Is it too late to transplant Iris and Canna lillies? Will they bloom this year if transplanted? When is the best time to split and replant buttercups?
The best time to transplant iris is in late summer or early fall, however, many people have successfully moved them in spring, too. They may not bloom this year if transplanted. You can transplant cannas as long as the growth is not too large to conveniently handle.
Several plants go by the common name of buttercup. Are you referring to Ranunculus, a spreading, spring bloomer with yellow flowers? This plant grows rampantly and will usually take off no matter when it is transplanted. In general, it's best to transplant spring bloomers in late summer or early fall and late summer bloomers in early spring.