Medically Reviewed by
Jason Crawford

Article Last Updated on December 24, 2022

You know it’s gonna be a good day when your medical marijuana buds are in perfect condition, since you’re able to get your dose and go on with your other activities. But what if one day you open your glass jar and see nothing but moldy buds? Is your cannabis safe to consume, or will placing those nugs in a bong cause you health problems? 

Figuring out what to do with your moldy cannabis plant material will be the topic of this article, so don’t throw them away just yet. And if you’re interested in learning more about moldy weed, you can read some of our previous articles like Can Weed Get Moldy and What Mold Looks Like on Weed. Without further ado, let’s get into the topic of moldy cannabis and what to do with it.

The 411 on Mold Growth in Cannabis Plants

Before we go into the subject of what to do with your moldy weed, we first need to go over what mold is. 

Mold is a fungal species which reproduces through microscopic airborne spores in moist environments. Mold spores can be found in places with sufficient moisture, including moist places in your house, like your pantry and fridge, and even in your weed stash if enough moisture accumulates. In small quantities, mold is harmless for humans because the immune system kicks in and prevents damage, but it can cause health problems in larger quantities which is why cannabis growers should pay special attention to the conditions in their grow rooms.

Mold can develop in several places in your home, including your weed stash. It often develops in humid grow rooms with poor air circulation, and in cannabis storage containers if the bud isn’t properly dried before being stored, and even dispensaries can have a problem with moldy cannabis.

Common mold types include Penicillium, Botrytis cinerea (bud rot), Aspergillus, and Cladosporium, just to name a few. 

Mold Found in Cannabis Plants

There are two types of mold that are often found in cannabis, and those are grey mold and powdery mildew.

Powdery Mildew (White Mold)

Powdery mildew, or white mold, may look similar to trichomes to the inexperienced eye, however, this type of mold and the resinous trichomes have nothing in common. This type of mold thrives in grow rooms with poor air circulation and can spread quickly to other plants in the vicinity.

Botrytis Cinerea (Grey Mold)

Botrytis cinerea, or bud rot, is often caused by excessive moisture trapped inside the colas and develops from the inside out. When growing indoors, bud rot is common in moist and humid grow rooms, and when growing outdoors, grey mold is often caused by heavy rainfall.

What Happens if You Consume Moldy Weed?

Cannabis users consume weed either recreationally or medically to get full advantage of the cannabinoids in weed such as tetrahydrocannabinol (THC) and cannabidiol (CBD), as well as the other compounds. However, consuming moldy cannabis can be very dangerous to your health. Especially because mold spores are very resilient and survive extreme conditions like high heat, which is why they won’t be destroyed when you decarb your weed. But how does smoking moldy weed affect people?

When mold is ingested, it can cause an allergic reaction in people with an allergy to penicillin. In others, it can produce mycotoxins which are potentially carcinogenic, and smoking moldy weed can even result in lung infection in immunocompromised people. For that reason, both recreational and medical marijuana users should pay extra attention when purchasing or growing their weed to prevent these unwanted side effects. 

How to Check for Moldy Weed?

To figure out whether your weed plants are mold-free, you can use the following techniques:

  • Inspecting your stash (mold can look like white fuzz or dark spots, so it’s often easily spotted by the naked eye);
  • Smelling your stash (terpenes give a rich aroma to your weed, but a musty smell can indicate moldy weed);
  • Looking at your stash under a microscope (if your buds have been infested recently, the mold spores may not be visible with the naked eye, so inspecting your stash under a microscope or a magnifying glass is a great method to check for mold presence);
  • Comparing it with online photos (if you don’t know what mold looks like, you can always look for microscopic pictures of moldy weed online and compare those photos with what you’re seeing under the microscope).

A Guide for Keeping Your Weed Mold-Free

When it comes to keeping your cannabis mold-free while growing it, adequate growing conditions are essential. Specifically, maintaining a grow room with adequate lighting, proper temperatures, and relative humidity levels, as well as regularly inspecting your cannabis plants for mold and other infections. Depending on the stage of growth, pot plants should be kept in grow rooms with a temperature between 68 and 77 degrees Fahrenheit, with relative humidity levels ranging from 40% to 70%. 

After your plant is fully grown and harvested, proper drying and curing of the cannabis plant are essential for preventing mold and bud rot. Adequately drying and curing your weed will not only prevent the above-mentioned conditions, but will ensure that you preserve the rich terpene and cannabinoid profile of your cannabis buds at the same time.

The final step for keeping your buds mold-free is proper cannabis storage. Ideally, your buds should be kept in a cold place, away from direct sunlight, in a dark-colored airtight container. The humidity levels in the storage container should range between 59% and 63%, and the storage temperature should be below 77 degrees Fahrenheit.

What to Do With Moldy Weed?

We’ve gone over the types of mold that are commonly found in cannabis plants, how they affect the health of marijuana users after ingestion, as well as how to check your weed plants for mold, but we have yet to answer the question “What to do with moldy weed.”

Consuming properly grown, dried, cured, and stored weed, can help you with a lot of medical conditions, but, consuming moldy weed can have negative effects on your health, especially if you’re an immunocompromised medical marijuana user. As we’ve previously mentioned, moldy weed can’t be destroyed by heat or removed from your buds in any other way, so the only option you have is to throw it out. 

The bottom line is that once contaminated, moldy weed isn’t safe to use because it can either result in the user having health problems if they’ve consumed moldy buds, or the mold can spread to your other plants if it has started developing during the cannabis growth stages.

For that reason, cannabis cultivation should be done under optimal growing conditions and stored properly so users can get the full benefits when consuming this plant either as a medicine or recreationally.

Final Thoughts

If you decide to cultivate cannabis, you need to do it right. Since moldy marijuana ingestion can result in a lot of side effects and harm the consumers’ health, marijuana growers need to be extra careful in order to avoid that.

It would be a good idea to inspect your cannabis during each growth stage to make sure that it’s mold-free. It’s also important to properly dry, cure, and store your cannabis buds to maintain the quality and aroma of your weed. Growing and storing your cannabis in optimal conditions will not only make your weed-growing experience more pleasant since there will be less risk of mold formation, and you’ll also get higher-quality weed as a result.             

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.