Well, there are some that they don't eat and some they shouldn't, but haven't noticed them wanting to eat any Jimson Weed, or other members of the nightshade family, except for tomatoes... and they don't eat Sage although wild sage hens do (those are actually a grouse). If you are free ranging chickens in a smaller yard, it is nice to know about things they won't eat, too. I have a lot of sage planted. It can look pretty bare out in the backyard after some of that "free-ranging". And sometimes, the ones they don't eat need to be removed... Nothing seems to like to eat Mallow and it goes to seed very young, so best to pull that one out yourself, before it shortly becomes a major problem... I pick good weeds that have gone to seed from the edges of cropland and take them home and plant the seeds.