Mine eat just about anything green that isn't poisonous (which I never give them. They're good at avoiding them while they are out but I don't want to tempt fate) Dandelions, clovers, raspberry-bushes and a bunch of other stuff I don't know the English names of.
Fruits are also much loved. I give them treats in form of apples, tomatoes, bananas and carrots, but they don't get much of these though since its so sweet.