When I get rich (lol) I want to have a run that is large enough to divide so the chickens only go into one half, with the other half fenced off. I could let grass/weeds/forage crops grow for a few months, then divert the chickens there, while the other half grows.
I did pull something like that off for a while (we have a divided run) but then I decided to get more chickens. The grass I'd managed to hold onto was gone in a matter of weeks.
