nias are hardy in USDA Zones 4-10.  Although these plants tolerate a wide range of light and soil conditions they are happiest in morning sunshine and moist soil. The plants will tend to be stunted in dry soil and cold winter winds and winter sunshine can actually burn the leaves.  I find that March sunshine can be particularly harsh on the plants.
You can plant Bergenia in spring or fall but they are optimally divided in spring just after they flower.  After about 4 years they will get so big the flowering will decline.  At this point divide them from the crown or start some new ones from seed.

The flowers of the plant come in purple, pink and white and often flower earlier than the new leaves.