Societies, Clubs and Organizations:
https://ahsgardening.org/gardening-resources/societies-clubs-organizations/
Societies by Plant Type
Enthusiasts from around North America focus their energy on specific plants.
Find a plant society that interests you using our list of national plant societies in the U.S.
https://ahsgardening.org/gardening-resources/societies-clubs-organizations/societies-by-plant-type/