Culture
Best grown in organically rich, medium to wet but well-drained soils in part shade. May tolerate full sun only in temperate climates with consistently moist soils. 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 70F degrees, which unfortunately is a cultural preference that does not fit the profile of a typical St. Louis summer where this plant often labors. In optimum growing conditions, plants will spread by stolons and/or self-seeding in a non-invasive manner to form colonies. Deadhead flowerheads after bloom if self-seeding is unwanted (deadheading may also prolong bloom).
'Roma' is a patented plant that does not produce seed.
Noteworthy Characteristics
Astrantia major, commonly called greater masterwort, is an upright, umbelliferous, stoloniferous, herbaceous perennial (carrot family) that is native to mountain meadows, grasslands, woodland clearings and moist areas near streams in Europe and western Asia. Each flowerhead (2-3" diameter) features dense, compact, domed umbels of tiny greenish-white flowers which form a delicate pincushion-like center subtended by a showy collar of papery, petal-like, creamy white involucral bracts. Flowers bloom late spring to early summer atop wiry, branched, nearly leafless stems rising to 24" tall above an 18" tall basal clump of deeply divided deep green leaves (3-6" long) which are palmately cut into 3 to 7 (usually 5) toothed lobes.
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).
Specific epithet means bigger or larger.
'Roma' is an upright, umbelliferous, stoloniferous, clump-forming masterwort that typically grows to 20-25” tall. Flowers are arranged in compound umbels. Each pincushion-like umbel of rose-red florets is subtended by a showy ruff of papery, horizontal, petal-like, light silver-pink involucral bracts. Bracts usually remain attractive well after bloom. Flowers bloom from late spring to mid-summer on stems rising well above the basal clump of foliage. Leaves are medium green, with each leaf being palmately cut into five doubly serrate lobes. 'Roma' is the product of a planned breeding program in the Netherlands in 1992 between Astrantia major 'Ruby Wedding' (pollen parent) and an unnamed selection of Astrantia major var. involucrata (seed parent). U. S. Plant Patent PP11,470 was issued on August 1, 2000.
Problems
No serious insect or disease problems. Slugs are occasional visitors.
Uses
Part shade areas of perennial borders. Also effective in open woodland, wild or cottage gardens. Good perennial for sun-dappled areas below open trees. Often thrives along moist stream banks (above water level). Plants will spread to fill in open spaces in woodland gardens, but are not considered invasive. May form colonies over time. Excellent for dried flower arrangements.