Build a chicken tractor for your yard so you can direct the efforts of your chickens. It keeps them safe and you can get them to clean up areas of weeds or other vegetation by positioning the chicken tractor.
This is the oh-so-elegant Mrs. "O" She is a Buff Orpington. She has survived some kind of predator attack and limps a bit - oh and her comb is a little shorter but she is still around.