Chickens and weeds

[eggsited chickens]

Ok, I've done some searching and can't really find any weeds that are "Terrible' for a chicken. I have to weed my flower beds and garden and thought maybe I could throw my weeds in with the chicks. I found some weeds that they go crazy over, but I'm running out of those

, so is there any that I should NOT throw in with the chickens? I live in SW Michigan.

Thanks.