I haven't had a chance to read this whole thread, so I"m not sure if this has been suggested.
We stop in the local grocery stores and go to the produce section. We ask for any of the scrap produce they have, to feed our chickens. They gave us a box of red lettuce the other day (probably 20 heads), they have given us bell peppers, apples, peaches, broccoli, tomatoes etc. It's whatever they have on hand at the time you go. They now save stuff for us.
When you are looking for treats for them, you can't beat free!!
Oh wow, never thought about the stores. I do go to the stands come fall. They usually have a melon or two. Watermelon, or Cantalope. Will have to ask at the stores! This would be great for the winter!! All those greens.