If you’ve been growing cannabis for years, you’ve likely had to contend with the dreaded bud rot fungus. Perhaps you’ve since figured out tricks on how to mitigate what has been described by many marijuana farmers as the most significant issue in cannabis cultivation.
But in the interest of novice weed cultivators and those yet to encounter bud rot fungus, we’ll introduce what it is. We’ll then delve deeper into why this phenomenon is common in cannabis plants.
Introducing Bud Rot Fungus
Bud rot is a botanical fungal disease caused by a fungus called Botrytis cinerea. The disease is known by many other names, including bud mold, gray mold, and botrytis.
Botrytis can affect any plant if the environmental conditions allow it. However, cannabis plants tend to be particularly susceptible to this deadly disease.
As the name implies, bud rot mainly attacks marijuana buds. Without urgent interventions and if the environmental conditions do not improve, the fungus can spread to other parts of the plant and adjacent plants, ultimately ruining your harvest.
Gray mold thrives mainly in cool and humid climates. However, many other environmental and genetic factors can increase marijuana’s susceptibility to this fungal disease.
How Does Bud Rot Occur?
Bud rot is fairly easy to manage if detected early. But as experts would say, it’s better to prevent the disease than cure it. And a huge part of prevention consists in knowing how the infection happens.
Now, botrytis occurs when the Botrytis cinerea fungus makes contact with a plant. While that may sound like an unlikely occurrence, the dusty spores of this deadly mold are quite easily transported. The spores can reach your weed plants via air or water.
When the Botrytis cinerea fungus gets to your cannabis plants, it forms a tear or wound in the external tissues around the buds. The wounds lay the perfect ground for the mold to penetrate the internal tissues of the plant eventually. Worse yet, they can expose your marijuana plants to a host of other diseases.
Once the Botrytis cinerea fungus enters your cannabis buds, the disease immediately begins to break down adjacent tissues as it spreads aggressively to other parts of the plant. Early symptoms of invasion include white and wispy stems.
As the disease progresses, the stems will change to a pale gray before eventually turning into a slimy mass. At this point, the stems will lose their rigidness and ultimately become too fragile to support your cannabis plants.
You may also notice the leaves of your cannabis plants becoming yellowish and burnt. That’s because the fungus is inhibiting chlorophyll production. It’s also at this point that the buds will turn gray-brown slime.
Photo Credit: istock
Reasons Why Bud Rot Is Common In Cannabis Plants[Text Wrapping Break]
1. High Bud Density
Cannabis buds are considerably denser than most plants, especially as these plants approach the flowering phase. That means moisture can quickly become trapped and cause condensation inside the buds.
The resultant moist conditions provide an excellent breeding ground for the Botrytis cinerea fungus.
When the mold makes contact with cannabis buds, it’s almost impossible to expel. The only expected outcome is that the fungus will start to proliferate as it spreads to the other parts of the plant.
2. Numerous Mold-prone Strains
Marijuana comes in many strains. The strains differ across several parameters, including their genetic and phenotypic characteristics.
For instance, Cannabis indica strains are especially prone to bud rot due to their bushy appearance. These plants are shorter and tend to produce denser foliage than their sativa counterparts.
The shorter stature means that indicas are closer to the moisture in the ground, while their denser foliage means they take considerably longer to dry out after precipitation. Both factors can worsen bud rot.
The good news is that there are equally many mold-resistant weed strains that you can grow. Examples include Super Silver Haze, Stress Killer Automatic, Jamaican Pearl, and Sweet Tooth.
3. Improper Spacing
Since many cannabis growers prefer to keep their farms discreet, overcrowding isn’t uncommon.
However, cannabis plants shouldn’t be touched. This ensures that air flows freely between them and around all parts of each plant. It’s also an excellent strategy for minimizing bud rot.
Experts recommend planting marijuana plants at least 6 feet (1.8 meters) apart. Aim for an even wider spacing if you have enough land to spare or if you are growing bushy species like indicas.
In addition to suppressing the conditions required for mold growth, spacing cannabis plants further apart prevents overcrowding and competition for nutrients. Besides, it provides you ample wiggle room when tending to your plants.
4. Adverse Environmental Factors
For outdoor growing, precipitation is perhaps the most prominent environmental factor that can make cannabis susceptible to bud rot. These include aspects like rainfall, snowfall, and hailstorms.
Most plants will recover fast from the wetness caused by precipitation. But since cannabis has denser buds and some species grow into lush foliage, it’s understandable why even a small amount of rainfall can lead to bud rot. For indoor growing, humidity, temperature and air ventilation can compound the adverse effects on marijuana plants as far as botrytis is concerned.
The only way to mitigate these negative impacts is by subjecting your weed plants to the ideal growing conditions. Aim for humidity levels between 40% and 50% and a temperature range between 68 and 77 degrees Fahrenheit. You can lower the ambient humidity and raise the temperature slightly as your cannabis plants approach the flowering phase. This will go a long way in preventing mold and mildew from forming on the plants.
You’d also do well to ensure continuous airflow throughout your grow room. This is especially recommended for indoor growers.
5. Inadequate or Ineffective HVAC
One of the best things about cannabis is that it can thrive outdoors and indoors. Outdoor growing is generally ideal for taller strains, while indoor growing works best for shorter species.
Although bud rot can attack cannabis plants regardless of their growing location, outdoor plants usually bear the brunt of this deadly mold.
That’s because outdoor growers cannot effectively control weather elements like rain and morning due. Therefore, their weed plants can quickly become saturated and promote the spread of the botrytis fungus. That said, even indoor plants aren’t entirely immune. Bud rot might still set in if the HVAC systems are ineffective.
Photo Credit: istock
Bud rot is a common phenomenon in cannabis plants. However, knowing that you can take specific proactive measures to keep the deadly fungus at bay is relieving.