If they are suckers from below the graft they are best removed by removing surrounding dirt and pulling them away as opposed to cutting off. I've had good luck when the suckers were young (less than 12").

I'm trying to rescue a friend's 'Sterling Silver' from suckers. Dug it out and the suckers have been there so long (3-6 years?) that it's very difficult to find where they originated. It's like they have merged with the roots. I'm coming to believe it's not worth the effort.

As Iris said, you need to rip off the suckers at the point where they start below ground in order to keep them from growing back. You want to do damage to the tissue so it's can't regrow. Cutting them at ground level just encourages regrowth.

But my question is, how do you know these are "suckers" and not Mr Lincoln sending up new canes?

Thanks for your suggestion. I'll get on it as soon as the snow melts in my garden. Seil, they are coming out below the crown, are spindley and fast growing. I had this before with my Gemini and replaced it.