Growing cannabis comes with so many things to worry about such as lighting, nutrients, increasing yields,  and so much more. Many growers don’t even think about mold growing on their cannabis plants. 

However, mold can cause many serious health risks. If you notice your cannabis may have mold on it, you should never consume it. 

While consuming cannabis that has mold on it most likely wont cause serious harm to someone with a healthy immune system, it can cause severe harm to those with compromised immune systems. Individuals who consume cannabis with mold may experience coughing, nausea, vomiting, headaches, or even more serious conditions such as aspergilloma, which is basically a clump of mold growing inside the body. 

Cannabis can start to develop mold in the growing process, and after it was harvested if it was not properly dried/ stored. 

No need to worry though, keep reading to learn how to identify mold on your cannabis, and how to reduce the chance of mold appearing.

Weed, like any plant or herb, can grow mold. If you see white stuff on your weed, it’s mold. That means the weed itself has developed mold and there is no way to remove it and still smoke it. You will have to toss it out and try again. 

Mold can be several different colors, from white, off white, yellow, grey, and even orange. 

Other than situations such as mold growth your weed shouldn't go bad. So long as it's properly stored just like all other herbs are vegetables in your kitchen, it will be fine. Like other herbs, the cells will break down and they will oxidize which simply means that the cannabis is less potent over time. So long as there aren't mold spores on it, old weed won't kill you.

Different Types Of Mold On Cannabis 

A few different types of mold can grow on your cannabis plants, all being equally dangerous for someone to consume. Interestingly enough, mold can develop on your cannabis plant at any stage of growth. However, mold is most likely to grow 2 weeks before harvest. 

Imagine how devastating it would be to go through the months of growing just for your hard work to go to waste? We will look at the most common types of mold to grow on a cannabis plant, how to identify it and how to reduce the chance of it growing. Unfortunately, once mold has started growing, your plant is a lost cause, there is no treatment. 

Mold is also more common on certain strains, so it’s always recommended to do your research when choosing what strain to grow. 

White Powdery Mildew 

This type of mold shows up in hot, humid, stagnant air. Often it will grow on the large fan leaves of your cannabis plant, as there isn’t much airflow between the leaves. White powdery mildew can also grow on the stem of your plant, so it’s important to check the entire plant! 

It can also be common in enclosed spaces such as a grow tent. Make sure to inspect your plants often. You can reduce the risk of white powdery mildew by placing a fan in your grow tent, this will help with air circulation. No need to worry about adding a fan to your Grobo, it’s included! 

White powdery mildew looks like someone poured flour on your plant. It’s usually a dull white and looks powdery. It can sometimes be mistaken for trichomes when on cannabis flower. An easy way to tell is to shine a light on the cannabis bud. Trichomes will twinkle in the light, like tiny crystals… whereas white powdery mildew will just look dull.

Luckily if you see this mildew growing on your plant, you can treat it. We recommend pulling off any severely infected parts if your plant.

Next, you can use a fungicide, such as this one. It works on a wide range of fungal issues, so it may have more than one use. 

A more natural way to kill off white powdery mildew is to use neem oil. Neem oil is extracted from a plant native to India, and is very effective at stopping the spread of fungus, and also deters insect pests! 

There are also several homemade fungicides that work surprisingly well: 

Combining baking soda and liquid soap, and a bit of water in a spray bottle works well as a fungicide. While dish soap can work in a pinch, it’s best to get castille soap for this DIY. Using a peppermint scented castille soap is beneficial as the scent will deter pests, however if you are sensitive to the scent of peppermint, unscented will work as well. 

Shockily enough, mixing 1 part mouthwash and 3 parts water in a spray bottle will kill off the mildew. We always recommend testing out this method on a small spot on the plant before spraying the entire plant, as it may cause damage. 

spraying water on your plant can be a quick fix. White powdery mildew is one of the few fungi's that do not spread by water, in fact; it makes it much harder for the mildew to grow. When in a pinch, spraying you plant down with water will make you plant less of an ideal environment for this mildew to grow, which can help stop the spread. It’s best to use another treatment, as this one will simply reduce the spread. 

The images below show what white powdery mildew looks like on a cannabis plant: 

Bud Rot 

The scientific name of bud rot is botrytis cinerea. This mold is typically greyish brown in color. Bud rot thrives in cooler humid environments. In order for bud rot to grow, spores must be present. They can be spread through air, clothing, and water. This is one of the reasons why sterilizing your pruning equipment in-between each cut is so important. 

In order to reduce the chances of bud rot, follow these few steps: 

1. Growing indoors significantly reduces the chance of bud rot. Make sure not to wear any potentially infected clothing, and wash your hands prior to handling the plant 

2. Always sterilize any equipment used on your cannabis plants 

3. Keep an eye on the humidity and temperature. Bud rot will have a harder time developing in warmer, drier conditions. 

4. Keep an eye on dense colas. As there is less airflow, this is another ideal location for bud rot to develop. If you notice bud rot, cut the infected part of the plant off immediately and make sure it does not touch any other part of the plant. Bud rot can spread very fast, so do not delay removing potentially infected branches. 

Below are a few images of what bud rot looks like. Bud rot typically makes the buds easily fall apart when touched.  

White Fluffy Mold 

This type of mold may be caused by a variety of mold species, such as aspergillus, cladosporium, and penicillum. As most of us do not have access to a lab that can test the type of mold, these ones fall under the same category, as they look similar and grow in the same conditions. This mold is commonly white, but may also be shades of grey, green, black, and yellow. 

This mold most often appears after the plant has been harvested, during the drying process. If cannabis is not dried properly, it will have excess moisture, which is the ideal environment for white fluffy mold to grow. Learning how to properly dry. Store your cannabis is the best way to prevent this issue. 

Before we move on to how to properly store your cannabis, here is what white fuzzy mold looks like on cannabis: 

Properly Storing Your Weed 

The best way to avoid the issue of white spots or any other colored spots on your weed is to properly stored in first place.

The best containers to use are glass or ceramic. The reason for this is to guarantee that you have an airtight container so that other smells and flavors don't get transferred to your weed.

You can store your container in a cool, dark place but of course make sure the weed is not wet at all. To that end if you’re using a recently washed container be sure it’s allowed to dry 100% before you place your cannabis in there. Even an incredibly small amount of water left inside the container when sealed up will create an environment conducive to mold growth. 

Having a cool, dark place is important because fresh weed is rich in THC, and CBD but if you expose it to direct sunlight the THC will start to break down into a cannabinoid called CBN which is significantly less potent. That said if it’s exposed to sunlight or any other type of ultraviolet light overtime it will break down and this conversion process will happen but it won't kill you. It certainly won't make you sick if the worst that happened to your weed is that the THC has broken down into CBN. However, it won't have the richness in flavor in the potency that it did originally.

If you store it in something like a ziplock bag just leave it around your house, it might not be something you want to smoke down the line. 

A mason jar is a wonderful way to store your weed. They can be kept in a cool place just as with herbs, for more than six months so long as they’re stored properly. But if you placed your weed in a mason jar for just two days and it's already developed white stuff on it, your jar was far too wet and it’s mold. 

Thankfully, if you have stored cannabis and are worried about any unwanted developments, literally and figuratively, there are ways that you can check.

If you've been storing your weed for a long time, It's important to give it a quick check before you open it and smoke it.

1. If the leaves have dried out and they're powdery, it won't be enjoyable. 

2. If there are any fuzzy white powdery spots growing on it, it’s moldy and you absolutely should not smoke it. 

If you do have moldy cannabis, while it is not safe to smoke, you can use it to make cannabis honey or cherry oil. Between the decarboxylation process and the use of isopropyl or ethanol, the mold spores will be killed making it safe to consume. If you are interested in learning how to make honey or cherry oil, check out our video on it! 

You also want to pull the weed apart in your hands and listen for that crackling sound. If you hear it snap your weed might be too dry. If there’s no noise whatsoever it’s too moist and might very well have developed mold. So if you pull apart your weed and you hear nothing, you might want to consider purchasing new weed. 

Aside from the visual cues your weed might give you, if you open up your mason jar you should get a good whiff. If the weed smells very musty, somewhat like an old locker room, it’s probably moldy so just because you can't see the white spots doesn't mean the mold isn't forming. If it smells like plastic, it was poorly stored or contaminated. 

Essentially, when you open your weed no matter how long it's been in storage, it should still smell like cannabis. The older it is, the less intense the smell will be but the smell itself shouldn't have changed to something else. If it does smell like anything else other than the weed smell you had when you first bought it, something's probably wrong. 

If it doesn't smell and you don't see any visual signs of mold, you should be in the clear but if anything at all is slightly off-kilter, smoking weed with mold on it can cause serious ramifications and should be avoided at all costs. So, check for visual signs of any mold development, smell it, feel it, and listen to it before you decide to smoke it. And if your stash has white stuff on it after 2 days, try a different method of storage.

Do you have any amazing tips for storing cannabis? Let us know in the comments below! 

Are you interested in growing you own cannabis? Check out Grobo.io