Mold On Cannabis Plants: All You Need To Know

Mold happens on cannabis in warm and humid growing spaces, it can develop on a plant’s leaves, buds or roots.

15 June 2020

14 min read

Mold On Cannabis Plants: All You Need To Know

Contents:

1. Mold on cannabis
2. Botrytis
2. a. Identification
2. b. Prevention
2. c. Treatment
3. Powdery mildew
3. a. Identification
3. b. Prevention
3. c. Treatment
4. Root rot
4. a. Identification
4. b. Prevention
4. c. Treatment
5. In conclusion

Mold can happen from in the vegetative stage, flowering stage and even during the drying and curing of buds. It makes them unsafe to smoke, slowly starts killing your plant and can easily infect other plants in the grow room.

1. Mold On Cannabis

It is possible to get mold at any stage of the growing cycle, even in the drying and curing process. This is because fungi need a specific condition to develop.

Mold is a fungus that can affect cannabis plants when they’re kept in a humid and warm condition. It can be treated with fungicides or other homemade remedies, and can be prevented by controlling the environment but because it rots the leaves, roots or buds it can be untreatable or very hard to treat.

Also, mold produces spores (and there’s a good amount of spores in the air anywhere you go). Mold spores can stick on your clothes and can be brought into your growing room. They need only humidity and a slightly warmer condition to start developing.

We recommend keeping a clean growing environment, even if you never got mold or fungi, it is a great way to prevent it.

Most Common Pests in Cannabis Plants

2. Botrytis

Botrytis (also known as bud rot or grey mold) is a type of fungus that affects plants in general. In cannabis, it develops inside the buds and it slowly starts to grow outwards, making it difficult to spot in the early stages.

Botrytis on Cannabis plant.

Bud rot is easier to get when growing outdoors but can affect indoor growers if the temperature and humidity are not controlled.

It can also happen when drying and when curing. If the buds haven’t dried properly they can still hold water, increasing the humidity in the curing jar and ultimately developing mold.

Identification

If you can’t see signs of mold but you notice the leaves drying or if you think the buds are not growing properly it can be a fungus starting to develop in your buds.

It’s really hard to detect bud rot in the early stages because the fungus starts infecting your plant from the inside out.

If you spot any of these symptoms, you should try to take a look inside the buds.

The inside of the buds should be the same color as the outside, if you see brown or grey spots, it will most likely be bud rot.

Prevention

This kind of fungus develops in humid and warm places, to avoid this, it’s crucial to have a good growing space. This means you need to provide good airflow, adjust the humidity level for each growth stage, avoid aggressive temperature changes, and keep your growing space clean.

Optimal conditions to prevent bud rot.

For your drying room, in order to prevent a bud rot, it is recommended to have a relative humidity of 60% and a temperature of around 20-25C.

This can be achieved not only by controlling the environment but also by pruning or performing LST techniques to keep the branches spaced. By having these elements on point, you can guarantee a healthy plant all throughout the growing cycle.

Treatment

If your buds are heavily affected you can still treat them, although you should know that this is a way of allowing the plant to finish the growing cycle and it will not get rid of bud rot. The general recommendation is to dispose of the moldy plant to avoid contaminating the other plants in your grow room.

If you still want to save the infected plant, you should start by decreasing the humidity level and temperature, this will cause the mold to grow slowly. After doing this, you’ll need to spray the affected buds with a mold spray.

The Main Causes Of Bud Rot When Growing Cannabis

If you see the mold continue to grow, your buds will get mushy and completely gray. At this point, you should remove the buds and if it’s really bad you should consider removing it from the growing space or disposing of it.

Note:

Have in mind that the affected buds can be toxic and should not be smoked!

3. Powdery Mildew

Powdery mildew is a kind of fungus that develops on top of the leaves at first. It may look like trichomes to the new growers but it will continue to spread all over your plant.

This fungus is a white powder that can completely cover your plant, especially the leaves, not allowing your plant to perform photosynthesis and ultimately dying it from the lack of energy.

Just like bud rot, powdery mildew produces spores that can easily spread indoors and outdoors and needs very specific conditions to develop.