A fungus that causes marijuana buds to rot How do you prevent the occurrence of Botrytis cinerea, a fungus that causes marijuana buds to rot? The best course of action for every grower is to proactively find ways of preventing this rot-monger from appearing.  Before anything else, you must identify where the fungus will likely emerge and hibernate. Here are the things you need to do:Set your sights on your indoor garden’s grow room (provided you do have one). There are ...