One plant started to mold from the inside of the main bud. I think its called bud rot. How can that be? How can I make sure that doesn’t happen again?
I did cut the bud and threw it away. But I am worried now about the other plants.
Best thing you can do is lower your humidity. Watch your humidity during lights out also. When the temperature drops, the relative humidity goes up.
Increasing circulation can help as well. Either thru pruning, spacing, fans, etc.
Some strains are more susceptible than others.
Mold sucks, especially after all that time, money and effort.
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Like Hash said, humidity especially when light are out is crucial…
If you can’t play with it you must improve the immune system…and select mold resistant genetics…
I read ( but never experimented against budrot cause I never run in this problem) that various strains of Lactobacillus are very effective in inhibition of mold growth…
I regularly use it for soil drenched to improve the immune system of the plant and to add life to the soil biology…its awesome.
Lactobacillus are very aggressive…you can make your own
Give it as root drenched and also foliar…
Also Chitosan is been proved as a very effective way to boost immune system and induce mold resistance in plants
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@Grapefruitroop thanks for those links!
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A buddy of mine has grown & worked at a grow shop for about a decade & recommended that I keep spraying BT deeper into flower than I normally would… dude to budrot concerns.
He said there’s a product to add to the BT spray that counteracts Botrytis/budrot:
https://www.centralcoastgarden.com/products/strepto-force
I may try it… but I may just hold off the spraying too. 
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Awesome! I didn’t know about this Streptomyces yet!
Beneficials are always the solution! Do you know which strain of BT? Kurstakii or israeliensis?
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I don’t & he’s just a grow bro & not a Scientist so he’ll probably say “both” to sell me some. 
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How to Prevent & Stop Bud Rot …
Don’t Let Bud Rot Destroy Your Therapeutic Crop
Botrytis cinerea is a parasitic fungus that has two recognizable — and sinister — names common to growers: Bud rot and bud mold. If you’re familiar with bud rot, you know it can destroy an entire crop if left untreated. If you’re not familiar, we have some top tips to help educate you, so you’ll know how to recognize bud rot, treat it, and most importantly, prevent it from occurring altogether.
What Causes Bud Rot In High-Value Plants?
Bud rot develops when its spores germinate in specific environmental conditions. These spores, known as conidiophores, are transmitted by wind and water, and they can infiltrate your grow room via ingress points like the doorway, windows and unsealed intake filters. Spores often hitch a ride inside on shoes, clothes and household pets. Environmental conditions conducive to bud rot include:
Humidity levels of 55 percent or higher.
An environment below 68 degrees Fahrenheit.
Poor air circulation and ventilation.
This is why it’s important that you don’t cram your plants too close together in your grow room. Without enough breathing room and free air movement circulating around your crop, mold spores can more easily spread from plant to plant, leaving your entire grow susceptible to bud rot.
Looking For Signs Of Bud Rot In Your Garden
Bud rot is very difficult to detect in its early stages. Because the infection starts at a bud’s internal stem and breaks it down from the core outward, by the time the mold is visible to the human eye, it’s too late to save the infected bud. Depending on the plant’s life stage and the growth stage of the fungus, visual signs of bud rot can include:
Darkening and discoloration on buds, pistils and/or leaves.
Dry, gray/brown or dark-purple patches.
If you find mold on buds while they’re drying, these buds should be discarded as they are no longer safe for human consumption. Even if there’s no rot present on a recently harvested crop, you’re not necessarily in the clear — bud mold can still develop while your crops are drying.
Take Control Of Bud Rot Prevention In Your Grow
Preventing bud rot isn’t difficult, but it does require attention to detail. Keep your indoor grow at or above a temperature of 70 degrees Fahrenheit so it’ll be too warm for bud mold to flourish. You’ll have to adjust the temperature at various points in the development of your crops, including a slightly cooler environment during the flowering stage, but letting it get too cold can promote the growth of bud mold.
Make sure the humidity in the grow room is high enough for your crops to thrive, but not high enough for bud mold to survive. Humidity of 44–55 percent is your ideal range.
Another key to preventing bud mold in the grow room is having a properly ventilated space where air can easily circulate. Cut down your risk of pathogens and mold spores by outfitting your grow room with a quality intake filter, and clean it regularly to keep it in good working condition. Air flow is an important factor in bud rot prevention — this is why many grow rooms have fans to keep clean air circulating freely. Stagnant air can facilitate fungal development and help it spread even faster among otherwise healthy plants.
In addition to adding an intake filter and a fan (or fans, depending on the size of your grow), you can reduce your risk of pathogens by limiting who and what enters the room where you keep your crops. Remember, Botrytis spores can infiltrate your grow room via clothes, shoes, pets or anything (or anyone) else that comes in from the outside.
It’s also important to maintain a sterile environment in your grow room. Mold spores aren’t the only contaminant that can enter the space and put your crops and, ultimately, patients’ health at risk. Pet hair, dirt and debris can carry pathogens capable of destroying the crops you’ve worked so hard to cultivate. To keep your grow room as sterile as possible, ensure that it is properly sealed all the way around, and close off any unnecessary openings and vents.
Maintaining these ideal conditions is certainly easier for indoor growers, but outdoor growers can also take steps to prevent bud mold, such as:
Increasing air flow within crops by removing some of the leaves on very leafy plants.
Covering crops with tarps or greenhouse poly film to protect them from the rain. When it does rain, shake crops dry afterward.
Choosing a grow location that enjoys a sufficient breeze.
Removing any dead material on the plants, such as leaves or foliage with brown necrosis spots, as these are good starting points for infection.
Your crops are still at risk after they’re harvested, so take the following precautions to reduce your chance of facing bud rot post harvest:
Maintain the optimal temperature and humidity level while your crops are drying.
Dry crops in a well-ventilated space where air can flow freely.
Spread crops out to dry. Even after they’re cut, dense colas and branches can still harbor mold.
Inform your crop processor of any mold issues you may have faced during the grow so they know to inspect the crops carefully, discarding any infected buds.
How To Treat Bud Rot If It Does Occur
When it’s too late for prevention, your only option to save your crops is to treat the bud rot. The most important thing to remember is that an infected bud should never be consumed. Clip all buds you find infected with rot and immediately dispose of them.
The good news is that if you catch bud rot in time, you can usually save the rest of the plant by removing the affected buds. With sterile tools, cut two to four inches below the rotted bud, andre-sterilizing your tools between each cut to avoid any inadvertent contamination. You might be tempted to cut directly below the infected bud, but you need these extra two to four inches to ensure you’ve cut off any additional parts of the plant that might have been infected. Botrytis spreads quickly and broadly, so you can pretty much guarantee that any part of the plant that touched the infected bud is also harboring spores.
Also be sure to sterilize the walls and floors in your grow room. Mold spores can stick to these surfaces and infect crops later if not eradicated when you first discover the problem. A fungicidal soap, or a solution of one-part bleach to nine-parts water can be used for room cleaning.
Bud rot is just one of the parasitic conditions that can wreck your crops and destroy your profits.
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But my issue is outdoors & no elec. power.
Condensation & early rain be damned!
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Your absolutely right! 
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I get average humidity of 68% down here. Fortunately it’s usually above 70 degrees and I have the kick ass ocean breeze pretty much on the daily. Unfortunately, we get May gray and June gloom every year when it’s humid and lower temps gave me botrytis in one zinnia and pm on all of them. I’m hoping for a warm fall as my Dragon’s blood hashplant and strawberry diesels are gonna finish well into November. These make me a bit nervous regarding bud rot outdoors in my hood.
I would assume adding a shit load of fans and some sort of fresh air intake would be key to indoor growing.
@CLOSETGROWTH Nice post! Very informative and thorough.
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Thank you very much!
Also I did read about something that the owners of vineyards are spraying to prevent that disease. Here it is:
Another method commonly used is the application of a bordeaux mixture made up of copper sulfate and slaked line. This is what most vineyard owners use to keep gray mold under control. Copper soap or copper spray is another option that can actually be used all the way until your plant’s day of harvest. This works best when it is sprayed onto your plants each week for ten days. Finally, you can either use sulfur burners or spray your plants with sulfur in order to make the treatment airborne. You can find these at a garden center or nursery.
https://www.ilovegrowingmarijuana.com/marijuana-diseases-gray-mold-bud-rot-botrytis/
On that site they also mention Potassium Bicarbonate (KHCO3) .
Does anybody know something about the two methods?
What is BT?
Also is Lactobacillus (LAB) and Chitosan good for spraying on the leaves? (I use rockwool cubes with ebb and flow)
Where to get Chitosan?
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bacillus thuringiensis
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On the subject of botrytis and the molds and fungi you have to battle to get to harvest…
1)Temps
2)RH
3)pH- pm I battle with water spray pH’d to be acidic (vinegar water) applied to areas surrounding.
Suggested prevention also are neem(cold pressed) and horticultural oils for direct sprays and address first two above?
4) pests- spread disease as well as attack the plant.
Haven’t seen pH listed as a vector to fight the botrytis.
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Botrytis allii
Botrytis carnea
Botrytis cinerea
Botrytis fabae
Botrytis artocarpi
Botrytis anacardii
Botrytis ampelophila
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Yup…LAB and Chitosan foliar but you can also give it to the soil…
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BT is sold easily as Monterey brand caterpillar pesticide
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I did find two products: BT subspecies aizawai and BT subspecies israelensis. Which one is better for bud rot? Can I spray it at end of flower? Will it mess with the taste?
How to use neem oil? I thought it will change the taste of the buds?