I've been using chicken wire to keep out the squirrels and bunnies. It's definitely not pretty but it does the trick. When I make a cylinder to put around a plant (say 2-3 feet tall), I fold the bottom 8" under and seat it under a ring of rocks placed strategically around the edge. I'm not quite sure how long those cages will last (possibly forever but it's a fast changing landscape). I know from experience that especially this time of year, the mammals will eat just about anything (except Euphorbias) unless there's some kind of barrier in the way. They have decimated the native Mammillarias in our local bot garden by simply digging under them and devouring the roots.