It may take several years, but as you grow more and more really nice seedlings, some of the old ones will have to go. We have introduced many varieties that we no longer grow. That is a rather hard way to get rid of them however and we no longer grow them as we are not using them for breeding. Many more were culled after several years and finally we got tired of it or it just died. Some were never culled and grew for as long as 14 years. Here we have lots of room and can grow lots of superfluous flowers. But we need to cut back too.
You can always say: "These are my private flowers . " That is what the late Pauline Fanning said when she put some of those flowers into her best in show arrangements. You could ask her for a tuber but it was always: "No".
Yes, we asked. One was called Pagoda as it looked like a red pagoda.