Best shrubs for an outdoor tortoise pen?

[Linds]

I'm working on putting together a tortoise pen. I'm planning on making half of it a garden full of yummies for him to snack on (well, I'm a bit late on that one, but what can ya do?), and the rest just grass and small shrubs for him to seek shelter under. Any suggestions on shrubs that will do well in Ontario as well as be safe and functional for my little Redfoot?