Yeah, I've made myself feel sick by eating green potatoes, don't do it, it's not nice. In my defence they were not very green and it was hard to tell.
If you don't earth up then plant them deep and accept the occasional one needs binned, above all (if you are anywhere like where I am) ensure that every single pheasant that even looks at you potatoes dies of high velocity lead poisoning (they scratch them up and leave them on the surface to go green).