I guess if I'm going to photograph gardens, I better learn what I'm shooting. This is from a neighbor's garden, but she wasn't around for me to ask. I do not have a green thumb, and have never particularly been interested in learning...but I do enjoy beautiful gardens.
Could these possibly be a member of the mint family called "Dead Nettle"? There's a lot of a plant that looks like that around here - looks nice with the iris leaves behind it.
I talked to my friend last night, she said it was a ground ivy and could be dried, used as a tea and also edible