I have 5 chickens in a fenced yard. They have eaten every scrap of green except for the scrub plants I don’t want (of course). I do let them out occasionally, supervised, into the backyard, but otherwise, they really don’t get many greens despite being outside and “free” ranging.
For a while I grew sunflower seed fodder inside for them in a nifty hydroponics system I built in my bathroom. They loved it, and it wasn’t all that hard, but for various reasons, I stopped doing it. People tout fodder as a way to save on feed, and it really does, but ironically I discovered that if I gave them too much, they didn’t eat as much food (good, right), and then their shells started getting soft because they weren’t getting enough calcium (bad). They have plenty of eggshells and their feed includes oyster shells, but they were filling up on fodder and not eating the shells or feed. So I pulled back and then eventually stopped the fodder altogether after I cleared the indoor system for cleaning.
So, I researched other ways to provide them with greens in a way that would still get them to eat enough feed/eggshells, I discovered these grazing boxes. Easy to build with scrap lumber. I’ll start with a couple, and stagger planting so that they will only have a little to nibble on as it grows up through the wire. It will still supplement them, but not fill them up because they can’t gorge themselves on it in the mornings when I would dump a container out for them all at once.
I first used barley for my fodder, but it made my bathroom where I grew it smell like a brewery. Then I switched to black oil sunflower seeds, which they LOVED, and because the seeds were bigger, they didn’t clog up the drain holes and didn’t ferment. With the grazing boxes, I may try a combination of the two, and experiment with other grasses. There are some nice mixes available with clover and other grasses for a variety of greens.
Here are some articles I found describing how to build a grazing box. Super simple, but sometimes it’s nice to see one first. I recommend using hardware cloth instead of chicken wire, and 2×4’s should be adequate. The main thing is to keep them from being able to scratch the dirt, and let the shoots get strong and long enough that when they pull on them from above so they don’t just pop out of the soil root and all. I plan to add some of the good compost from my old chicken house that was floorless deep litter and now is thick rich compost that has been sitting for several years.