Over Chitted Potatoes

just rub them off   they will be fine

Are the shoots white?

If so, sounds like they've been chitted in the dark, or at least with insufficient light to keep them short and purple/green.

Best to err on the side of too much rather than too little light, although as the others have said they'll still grow, they just won't have the head start they would have had if planted with healthy chits.

Given that it's very cold at the moment you may be better off delaying planting for a week or so, although your spuds won't produce much in the way of chits in that time even in good light.

Some people take the chits off and plant those instead of the potato.

Could you expand on that one please? Can't imagine it applies to long white chits snapped off at the base.

I don't know if it changes as they get longer, but if you look carefully at a chit you can see embryonic roots growing out sideways at the base.  The potato doesn't grow roots out the bottom and leaves out the top, each chit is like a little mini-plant ready to go, if you snap them off really carefully.  My American friend was just describing how he grows his and said "... then I throw the eyes in the hole..."

Now if you snap the chits off and throw them away, the potato has to start all over again activating some new growing points, and it's not got much food left in store because it's all gone into the very long ones.  You'd have to be very careful planting the long chits as they will need to go into a narrow deep hole and the top of the shoot not be too far from the surface.  Might be worth a try though.

http://www.growveg.com/growblogpost.aspx?id=180

This person describes planting sprouts, if you ignore the fact that they are doing it from shop bought potatoes, very bad, etc...  sounds more like placing cuttings and having the tips actually above soil so that's tricky in the open ground right now.

I've only done it indoors.