Just like on food, mold can develop on cannabis too, even after it has been harvested. Unfortunately because of the uneven texture and blend of colors, moldy weed is not quite as easy to spot as you would hope, and often develops on the inner part of dried buds so it may not be visible to the naked eye.
Now that cannabis is legal and available in thousands of dispensaries it falls under the same regularity body as food. So it has never been more important for commercial growers to understand how to spot and prevent mold on weed.
What does moldy weed look like?
Moldy weed normally has a light gray or white appearance, it almost looks like fur growing on your bud but sometimes it is difficult to spot the difference between mold and trichomes.
Signs of moldy weed:
- Grey/white dusty texture
- Dark green of back spots on bud
- Powdery mildew on buds
- Slimy or slippery texture
- Dank, damp or musty smell
How to spot the difference between mold and trichomes?
Mold weed will be a more of a gray color than trichomes, it will not glisten as much and will have more of a dull matt appearance. Whereas trichomes glisten as light hits them, they are noticeably sticky to the touch, and if you look at them through a magnifying glass they have bulbous heads that are filled with THC.
Mold can grow on any part of the plant, if it is growing inside the bud itself you may not spot it until you split it open and look inside it.
Mold and trichomes are sometimes very difficult to tell apart, especially when mold is in its early stages. When mold first begins to develop it looks like little white hairs. As you can see from the comparison of mold and trichomes below, to the untrained eye mold could get overlooked until it has developed further, at which point it may be too late to salvage your grow.
The difference between mold and trichomes under a microscope
Using a pocket microscope you can zoom in further and use to to identify any parts of your plant you suspect could be going bad. Below if a comparison of mold and trichomes under a microscope and you can see the clear difference between the two. Zoomed in trichomes look like clear/glassy appendages. During the latter stages of flowering trichomes will appear to have a more cloudy or amber appearance, this is normal and just means the plant is nearing maturity.
Mold on the other hand looks like a spiders web of tiny hairs and does not have the clear bulbous head of trichomes. By investing $15 to $30 in a pocket microscope and carrying out regular inspections on your buds you will be able to spot the early signs of mold and prevent them from spreading.
Use your nose to identify moldy weed
If you have ever smoked cannabis before you will know that it has a distinctive smell. If you are unsure whether or not a bud is moldy, give it a smell. Moldy weed has a noticeable damp, musty smell to it that your nose may recognize before your eyes, so if in doubt follow your instincts.
How to prevent mold during the flowering stage
Mold often begins growing on weed during the during the flowering stage and can come in various forms. The most well-known is Botrytis (bud rot), but other common types that affect cannabis are powdery mildew, sooty mold and fusarium.
It is quite common for mold to go unnoticed until after you have trimmed your bud or during the drying stage.
The best advice is to regularly inspect your buds during all stages of growth and harvest and be extra vigilant once the plant begins to produce buds.
To prevent mold during the flowering stage, follow these tips:
- Use fans and extraction: Using fans will reduce the amount of moisture settling on your plants and keep air flowing.
- Open windows: If you have a window in your grow room open it occasionally to allow fresh air into the room.
- Use a humidity monitor: During the flowering stage a cannabis grow room should be between 40 to 60%. If it is towards the higher end consider investing in a dehumidifier.
- Give your plants space: Make sure your cannabis plants have enough space for air to flow freely in your grow room. If the plants are tightly packed during the vegetative stage this will only become worse once you reach the flowering stage.
- Inspect your plants: This is probably the most important tip. You could do all of the above things and mold may still occur, sometimes it just happens. The best way to prevent a complete disaster is to identify mold in its very early stages. Regularly inspect your plants as they grow and check up on them each time you feed them or as you are training them. Ideally invest in a pocket microscope and use it to analyze anything that arouses your suspicion. This will also come in handy when you are deciding when to harvest marijuana plants.
How to prevent mold during the drying and curing stages
Mold doesn’t just strike plants during the flowering stages, it can also occur after you have cut down your plants. During the drying and curing stages it is just as important to follow some rules to prevent the mold from spreading.
- Wet trim your cannabis plants: Once you have decided its time for harvest, trim your buds before you hang them to dry (this is known as wet trimming). This allows you to get a close up look of each of your buds and inspect them. It also allows you to remove any of the unnecessary large fan leaves that will slow down the drying phase.
- Space out your buds: When you are drying weed, space the buds out properly and make sure that air is able to flow between the buds.
- Use multiple curing jars: When you are curing your weed make sure you use multiple jars. Not only will the extra space allow your buds to cure more effectively, but if one jar becomes infected, you will have another that is safe.
- Inspect your cured bud: During the curing phase, each time you open your bud to burp it inspect it for dampness and any signs of mold. If the bud feels excessively moist, smells funky or looks like it may have any mold on it take all of the bud out for a closer look and allow it to dry out more.
How to prevent weed going moldy during storage
Mold on weed is most often caused by people storing it incorrectly. If you want to avoid smoking moldy weed in the future, follow these guidelines on how to store your bud to keep it fresh.
- Avoid using a refrigerator: If you take your weed out and then put it back in a fridge, the change in temperature can cause condensation. This is one of the most common causes of moldy weed. Instead of storing your weed inside a refrigerator, keep it stored in a cool, dark dry place such as a cupboard or pantry.
- Use a good container: So many people spend a small fortune on their bud only to store it in cheap plastic Tupperware boxes, or even worse, plastic bags. Use a good quality airtight glass jar such as a mason jar. They reduce the amount of exposure to oxygen and keep your bud fresher for longer.
- Use humidity packs: The ideal humidity levels for storing weed are 59 – 63%. Invest in a couple of humidity packs and put one in each jar. Humidity packs from brands such as Boveda are used by dispensaries to keep weed fresher for longer. The packs work using a mixture of water and salts to regulate the humidity levels of a container.
- Store it in the right place: To avoid mold developing on your weed, you should store it in a cool, dark, dry place. Avoid anywhere damp and with bad air circulation such as a basement or garage. Keep them away from sunlight too. Ideally the bud should be kept in the back of a cupboard or closet. Just make sure that there are no radiators directly behind or next to it, as this too can cause humidity and temperature fluctuations.
Can you smoke moldy weed?
First off, if you find any mold on your weed, our advice is not to smoke it.
While moldy weed will probably not cause you any serious harm, it certainly won’t be pleasant. Mold on weed contains mycotoxins, these are toxic metabolite compounds. If inhaled they are unlikely to be dangerous, however they can cause nausea, allergic reactions, wheezing or irritation.
If you’re reading this thinking, “it’s my last bit of weed, I’m willing to chance it”, the taste and effect may not be worth the risk. Mold gives weed a damp, putrid kind of taste that will most likely ruin the experience for you, not to mention the fact that it will be less potent. Mold causes the deterioration of trichomes and cannabis compounds, so the more the mold grows, the weaker your weed becomes.
We should also mention that although the majority of the time you may be able to get away with smoking weed that is moldy without any serious problems. For anybody that has a lung condition such as asthma it should definitely be avoided as it could be fatal.
Its not just moldy weed you should be concerned about smoking either, mold can easily grow on the instruments we use to smoke to which can be just as harmful to our health. If you are a regular bong smoker, prevent your bong from going moldy by changing the water after each use and giving it a regular deep clean every so often to prevent bacteria from building up in those hard to reach spots.
Don’t keep all your buds in one basket
If you have just finished growing your own weed for the season and you are storing lots of it, don’t keep it all together in one container. Divide your bud up into multiple glass jars, that way if mold does affect any of the batches, hopefully the rest of them will be unaffected.
Can you remove mold from weed?
Yes, but it isn’t recommended. It really depends on how much of the weed is moldy, how early you spot it and what the likelihood of it having spread to other parts is.
Small amounts of weed
If you only have a couple of buds of weed in a container and one has mold on it, I would avoid the risk and throw it all away. The spores from mold can spread quickly and if it has been sealed in a container you may not even realize how much of it is infected.
Large amounts of weed
If you are growing your own weed and have an entire plant drying, curing or being stored, and mold has only affected a small portion of your bud you may be able to save the rest of it and throw away the infected part.
Ideally when you are drying your weed you will keep the buds spread out enough that if you do spot mold on one part you can be quite confident that it won’t have spread to all of the others areas.