I don't belong to any real garden clubs or societies, but that doesn't stop me from coming up with a few that I'd like to belong to, including...
Society for the Preservation and Propagation of Old-Time Gardening Wisdom, Lore, and Superstition (SPPOTGWLS or “the Society”) - Members of the society are interested in the old ways of gardening and in preserving them for future generations.
Green Bandana Garden Club - Not quite a society, this is just an ordinary garden club. Members know they are invited to join when they see a green bandana in their garden. Henceforth, they generally can be found carrying green bandanas with them wherever they go.
Society of Gardeners Aged 50 and Over (SGAFO) - An invitation to join the Society of Gardeners Aged 50 and Over is perhaps the most coveted in all of the garden blogging community. We are always on the look out for new members. I myself am a recent inductee.
Vicar Ellacombe Garden Literary Society - If ever there was someone to name a garden book, excuse me, literary society after, it is Vicar Ellacombe, also known as Canon Ellacombe. He wrote, "I suppose no one who loves his garden is entirely without books on his
favourite subject; and, indeed, I have always found that a lover of
gardens and flowers is also more or less a lover and reader of books."
Garden Bloggers' Book Club - Now defunct, I started this club in 2007 or so and actually encouraged people to virtually join by reading the selected book of the month and posting about it on their blog. I would rather belong now to the Vicar Ellacombe Garden Literary Society.