It was very trendy in the early part of the 20th century to name your cabin or second home (in imitation of the very rich, who named their homes things like "Glensheen" and "La Cuesta Encantada." (Which is what Hearst named his castle, meaning The Enchanted Hill.)

 I'm betting this was just some Duluth Scotsman naming his country getaway, Bonnie Gardens being just the sort of name I found  recommended in a lengthy piece in a Society column about what to call your summer cottage.