I finally broke down and made some chicken salad bars. These are basically just hardware cloth in a wood frame designed to let the plants grow through the frame, but keep the chickens from scratching up the roots. I used scrap lumber: 2x4s for the base, and 1x2s for the top (to protect the chickens from sharp wire edges). I made a square and a rectangle because that maximized my wood scraps. The hardware cloth is 1/2” squares.

My hope is that the chickens will have a more steady access to fresh greens, rather than spending a week growing sprouts in a run, and the hens consume the lot in a day and a half.