Apple cider vinegar in their water? What does that do?
Also, the are that I am thinking of possibly fencing in is currently covered in ivy, weeds, and a couple larger sapplings. Do I have to worry about the plants harming the chickens? Or will they eventually wear down all the "junk?"
Apple cider vinegar is good for over all health, increases appetite, works as maintenance for killing off bacteria and fungus, it also keeps the crop to a low ph value. The crop is basically a storage for food until it moves into the stomach and it can grow bacteria if it is not kept acidic. 2 tablespoons for maintenance, 3 tablespoons for sick birds. Once a week for one day is a good technique.
It is best to look into what you have growing in the chicken yard and make sure they are not poisonous to your chickens. If they aren't, chances are the chickens will eat them. LOL My chickens turned my garden into a barren moonscape in a few months!
I did a search on here and it looks like nightshade and lilly of the valley are both poisonous? Anything else? Also, it looked like most chickens are smart enough to stay away from either of these anyway?
All bulbs are poisonous. So you might want to transplant any of these. Normally chickens won't touch poisonous plants unless they are starving to death, but why risk it. I have a few really dumb girls and I would not put it past them to eat something that could kill them. Heck, I have seen machine nuts in their poop, tiny pieces of plastic bags go down nice and also packing peanuts! (these can kill them) So it is best to think for your chickens and not let them do the thinking. LOL
look on craigslist and get a used dog run/ kennel . also if you want to keep her out of trees trim her wing feathers on one wing. also get her a buddy,