My girls get run around the yard inside a movable fencing and they really love to eat the grass and weeds. Since they are used to having the greens and I have only a small space to grow some in the winter for them, any ideas on how to grow enough for three birds fo the entire winter? Like maybe a way of using the homemade brood as a small inexpensive version of a green house? I really don't want them to be unhappy this winter. Any advice would be appreciated.