I am located in Ontario and the weather is getting...

Avoid letting buds get exposed to wetness – Don’t allow buds to sit in damp or overly humid conditions for long. Protect your plants from rain and shake them if you notice they’re wet from rain or covered with dew. Remove all affected buds immediately – Carefully remove and discard any and all buds that have possibly been affected by bud rot. Don’t let any rot touch other parts of your plant. This helps prevent bud rot from spreading, but it’s not enough if you don’t take care of the environment. Remember, the spores are always around, and it’s just a matter of whether they get the right conditions to grow. Bud rot on an outdoor cannabis bud Other tips to help prevent bud rot… Avoid plant wounds. Avoid injuring your plants, especially in the flowering stage. Don’t leave open wounds to seep out water and nutrients – cover any open injuries with tape or some other “cast” until injury closes up. Avoid pests and keep plants healthy. A healthy plant is much less susceptible to all kinds of infections. Keep some space between plants. Cramming a bunch of plants in a small space can increase the chance of bud rot. Defoliate leafy plants. Remove leaves on very leafy plants. If leaves are touching each other, they’re likely creating wet spots between them. Remove big leaves that are covering or touching bud sites, as well as any leaves that are laying on top of each other. Your plant won’t “mind” if you only remove leaves from leafy areas, and this prevents moisture from collecting into damp spots, while also improving air circulation around buds. Watch out. Watch plants closely for signs of bud rot in the late flowering stage, especially on large or dense buds, and especially after humid or wet weather. When growing outdoors… Get a strain meant for your local climate. If you live in a place that has short summers and gets humid or rainy early in the fall, don’t get a strain that was developed near the equator! There are fast-flowering, cold-resistant cannabis strains which are designed for growing outdoors in more rainy climates. For example, many auto-flowering strains have quick lives – perfect for a short summer before the Autumn rain or frost. A good outdoor strain for those worrying about bud rot might be Auto Frisian Dew, an award-winning, mold-resistant strain made for outdoors. This strain goes from seed to harvest in about 12 weeks. Just plant seeds after the last frost in the Spring, then harvest 3 months later. AutoFrisian Dew is resistant to fungus like bud rot. This strain is quick to harvest and will grow in any climate which has (at least) 3 warm summer months before it starts getting cold or raining. AutoFrisian Dew is a great cannabis strain for many outdoor growers Breezy location – Try to plan your grow spot so your plants get a breeze, but not too much wind. This can be tricky, and it may mean visiting the grow spot a few times before planting. Protect your buds from rain. If you know there will be drizzly conditions, cover your plants with a tarp to protect them from most of the rain. Don’t put tarp directly on plants or you’ll hurt your buds. Install the tarp up above the plants, and make sure it’s held up by the center part, that makes it so rain runs off the sides of the tarp instead of collecting in the middle. Shake plants. Some growers shake their plants on dewy mornings or after rain, so any water drops that form on the leaves don’t become breeding grounds for spores. Fungicides, Neem Oil & Burning Sulfur In the flowering stage, never use fungicides, spray affected buds with Neem oil, or burn sulfur. These common tactics are not effective at stopping bud rot and will make your buds taste, smell and look terrible. Some growers use fungicides made specifically for Botrytis in the vegetative stage. But when it comes to cannabis, fungicides can only be used as a preventative before any buds have formed. If you already have bud rot and can’t fix your environment (which is the best way to kill Botrytis), I highly recommend cutting your losses and taking down the plant. Most fungicides are not effective for bud rot. If you do plant to spray plants, it’s recommended to get one that’s specifically been developed to combat Botrytis. Any treatments for Bud Rot should be applied in the vegetative stage as a preventative. There’s nothing you can spray on your plants after bud rot has already formed. Unfortunately, there aren’t any effective fungicides or other treatments that are safe to use with cannabis in the flowering stage A closeup of a dense bud infected with Botrytis Blight How to Stop Bud Rot from Spreading The inside of dense buds provide a great place for Bud Rot spores to grow, and that’s the main place you’ll find developed Bud Rot on cannabis plants. Once you’ve spotted bud rot, it’s important to act immediately. As soon as even one part of a single bud starts showing signs of grey mold, the rot can spread to the rest of the cola and then to other buds on the plant. If triggering conditions (lack of airflow, wetness) have not improved, a single point of infection can quickly ruin the harvest of an entire plant. Never Spray Your Buds with Anything! Bud Rot Removal Immediately remove all rotted parts and nearby areas. The only way to stop the spread is to remove all signs of mold from the plant, then move plants to a cool, dry area with a nice breeze. Be extremely careful not to let any rot touch any part of the rest of your plant. What Happens Next? You can either… harvest the cannabis plant now let it continue to ripen, but only if you fix the environment If your plant has been affected by bud rot, it means they need less dampness and air that’s more dry. If you can improve the environment, you can allow the plant to continue ripening after you’ve removed the infected buds. However, if you don’t fix the environment it will usually come right back, sometimes even attacking other buds overnight. Here’s how to fix the environment: add additional air circulation lower the humidity (40-50% RH is optimal in the late flowering stage) defoliate leafy plants (remove leaves covering bud sites, through the middle of the plant, and any leaves that aren’t getting light anyway) prevent wet spots on plant If you can’t fix the environment, I highly recommend cutting your losses at this point. If you know that it’s still going to be cool, humid or wet for your plants, it’s recommended you harvest immediately to prevent further buds from becoming infected. Buds harvested early are better than moldy buds! Whenever you do harvest your healthy buds, be extremely careful during the drying process. Normally growers want to slow dry buds, but if you’re worried about mold it’s better to dry them faster, with plenty of air circulation and movement.