Are any plants/weeds poisonous for chickens?

hi there! its interesting to see what you are doing on the lottie with your hens as i am hoping to do the same! they love the old brassica stalks.  my hens will be spending some of their days on the allotment and then home for the nights (cant leave them all night as worried about them being stolen when noone is around)  we are makinga moveable run so that they can be rotated around the allotment depending on where there are things growing.  good luck with it all, lou