Why......

[Perissa]

would the people who rent the yard down the lane from me poo pick their fields every day, rug their horses at night, provide large bale hayledge out in the field yet........

walk around and past the ragwort flowering randomly in the fields....... baffles me - it really does.

 

[Faro]

Baffles me too. Especially as I happen to find ragwort pulling quite therapeutic (ok, so maybe I'm a bit strange!).

 

[quirky]

walk around and past the ragwort flowering randomly in the fields....... baffles me - it really does.

Maybe they are not aware of the dangers?
I know, as a horse owner it's unlikely but it could still be possible.

 

[CeeBee]

Baffles me too. Especially as I happen to find ragwort pulling quite therapeutic (ok, so maybe I'm a bit strange!).

Really? I'm not too far from you, would you like to come to my field for some therapy?

 

[MissMincePie&Brandy]

would the people who rent the yard down the lane from me poo pick their fields every day, rug their horses at night, provide large bale hayledge out in the field yet........

walk around and past the ragwort flowering randomly in the fields....... baffles me - it really does.

Sounds like they are unaware of what it is, and the dangers.
If you don't want to confront them, why don't you type up details of what it is, how dangerous it is to their horses, and what they need to do to get rid of it. Put the note into a plasic sleeve and tie it onto their gate, so they find it next time they are up there.