Michigan indoors always has low humidity at least in my grow, but out doors you cant really stop it. Gorilla Glue has a odd ability to resist bud rot & mold outdoors in Michigan. Its my hypothesis it has something to do with Tropically adapted Landrace strains in its lineage. GG4 has Chocolate Thai in its lineage, while not the same geographic area Chocolate Thai or Thai stick now extinct is a sativa dominant landrace from a humid environment. Durban Poison has yet to go extinct so it has more accurate info It to comes from a very humid area only instead of Thailand its The south African port city of Durban. Both of which are very humid and experience muggy conditions during the majority of the summer. Durban has less rain but high humidity according to leafily the Durban poison strain has quote
"Growers and concentrate enthusiasts will both enjoy the over-sized resin glands which make this strain a quality choice for concentrate extraction. The buds are round and chunky, and leave a thick coating of trichomes on almost all areas of the plant."
What I'm getting to with all this hoopla is Michigan is a rather moist environment, what we typically grow in or near is a swamp. Gorilla Glue Cherry pie and a few other strains like resist mold & bud rot when grown outdoors here. Certain strains just fail less when grown outdoors here and I account for the growth time. Its just the sticky ass bud does better resisting pests mold and bud rot IDK but I think there may be a reason as to why. My Best guess its linked to THCV production.