patandchickens
Crazy Cat Lady
I've had a lot of volunteers sprout from birdfeeder spillage -- I do not think wild birds are as efficient in vacuuming up the last seed as bored chickens are -- but they've always had teeny small flower heads with very little seed production. Of course this was not in heavily-fertilized-and-weeded garden conditions so it is certainly possible they might do better if you were intentionally planting and growing them.
Pat
Pat