Seems like the similar ones I have tend to bloom at the same time. Would not be so bad if one were late and the other early. I have Stairway to Heaven, October Sky, and Dream Lover that look very similar. Actually, I had Dream Lover and October Sky planted side by side and they grew into each other. I think now that Dream Lover choked out Oct Sky, because they look exactly alike and I get no rebloom from what I thought was October Sky.