Alright earthlings, Rev here today with an article that can help you avoid powdery mildew, and the dreaded bud rot. In my just shy of half a century of growing and smoking cannabis, I have smoked a shit-ton (Texas measurement LoL) of powdery mildew and Bud Rot mold. I’m still alive.
It’s not dangerous as far as I know to smoke powdery mildew or Bud Rot, but it sure as hell ruins flavors and disappears potency (resin production). Bud Rot, is particularly insidious, and it behaves like a cavity in your teeth. It rots out the inside of flowers while keeping the outside looking okay for a while. By the time you know about it, it’s already done major damage. Look for the bud leaflets to look limp-ish and have a kind of gray/brown color. This is a sign Bud Rot is afoot deeper in your buds.
Caterpillars are major causes/catalysts of Bud Rot. At night moths land on plants laying eggs that become caterpillars. They grow up and take residence inside of buds, pooping and eating, causing primo conditions for Bud Rot. Orb web weaving spiders, wasps, and yellowjackets all hunt moths, or caterpillars and are good guys. BT (bacillus thuringiensis) powdered products work pretty well to kill caterpillars, but good old fashioned hand removal helps a lot too.
Avoiding Powdery Mildew is Normally as Easy as This
Just obey the number one rule here and you will likely be powdery mildew free, indoors or outdoors. Do not import clones from outside sources. No matter how sure anyone is that their clones are pest free, don’t believe it, unless you know for a FACT it’s true.
They may also in fact be pest free, but only because someone used neurotoxin type poisons on them. These highly effective poisons are highly effective because they kill so well—wanna smoke some? No, you do not.
If you are growing outside in the ground, you should grow from seed plants anyways. Seed plants are far more capable outdoors in the ground than clones are. Seed plants outdoors in the ground are more likely to avoid pests of any kind than clone plants are; which includes avoiding powdery mildew.
Even close inspection of clones still doesn’t reveal the threats that can lie within the plant. Powdery Mildew sets itself up like just under the outer skin layer of the leaves making it “invisible” to even magnified inspections. Make your own clones to grow from using good seeds and select the plants you love to live on in clone form for harvest after harvest. Visit Kingdom Organic Seeds – True Living Organically Grown for some killer beans baybee.
Avoiding Powdery Mildew and Bud Rot Outdoors
If you are growing in your back yard or on your property outdoors, there are some things you should pay attention to if you want to avoid powdery mildew and bud rot. Bud Rot can actually be brought about by several types of fungi/mold. Botrytis (fungus) is usually the most likely suspect here. Always avoid growing your weeds near, or down-wind from anything like zucchini or squash plants. These attract a lot of powdery mildew.
- During the fall season of the year before growing, like now, observe all the local flora and fauna around where your plants will be, for pest issues like powdery mildew, mites, etc. Especially those plants that are normally up-wind from your growing plots.
- Do not select topographical spots in bowl-like depressions thinking they are hidden away better. Moist air tends to settle in low spots longer. These spots are also most likely to freeze if it is super cold at the start of spring.
- Backyards in your basic neighborhoods are not well suited for growing plants that harvest later than the first week of October. Too much wind blockage. Selecting spots with excellent exposure to almost constant winds is fantastic—these plants will also require more water.
- Dead-still, foggy/misty mornings are what you do not like. Especially when it warms up quickly. If you get a day or two of this and you only have, say several plants, a leaf blower works awesome to blast off excess moisture. This must be done early morning while it’s light, but before sunrise proper.
- In greenhouses use a dehumidifier if it’s easy to do so; absolutely. Bare minimum though, you need to make sure the greenhouse has the best venting you can manage.
Avoiding Powdery Mildew and Bud Rot Indoors
It’s easier to control mold/fungi indoors than outdoors. If you just get unlucky outdoors, weather-wise, and there are a lot of spores in the air, you can be boned through no fault of your own. Shit happens. Indoors you can control your humidity, and that’s the big enchilada right there. Keeping your humidity below 65% always, even during lights off, is what I do indoors.
- Never bring houseplants or any plants you just purchased or whatever, anywhere near your cannabis garden. Even in the same house is bad. If you already have houseplants, you likely don’t need to worry, just inspect them closely with a mag glass for mold or pests. Most commercial plants are infested with something.
- Keep your distance between lights and plant tops in check. Running your best and biggest flowers way too hot will sometimes cause them to “summon” bud rot. I like 18 inches minimum distance from lights.
- Don’t use synthetic nutrients on your plants. This causes a level of stress in the plants that makes it very hard for them to do battle with any pests, including mold/fungi. Synthetic fed garden usually gets destroyed utterly by mold once it has a foothold.
- Filter any air intake from outside. Passive intake is the best and can be filtered easily.
- You never, ever, want to be doing anything outside, in nature, coming into contact with lots of plants, then go visit your gardens indoors. No outdoor gardening before tending your indoor plants.
- Visiting other grower’s gardens is always risky, shower and change after, before going into your own gardens. Likewise, don’t let other growers come from their infected gardens to visit yours.
When It’s Too Late to Avoid Powdery Mildew
The product Serenade can really save your ass in a pinch. This product isn’t good for avoiding powdery mildew, but it is pretty good at knocking it down for a bit of time. I use this stuff if I ever get powdery mildew—I haven’t had any in many years—just to treat the plants until harvest. Then after harvest I eradicate the powdery mildew from my gardens. Don’t use Serenade once you are two weeks from harvest. The flavors will suck otherwise. Serenade will not totally eradicate the mildew itself.
Once harvest happens, and you have no more plants, you can just use a vaporizer in your garden with all the fans and venting ON. Use 1 tablespoon of bleach per gallon of water in the vaporizer. Set it to about 1/3rd power and let it run for a whole day. Avoid breathing the bleach vapor, best to just leave it to vaporize and come back later after it’s vented out. Within 8 or 10 hours of bleach vapor, there won’t be any living mold or spores in the room.
When it’s Too Late to Avoid Bud Rot
Bud Rot is a bitch, no two ways about it. You’re basically mostly boned once you have it. Severe pruning to allow more airflow in the flowers and removing decayed bud/mold will normally save about 25% of your harvest. If Bud Rot is a problem in a garden, or a tent, increase air movement and air extraction. Outdoors select windy locations (very windy). In the distant past when we did guerilla growing, we often grew right on top of cliffs or steep hills that received major updrafts from wind.
Indoors all you can really do is as above and severely prune the plants, add some dehumidification to your garden to slow the progression of the Bud Rot. Little mini dehumidifiers like in the photo above work well to skim off several percentage points of humidity in smaller garden rooms/tents and use little power.
Afterword with Rev
I got an email about one of my recent articles that had a photo of one of my bongs in it—The Little Red Engine Bong. That wasn’t my personal bong I like to use most. That is a bong for outside on the porch, or in the garage, or to travel with. A Bic Bong if you will; disposable, sort of. There’s my major bong in the photo, Thor’s Hammer, heh heh. “It’s hammertime!” 15 inches tall made from triple thick-ass glass, classic design and perfect smoke to air ratios. Easy to clean, man, what’s not to love! LoL.
Here’s another article you should check out since we are talking pests here: Fungus Gnats in Cannabis Growing – Skunk Magazine. Okay then dudes and dudettes, looks like I’m outty for now. Catch me back here next Tuesday at SKUNK for another article about our favorite plant. L8r G8rs.
- REv 😊
I'm The Rev, and I have been with SKUNK for about a decade now. I hail from Southern California, spent mucho time in Northern California, and now reside in Southern Oregon; always coastal. I am an all natural style cannabis grower and I have written a couple books on the subject - check out True Living Organics 2nd Edition on Amazon - I have been growing for over 45 years, and I have been breeding cannabis for over 30 years. Check out kingdomorganicseeds.com to see some exotic selections. Growing connoisseur cannabis is what I teach mostly, growing it in living soil without using liquid organic nutrients to feed the plant. I am also a highly skilled synthetics grower, hydroponics, aeroponics, DWC/SWC/NFT, Ebb and Flow, and soilless, but I cringe when smoking synthetic grown herbs, so for the last 15 years or so I preach the artisan style of all natural growing, specializing in container growing. Cheers and welcome aboard.