Grey mold, scientifically known as Botrytis cinerea (or "bud rot" among cannabis growers), is one of the most common and devastating humidity-related diseases affecting cannabis plants. We've seen this fungal pathogen wreak havoc in many grow operations, from small home setups to large commercial facilities.

What to Look For

Grey mold typically appears as grayish-brown, fuzzy patches with a velvety texture on your plants. The trouble with bud rot is that by the time you can visually identify it, the fungus has already penetrated deep into the plant tissue. Here's what to watch for:

• Grayish mushy spots on flowers, stems, and leaves
• Fuzzy, dusty spores with a velvety appearance
• Rotting and shriveled plant tissues
• Black mass of fungal filaments beneath rotted areas
• Wilting flowers
• Water-soaked spots that progressively enlarge

One particularly troublesome aspect of bud rot is that it often begins inside dense buds and works its way outward. By the time you notice exterior symptoms, significant damage may have already occurred to your prized flowers.

Impact on Your Crop

The effects of grey mold on cannabis can be devastating:

1. Reduced yield as infected buds become unusable
2. Diminished quality with compromised terpene and cannabinoid profiles
3. Potential health concerns for consumers if infected material is consumed
4. Rapid spread throughout your grow room, potentially destroying an entire crop in days

Like pruning, dealing with grey mold is another topic that growers will have varied opinions on. What works great for some might not work as well for others. We have found that prevention is significantly easier and more effective than attempting to treat an active infection.

Treatment Options

If you discover grey mold in your cannabis garden, swift action is crucial:

1. Apply appropriate biological controls. Some growers have found success using Trifecta Crop Control Super Concentrate with a dilution of 2oz per gallon, applied every 72 hours until the botrytis is under control. Please do your research and follow instructions on all biological control measures, spraying to late into flower can cause adverse health problems, please be aware of what you are using.

2. Immediately remove and destroy all infected plant material. This is crucial - don't simply toss it in your compost pile. Bury it at least one foot underground or dispose of it according to local regulations.

3. Disinfect all tools after each cut with a 10% bleach solution to prevent spreading spores to healthy plants.

4. Adjust your environmental conditions immediately to create an inhospitable environment for the fungus.

Prevention: Your Best Defense

Generally speaking, potential positives and negatives should be considered when implementing preventative measures. We have found success with these strategies:

1. Environmental Control: Maintain relative humidity below 50% during final flowering stages. This is absolutely critical - if humidity reaches 100% even in a small area, botrytis can develop.

2. Airflow Management: Ensure constant air circulation with strategically placed oscillating fans. Proper plant spacing improves airflow and reduces humidity pockets within dense canopies.

3. Strategic Pruning: Remove excess foliage, especially in lower sections, to improve air circulation. Just don't go overboard - excessive pruning creates its own set of problems.

4. Regular Inspections: Make this part of your daily routine. Early detection is your best ally in preventing widespread infection.

5. Strain Selection: Consider mold-resistant genetics, especially if you're growing in naturally humid environments. While no strain is completely immune, some handle humid conditions much better than others.

6. Bennificial Bacterai: Keeping you soil healthy is key to keeping your plants healthy. Utilizing microbe rich products and proper testing will keep your soil free of unwanted fungi and pests.

Whether to use preventative biological treatments, when to adjust environmental parameters, and to what extent varies depending on your specific grow environment. One important thing to note is that maintaining a uniform climate throughout your grow space is crucial, as even a small local outbreak can quickly lead to widespread infection.