Astrantia 'Snow Star'

Common Name: masterwort 
Type: Herbaceous perennial
Family: Apiaceae
Zone: 5 to 7
Height: 2.00 to 2.50 feet
Spread: 1.00 to 1.50 feet
Bloom Time: May to July
Bloom Description: White
Sun: Part shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Naturalize
Flower: Showy
Tolerate: Wet Soil


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.

Noteworthy Characteristics

Astrantia, commonly called masterwort or great masterwort, is an umbelliferous, stoloniferous, clump-forming perennial which typically grows 2-3' tall. Flower is a domed umbel of greenish-white or pink florets subtended by a showy ruff of papery, petal-like, greenish or pinkish tinged involucral bracts which extend beyond the flower. 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. Long late spring to early summer bloom. Bracts usually remain attractive well after bloom.

Genus name comes from a Greek word astron meaning star in reference to the flower head shape or from magistrantia (derived from the Latin word magister meaning master or teacher).

‘Snow Star’ 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. ‘Snow Star’ is often sold as a cultivar of Astrantia major.


No serious insect or disease problems. Slugs are occasional visitors.


Part shade areas of perennial borders, open woodlands, path edges, stream/pond margins or wild/cottage gardens. Performs well in moist sun-dappled areas below open trees. Excellent for dried flower arrangements.