Moldy Weed: How to Tell If Your Buds Are Rotting Away

Moldy weed has long been one of the worst things that can fall into the laps of unsuspecting recreational users and medical cannabis patients.

The reason why moldy weed is so infamous is because consuming it can be really damaging to one’s health, although this mostly happens when their well-being is already deteriorated.

Several studies confirm the potential of mold to harm people through cannabis consumption, and there are also cases in which medical marijuana patients likely died due to moldy weed.

More than a year ago, scientists from Davis University in California warned of the dangers of mold-infested cannabis, especially when consumed by patients with leukemia, lymphoma, AIDS and other conditions that rely on immunosuppressive therapies.

These findings pushed the same team of researchers to join forces with a cannabis testing firm named Steep Hill to analyze cannabis samples from various dispensaries and producers.

What they found is extremely unsettling and shocking, but also somewhat expected at the same time:

UC Davis and Steep Hill scientists confirmed that there was some form of mold in each and every sample of cannabis they tested.

Even worse, 90% of the samples tested positive for bacteria such as E.coli (Escherichia coli) and other dangerous fungi.

After the results of Globe and Mail’s cannabis testing have been published (which found significantly lower levels of mold), there was a huge public debate on whether cannabis testing labs are subjective and whether they’re selling positive ratings for compensations.

Since mold is mostly transparent and miniscule in size, it is usually undetectable by the naked eye. A person will be able to see some types of mold, but definitely not all of them.

But is mold dangerous for people who don’t suffer from any health condition?

Given the fact that most people never smoked sterilized and vacuum-packed weed, you most likely smoke buds contaminated with miniscule amounts of mold on the regular.

So, what gives?

How come you were never hospitalized as a result of that? Aren’t we all taught that all living organisms live just fine in symbiosis with bacteria and fungi?

What are molds?

Molds are a very divergent group of fungal varieties that use hyphae for vegetative growth. The hyphae are thread-like “branches” of molds, and for the most part appear translucent and fuzzy.

The connected network of hyphae is called mycelium and is usually considered as a single organism.

Molds use spores for reproduction, and these spores usually have pigment (making them appear colored), which is why they are easier to spot with a naked eye. The production of spores in molds is typically excessive and abundant.

Molds are responsible for biodegradation of bio-materials (also called decomposition), by releasing hydrolytic enzymes which degrade complex biopolymers into simpler substances that can be consumed by the molds via the hyphae.

Just like all other species of fungi, they don’t rely on photosynthesis for energy, but instead degrade and consume the organic material on which they live, using a process called heterotrophy. Animals and humans exist in a very similar fashion.

These types of fungi play a vital part in biotechnology and creation of various foods and drinks, and also antibiotics and other pharmaceuticals.

Certain types of molds can cause allergic reactions in humans (especially to their spores), and certain pathogenic molds can be responsible for diseases if they inhabit our organism, or if we inhale or ingest the toxic compounds (mycotoxins) that are created by these pathogenic molds.

What happens if you smoke moldy weed?

There are people out there saying how the tip of a joint burns at a high enough temperature to incinerate all mold and bacteria.

The tip usually burns at around 900°C (1652°F), which is a very high temperature indeed, but by the time smoke enters your mouth and the rest of the respiratory system the temperature is around 50–60°C.

If you truly believe that the temperature achieved by smoking or vaping kills all of the bacteria, here is an excerpt from a study I cited above, that proves otherwise:

“Some may argue that the temperature of inhaled samples (50–60°C) suggests that inhaled smoke may be sterile. However viable organisms have been cultured from smoke even after water filtration, suggesting that temporary exposure to elevated temperatures or attempts at filtration are probably insufficient to protect the compromised host.”

If you aren’t aware that you are allergic to a specific type of mold, you should tread carefully. Mold allergies produce a variety of symptoms: From a slight skin rash, to a full-blown asthma attack.

Here are some of the health issues that can arise if you smoke moldy weed:

  • Fatigue
  • Weakness
  • Headache
  • Chest pain/heartburn
  • Asthmatic attack
  • Dizziness
  • Heavy cough

Even though these symptoms also happen as a general side-effect of smoking in general, if you notice them on a prolonged or unexpected scale, you should get evaluated by a doctor.

How to tell if your weed is moldy

So, there are 3 situations in which you can find yourself with visibly moldy weed:

  1. You are growing your own cannabis and you notice mold appearing on it
  2. You finished with growing, but you didn’t dry and cure properly
  3. You bought moldy cannabis

The first case is the best scenario because you can still do something to fight the mold.

In the second and third scenario, the only thing to do is say farewell to your stash.

However, if you see visible mold/bud rot, I implore you not to consume that weed.

You should avoid consumption because you simply cannot tell exactly what type of mold it is and how dangerous it is.

Mold is usually discolored and pale when compared to the rest of the plant.

You’ll be able to see patches of white (or black) mold appearing on your buds, which means that they aren’t getting enough air (or that your plant is lacking proper airflow).

What does moldy weed look like?

Sometimes it can be very difficult to notice mold developing on cannabis, especially if you have big bushy plants. Mold develops in plants because they create the perfect environment for it (humidity and moisture are key factors).

These are the four main molds and fungi organisms that you can encounter on cannabis:

  • Botrytis (gray mold)
  • White powdery mildew/mold
  • Aspergillus
  • Cladosporium

Only the first two are visible by the naked eye. Botrytis is gray mold, while the second one gets its name from being really white and blanched.

However, mold can also appear in black, and many variations of brown and yellow.

In some instances, it can also have a spider-web appearance to it.

How to get rid of bud rot when growing weed

You can remove the white powdery mildew from the leaves by wiping them with a wet cloth.

Wipe extremely delicately and patiently to avoid spreading the spores on the rest of the plant, because otherwise, it will just appear again.

After that, make sure that your plant has enough airflow and treat it with some SM-90 to prevent future spore growth. Mix 1 part SM-90 to 5 or 6 parts of water, and place the blend in a sprayer.

Spray all of the leaves with the mixture, you can even spray the mixture during flowering phase because it’s completely safe and it will do absolutely no harm in the future when you are smoking your buds.

As for black bud rot, or regular black mold and gray mold, there isn’t really much you can do.

Cut of all the infected parts as soon as you notice them, as only cutting will stop the spread.

Handle the rotten pieces you have removed extremely gently as you don’t want them to release the spores onto the remaining healthy pieces of your plant.

If you’re growing a plant that is extremely bushy and has very little airflow in its canopy, it can be good idea to remove the biggest leaves in the bottom and middle parts of the plant.

You’ll definitely want to do this during the flowering phase as your nugs need to get enough sunlight to grow really thick and juicy.

Dehumidifiers also reduce the chance of bud rot and mold ever appearing on your plant as they require moist and humid environments.

The best thing you can do with your weed once you harvest it (before the curing and drying processes), is to sterilize your cannabis with a mix of 3% hydrogen peroxide (H2O2) and water.

How to sterilize weed with hydrogen peroxide (H2O2)

The process of sterilizing weed with hydrogen peroxide is actually very simple.

You will need the following:

  • 3% hydrogen peroxide (H2O2), around 200-250ml (1 cup or 6-8 oz)
  • A bucket that can take about 20 liters (5 gallons)
  • About 20 liters of water
  • Drying rack, or any other type of hanging device
  • Electric fan(s)

Mix the 3% hydrogen peroxide with water in the bucket. Take the weed you harvested, and sink all the colas under the water. Keep them sunken for about 3-5 minutes.

You will notice a white greasy substance starting to float up, which will indicate that the hydrogen peroxide is removing all the mildew. Remove it with a sponge or a piece of cloth.

After that take the weed out, cut all small leaves with scissors (give the nugs a haircut), and hang them on the rack to dry out, preferably with access to sun and fresh air.

Turn on the fan (or even multiple fans if you have them), because if they don’t dry in the next couple hours they might start developing mold and fungi again, which would be a real drag.

Now that you’ve sterilized the plant material, you should also sterilize the glass jars where you will be storing your weed and cure them.

This will lower the chance of mold developing in the jars even further.

Here is a great video that detailedly shows how to do this.

Categories Basics

2 thoughts on “Moldy Weed: How to Tell If Your Buds Are Rotting Away”

  1. I’ve bathed and I even tested with UVC regularly before cutting. I just bathed but I still see the mildew on the drying buds. Thoughts?

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