similar but different. As I understand it, walking stick kale/cabbage is more for fodder, while tree collards are tender, especially where they get some cold (i.e. bay area).
I have had some growing, that reached about 6 feet tall, but withered and died. I don't think they like our humidity and/or sun intensity. I may try them again under a shade house, but I have so many other leafy perennials that are overgrown atm that it isn't a high priority.