I have an approximently 10 year old Nelly Moser clematis. It blooms near the end of May every year and in late summer again. Last year it developed a small underdeveloped purple flower in May that did not fully open at the end of one vine. This year I now have 3 gorgeous purple and white blooms that are on the ends of different branches of the Nelly vine. I believe it is a Tiaga Clematis. How does this occur? Thanks in advance for any comments.
