Bud rot identifies as gray mold and is a common fungus to growers in high humid climates. It is a severe malady that can make you lose a whole plant if you don’t control it because, well, bud rot spreads fast!
The fungus, known as Botrytis cinerea, thrives in humidity above RH of 50%. Perk the temperature above 70F and you’ve created the most favorite conditions for bud rot to occur.
As it’s also known, botrytis can attack the core of the buds, but they can also attack the stem, leaves, and even seeds.
The thicker the buds, the better the environment for bud rot.
When dealing with such a menacing fungus, you need to know how fast it spreads and if you can save other plants once it invades your grow room.
How Fast Does Bud Rot Spread?
It can spread pretty fast; in less than a week, the mold can infest your whole vegetation if the conditions favor it. Bud rot is spread by touch, contamination by farm tools, and through airborne spores. It’s easy to spread and thus can ravage the whole farm pretty fast.
It’s also pretty difficult to spot when starting in the core of the buds. Growers who don’t do a closer examination of the plants pose a high risk of losing their buds to bud rot in the last two weeks before harvest.
The denser the buds get, the thicker the grow room becomes, and if you don’t rev up the fans, the airflow might be limiting. Poor air circulation makes a conducive environment for the fungus to grow.
What Does The Start Of Bud Rot Look Like?
Bud rot begins as grayish-white but can also be greenish hair-like mold. As it progresses, the foliage will become slimy and soft. The softening of the tissues around the buds kills the supply of nutrients to the foliage, and they begin to dry off.
Botrytis will make the affected areas dry to the touch and easily crumble without much pressure.
The leaves that surround the foliage will be the first ones to signal the impending damage. If you see the leaves around the buds turning yellow and drying off suddenly, botrytis is probably eating the insides of the bud.
In a moist climate, it will progress quickly and might turn slimy before you identify it.
And at that stage, the spores can be spread quickly as the affected fan leaves become dry. Then, the spores will become loose, and even without wind, drop off to either the grow medium or on the moist leaves of the neighboring plants.
Will Bud Rot Spread While Drying?
Bud rot can spread in the drying room. If you dry trim, the extra fan leaves are excellent grounds for the fungus to hide. The mold will make your bud dry into dust.
In less humid climates, bud rot can show as dark, brownish spots on buds. If the drying room is moist, the buds will take the moldy smell, curling deeper inside as the mold eats the core. If you don’t contain it, the drying room will welcome you with the smell of decomposing vegetation.
If the botrytis attacks your buds in the drying room, your healthy buds will be turned into harsh, unsmokable powder or slime, depending on the humidity level in the drying room.
Too high moisture makes for the slimy buds, but when the bud rot attacks a relatively dry grow room, the buds will dry into a powder. In both scenarios, you’re safer throwing the buds away.
The thing with bud rot is that you always want to contain its spread because once it’s got in the buds, you can’t save the buds.
On a living plant, trust botrytis to destroy the whole plant in seven days. If you contaminate the buds when harvesting, the entire drying period, say 10 days is enough to destroy all the hung buds.
How Do You Stop Bud Rot From Spreading?
You can stop bud rot from spreading by chopping the affected buds 3-5 cms below the affected areas and destroying them out of the grow room/drying room. Sterilize the pruning tools before the chop.
After cutting out the affected buds, increase the temperatures to 80F while keeping the humidity below 50%. Gray mold doesn’t do well in a high temperature- low humidity environment.
Keep everything sterilized. Wash your hands, and don’t allow any contact between affected buds and healthy buds.
Improve the airflow in your grow room. Improved aeration leaves no room for the stale environment where botrytis thrives.
Controlling bud rot in a grow room can borrow the skills you learned from fighting Covid19. Maintain hygiene standards in the grow room and sanitize the farm tools.
After removing the affected buds, stuff them in garbage bags and solarize them for a few days to kill the fungus before disposing them outside the garden.
You can spray the plants with 3% H202 to be sure you’ve kept the gray mold at bay.
Keep the grow room clean, not touching other plants after handling the affected buds.
How to Prevent Bud Rot in Cannabis
You can avoid bud rot by growing strains that are more resistant to molds, removing the dead leaves and dying foliage, and keeping the pH at around 6 to foster calcium uptake.
Calcium is essential in creating a solid skeleton. However, a lot of nitrogen and phosphorous makes for soft foliage— vulnerable to the gray mold. Improved uptake of calcium can counter this and enhance the plant’s immunity.
We all have our favorite strains, but if the risk of bud rot is imminent, go for hybrid strains as they are hardier to fungus than pure Indica breed.
Dead leaves are a major breeding ground for the gray mold, and you risk if you keep a mess of rotting leaves in the garden.
If you’re growing in particularly humid conditions, avoid strains that give tightly-packed buds as they’re the most at risk of bud rot during the last two weeks to harvest.
Do not reuse grow medium for new plants after harvesting. You can reuse the grow pots after cleaning and sterilizing it, but empty the contents.
Constantly monitor the humidity and temperature levels and keep the airflow in the grow room at the optimum.
Keep the plants at a safe distance from each other, much like social distance your plants. The space makes it hard for airborne spores to reach the next plant.
You can harvest a little earlier, not waiting for the trichomes to turn amber as the risk of mold infestation is higher then. Translucent trichomes are ripe enough for harvest if you’re climate favors the gray mold.
In conclusion, bud rot spreads pretty fast. Within less than seven days, bud rot can spread in your whole garden, wasting your growing efforts. So keep a close eye on the plants, especially when the buds are at their most dense. If you spot the gray mold earlier, you can curb its spread and save the other plants.