Indigofera tinctoria (suffruticosa)
I have no idea which forum to post this to. I'm guessing this is the right one, hopefully someone here can help.
Several years ago I bought a plant labeled Indigofera tinctoria (suffruticosa) from a localish herb farm. Every year it came back but never flowered. If it didn't flower this year I was going to rip it out and find something else for the space. However, this year it did flower and it was gorgeous! It is now going to seed, so I did some googling to see if I should deadhead or leave the seeds to mature. Instead of finding this information I learned that the plant I have is tropical or subtropical and should not be a perennial in zone 6.
Now I wonder if I have true indigo, perhaps it's actually false indigo. Can anyone advise how to tell the difference?