The Simple Ways – How To Check Your Weed For Mold

Have you opened your bottom drawer lately, only to find a small ziplock filled with weed you bought so long ago that you can’t even remember how long it’s been there? How do you know if it’s still good to smoke? What should you look for? Does weed get mouldy and go bad? If you’re asking yourself any of these questions or something related, you’re going to want to continue reading on. We’ll clear up all of the doubts you may have about the storage of your weed, including its ideal shelf life, how to examine it for mould, and much more!

Recently there have been reported deaths related to contamination of cannabis with a dangerous mould; these findings are not to be taken lightly. If you suspect mould on your weed, you should take these findings seriously and thoroughly examine your product. Failure to examine your weed could be potentially dangerous to your health if it has, in fact, been contaminated with mould.  Mould contains mycotoxins and endotoxins, which together provide a dangerous combination and could negatively affect your health.

See #4 in our FAQ to find out more about these toxins.

Shelf Life

How long does weed last? Under ideal conditions, many say that weed can last anywhere from 1 week to 6 months or longer, depending on the storage method. Now, we wouldn’t necessarily suggest keeping your weed that long, but if for some reason you have a bulk amount that you can’t consume quickly, then looking into storage options that allow you to keep it longer will be essential.

Air is one of Cannabis’s worst enemies when it comes to drying out or becoming mouldy. Take a look at the section on Examining Your Weed For Mold, where we’ll share some storage options for preventing mould growth.

Examining Your Weed For Mold

There are several ways to check if your weed has sprouted mold (Aspergillus). The most truthful indicators of moldy weed will be recognized by using your senses.

6 Signs Your Weed Has Mold

Note: Not all the weed that has been infected with mould will be easily spotted, especially if the dispensary has cut off the mould from the product before packaging it for sale. For this reason, it is essential to buy from a reliable source.

4 Ways To Help Prevent Mold From Growing on Your Weed

If there are no visible spores on your weed or any clear signs of mould but you suspect that it may be susceptible to grow mould, there are a few measures you can take to try and ensure that mould doesn’t begin to grow. Remember, if mould is already present, there is no real way to cleanse the weed of mould; no amount of heat will kill the spores. As a report from 420 Shack reads, ‘The spores can survive pretty much anything this side of hard radiation, So. NO, you cannot kill the spores with fire. The best way to prevent mould is to buy from The Grow House.

Ideal Conditions - Prevent Mold

To prevent mold from growing on your weed you should ensure that your weed is kept under any one of the following conditions.

Seal in an airtight container

Medicine bottles work well if you’re only holding it for a week or less but if you plan to keep your weed longer, look into storing it in an airtight jar. If storing in a jar, it’s advisable to remove the lid daily and check for moisture using special test strips.


As mentioned above, if you freeze your weed it can last months. Remember to vacuum seal the bag it’s in before freezing.

Using a humidifier

In a contained space (some use an aquarium tank) and without allowing the weed to touch the humidifier, you’ll be able to keep your weed from drying out and getting mouldy. Make sure that you are only using purified water in the humidifier and are changing it roughly twice a week. Many reviewers comment that a Blimpie humidifier works really well for this application!

* If using a humidifier, make sure you know exactly how much humidity your weed should be exposed to and for what period of time. Too little moisture in the air will cause the mould to dry out, but too much moisture will be a perfect breeding ground for mould.

The longer you keep your weed, the less potent it will become, the flavour may change, and the rate at which it is smoked may be less, meaning that it will burn faster as it has dried up over time.


If your mold contains a dangerous fungus, it could very well cause your body incredible harm which is why we suggest that if you find mold on your weed you should safely discard it. For those with a weak immune system, any encounter with a dangerous spore of fungus could be deadly. To be on the safe side, we suggest throwing away any weed that has mold on it. Better to be safe than sorry.

Microscopic spores and toxins from the mold, if smoked, will make its way into your lungs and could very well continue growing within the lung tissues. If this starts to happen, the outcome will not be a favorable one.

The amount of weed you have, the thickness of the bag or container you’re storing it in, and the air tightness on that container will all be main factors to whether your weed will mold and roughly how long it will take before this happens.

Mycotoxins are metabolites produced by micro fungi and appear on the exterior of mold spores, in cracks and crevices of the plants. If weed is picked and dried with these, the mold spores will likely stay present and spread. 

Endotoxins are what are released when bacteria is decaying. These are the more harmful toxins which are extremely dangerous if exposed to on a regular basis.

Yes! For periods of shorter storage, you can add an orange peel to the inside of the container where the weed is being stored, always remember that it can’t touch the weed or the mold will spread.

The easiest way to know if your weed is covered in mold and not just trichomes is to look at it. Mold will form on top of the trichomes which will appear as white crystals around the bud; it will resemble a thin fur whereas trichomes have more of a texture similar to resin.

The best way to ensure your weed doesn’t grow mold is by storing it properly, as mentioned above, but also by making sure you are handling it properly. One of the best ways to make sure that you don’t risk cross contaminating your weed is by cleaning out your ‘weed box’. Also, keep note of the temperature of your house and moisture in the air. These two factors will have an effect on the likelihood of your weed growing mold.

Keep it or Throw it?

Good weed should appear green and have a slight purple tinge; white crystals will surround the bud, and the overall product should make a crisp sound when crushed. When smoked, the weed will have a pleasant and distinct aftertaste and earthy smell. If, for any reason, the weed you have doesn’t pass the test of the senses, examine it closer for mould. If you believe your weed has developed mould and you’re asking, can you smoke mouldy cannabis? The answer is yes, you can, but we advise you not to! Smoking mouldy weed could cause havoc on your body and provide horribly dangerous adverse effects.

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