for mold growth not only ensures a higher yield but also a safer product for consumption. Especially when catering to a market that seeks therapeutic benefits from marijuana, such as those with severe arthritis or PTSD, the quality and safety of the product cannot be compromised.

In the world of marijuana cultivation, knowledge is the grower's best friend. Keep abreast with the latest insights and updates on mold prevention through @ARCannabisclin1 on Twitter.

Key Takeaway: Mold prevention in marijuana cultivation hinges on meticulous care, regular inspections, and controlling environmental factors. Growers must remain vigilant and proactive, understanding that the health of their consumers and the quality of their product go hand in hand.

Effective Methods to Treat Moldy Weed:

In the world of cannabis cultivation, encountering moldy weed is an unfortunate yet not uncommon setback. Mold can jeopardize both the quality of marijuana and the health of those who consume it. Thus, effectively addressing mold becomes paramount.

  1. Identification is Key: Before treating mold, growers must first confirm its presence. This often involves a visual inspection under good light, perhaps aided by a magnifying glass. If you spot a powdery or furry texture different from the natural trichomes or if there's an odd odor, chances are mold is present.

  2. Isolate Affected Plants: Once you identify mold on a plant, separate it immediately. This prevents cross-contamination, shielding other plants from potential infestation.

  3. Use a Hydrogen Peroxide Solution: A diluted mixture of hydrogen peroxide and water can address mold on the surface. Gently spray the solution on affected areas, ensuring it doesn't overly saturate the buds.

  4. Consider the Bud Washing Technique: Some growers swear by a method known as 'bud washing.' This involves gently swishing the harvested buds in a lukewarm water solution with hydrogen peroxide. It's essential to rinse them in clean water afterward and dry them thoroughly.

  5. Desperate Times, Desperate Measures - Dispose: In cases where the infestation is severe, the best course might be to discard the affected portions or even the entire plant. Consuming moldy weed can lead to health complications, especially for patients using marijuana for therapeutic benefits, like those battling anxiety.

  6. UV-C Light Treatment: There's research indicating that UV-C light can kill mold spores on the cannabis plant. It's a non-chemical method, but requires caution to ensure you don't damage the plant or reduce its potency.

  7. Prevent Future Outbreaks: While treating mold is essential, preventing its occurrence is even more vital. Review your cultivation practices and consider measures like dehumidification, proper ventilation, and regular inspection.

If you're considering using cannabis for its therapeutic benefits, ensuring that your supply is mold-free is crucial. An informed consumer is a safe consumer, so always educate yourself on the qualifying conditions and choose products from reputable sources. For further insights on mold and cannabis, this detailed guide on mold and weed is an excellent external resource.

Consumers need to be aware and proactive. Stay updated with the latest insights on mold and cannabis through @ARCannabisclin1 on Twitter.

Key Takeaway: Addressing mold in cannabis is not merely about salvaging a crop, but ensuring the safety and health of consumers. Prevention, timely detection, and effective treatment are critical components in the battle against mold. Always prioritize health and quality over quantity.

Handling Mold During the Drying and Curing Process

One of the critical phases in cannabis cultivation is the drying and curing process. While it ensures the optimal preservation of cannabinoids and terpenes, the moisture involved can be an open invitation to mold growth. Therefore, it's imperative to take necessary precautions during this stage to keep your cannabis mold-free.

1. Adequate Ventilation: Ensure proper airflow in the drying area. A well-ventilated space reduces the chances of mold growth by ensuring that the moisture released from the buds is carried away effectively.

2. Regularly Monitor Humidity Levels: It's essential to maintain a relative humidity of 45-55% during the drying process. Investing in a reliable hygrometer can give you precise readings. If the humidity rises, consider using a dehumidifier.

3. Optimal Temperature: Keep the drying room's temperature between 60°F to 70°F. Mold thrives in warmer conditions, so maintaining this cooler temperature range can be a deterrent.

4. Spacing and Hanging: When hanging cannabis to dry, ensure there's enough space between branches. This spacing promotes airflow and minimizes the risk of mold growth on closely packed buds.

5. Inspect Regularly: Always be vigilant. Regular inspections can help detect mold early on. If you find mold, isolate the affected buds immediately to prevent further spread.

6. Shorten the Drying Time: While a slow drying process is ideal for maintaining quality, in conditions that favor mold growth, consider shortening the drying time. But be wary of drying too quickly, as it may degrade the product's quality.

7. Jar Curing and Storage: Once your cannabis is dry, store it in airtight containers. Open these jars daily for the first couple of weeks to allow fresh air in, which also helps in reducing mold risk.

Cannabis dispensary marijuana product in glass jar

8. Be Mindful of Storage Areas: Choose a cool, dark place for curing. Just as patients suffering from PTSD find solace in certain environments, the same principle applies to cannabis; it has optimal environments where it thrives without the threat of mold.

If you're keen to delve deeper into the subject of molds and their prevention during the curing process, here's an insightful article that sheds light on best practices and techniques.

Handling mold is crucial not just for the quality of the product, but more importantly, for the health and safety of its consumers. Cultivators need to ensure their products are mold-free, especially if it's intended for medicinal use.

Staying updated on best practices in cannabis drying and curing can be a game-changer. Here's a thought worth sharing: @ARCannabisclin1 on Twitter.

Key Takeaway: The drying and curing stages are critical in cannabis cultivation. By ensuring proper procedures and environments, cultivators can significantly reduce the risk of mold, ensuring a safe and high-quality product for consumers.


  • What causes mold to form on marijuana plants? Mold formation is primarily due to high humidity levels, poor air circulation, and the presence of mold spores in the growing environment.

  • How can I recognize white powdery mildew on my cannabis? White powdery mildew appears as white spots or a fine, flour-like substance on the surface of marijuana plants.

  • Is gray mold the same as bud rot? Yes, gray mold is often referred to as bud rot when it affects the cannabis buds.

  • Can mold spores affect my entire crop? Yes, airborne spores can spread easily and infect an entire crop, especially in indoor grow rooms with stagnant air.

  • What are the early stages of mold growth on weed plants? In its early stages, mold might not be easily visible to the naked eye but can appear as tiny white spots or dark patches on the leaves or buds.

  • How can I prevent mold growth in the first place? Adopting preventative measures such as controlling relative humidity, ensuring good airflow, and regularly inspecting plants can help prevent mold growth.

  • Are moldy weed plants safe to consume? Consuming moldy weed can lead to allergic reactions and potential lung infections. It's advised to avoid using moldy cannabis.

  • How can neem oil help in preventing mold? Neem oil is a natural remedy that can prevent mold growth by creating an inhospitable environment for mold spores on cannabis plants.

  • Does hydrogen peroxide kill mold on marijuana plants? Yes, a diluted solution of hydrogen peroxide can be effective in killing mold spores without harming the plant.

  • How does potassium bicarbonate help in mold prevention? Potassium bicarbonate disrupts the pH level on the leaf surface, making it difficult for mold and powdery mildew spores to thrive.

  • Can I use UV light or direct sunlight to treat moldy cannabis plants? UV light, especially UVC light, can be effective in killing mold spores. However, prolonged exposure to direct sunlight can damage the plant.

  • Why is good airflow important in preventing mold? Good airflow ensures that there's no stagnant air around the marijuana plants, reducing the chances of mold spores settling and proliferating.

  • What happens if mold forms during the drying process of cannabis? Mold formed during the drying process can ruin the quality of the marijuana. It's crucial to ensure good air circulation and humidity control during this stage.

  • How can I detect mold that's not visible to the naked eye? Using a magnifying glass or a black light can help in identifying moldy areas that aren't easily visible.

  • Is it a good idea to segregate moldy cannabis plants from healthy ones? Absolutely. Segregating moldy plants can prevent the spread of airborne spores to healthy plants.

  • Can poor air circulation alone lead to mold growth? While poor air circulation is a significant factor, high humidity levels and the presence of mold spores are also necessary for mold growth.

  • How often should I inspect my indoor grow rooms to prevent mold growth? Regular inspection, at least once a week, is recommended to detect early signs of mold and take necessary actions.

  • What should I do if I find moldy bud during the vegetative stage? It's best to remove the infected parts immediately to prevent the spread of the fungus and monitor the plant closely.

  • Can mold spores survive in mason jars during the curing process? Yes, if there's excess moisture in the jar or if the marijuana was moldy before being placed in the jar, mold spores can proliferate.

  • Is there a commercial product that can effectively treat moldy weed plants? Several commercial products can treat mold. However, natural remedies like neem oil and hydrogen peroxide are also effective and are often preferred due to their organic nature.


Mold on marijuana plants is a challenge, but with the right knowledge and timely action, it can be managed. Early detection, understanding the type of mold, and applying the best methods for treatment are key. Cannabis growers who prioritize these steps can ensure a healthy crop, free from the threats of mold and fungal disease.

For those seeking professional guidance on medical marijuana, ARCannabisClinic is a reputable company offering a national network of marijuana doctors. They assist patients in obtaining legal access to medical marijuana in their state. ARCannabisClinic also offers an industry-leading MMJ Therapy Visit, which provides patients with a medical marijuana treatment plan. This plan includes strains, ratios, and dosing instructions, tailored to each individual's needs. Additionally, the clinic is a pioneer in full diagnosis evaluations, which includes PTSD, anxiety, and general medical evaluations. This allows patients to bypass the often cumbersome process of collecting outside medical records. In the world of medical marijuana, trusting a reputable company like ARCannabisClinic ensures you're receiving the best advice and care available.

Recent Posts

See All


doctor talking to a patient about medical marijuana as an option for treatment


Experience the convenience of ARCannabisClinic's online doctor visits, offering professional, compassionate, and comprehensive marijuana-based medical advice, all at your fingertips.

medical marijuana patient happy and smiling talking to a marijuana doctor
bottom of page