Out here in Alberta Tansy is considered a noxious weed. And if you don't get rid of THEY will and you pay them.I have the odd one in my pasture but rip it out right away.

Nice shot's Tony!
I have some plats still coming up after pulling out a few over several years.
Apparently the leafs and stem are toxic and it makes you wonder if pollen is toxic too?
I'm pretty sure, your bees know best what's good for them.

Here is a link that might be useful: More on Tansy

Konrad, Yeah, I wondered that too. You read about the old-time uses and then read the modern warnings on a lot of plants and it makes you wonder if more people died or got sicker from remedies in the old days than the ailments they were trying to cure. On the other hand, there's much good to say about herbal medicine, and most of the modern pills and such have so many warnings about side affects that I don't take anything. My sisters, on the other hand,literally pass around the advil bottle like they were handing out M&Ms. One took some because a bee stung her on the finger and she said it really hurt. but I'm getting off track.
As for the bees, there are lots of plants that we can't touch or eat but produce perfectly fine honey such as poison ivy. I didn't see tansy listed with plants that produce toxic honey. Konrad, I'm looking foward to seeing you post some more of your great photos.