Best grown in organically rich, medium to wet, well-drained soils in part shade. Soils must be kept uniformly moist and not allowed to dry out. Best performance occurs in cool summer climates where night temperatures consistently dip below 70 degrees F… a cultural preference that unfortunately does not fit the profile of a typical St. Louis area summer where the plant often labors. In optimum growing conditions, plants may spread to form large clumps by both stolons and self-seeding.
‘Snow Star’ is an umbelliferous, stoloniferous, clump-forming masterwort cultivar that typically grows 24-30” tall and features domed umbels of white florets subtended by a showy ruff of papery, petal-like, white involucral bracts tipped with green. Long late spring to early summer bloom. Bracts usually remain attractive well after bloom. Medium green leaves are palmately cut into 3-7 (usually 5) toothed lobes. Leaves appear primarily in basal clumps, with smaller versions on the stems. ‘Snow Star’ is often sold as a cultivar of Astrantia major.
No serious insect or disease problems. Slugs are occasional visitors.
Perennial borders. Naturalize in open woodland, wild or cottage gardens.