Itake warfarin can I eat bananas?

Yes, bananas are low in vitamin K. If it is green, it's a problem unless you do it gradually and continually.

You can eat anything, just don't change your diet allot. As long as you stay on a diet that is pretty much the same, like don't all of a sudden eat large amounts of green leafy vegetables, the warfarin dose will be adjusted to what you need.