All are grown for clusters of five-petaled flowers like little hollyhocks (Alcea). Plants described here range from erect to sprawling; leaves are typically dark green, roundish to kidney-shaped, about 3 in. across. Basal leaves are shallowly lobed, stem leaves more deeply cut. Provide good drainage. Divide clumps every few years in spring or fall.
S. candida. Native to High Plains. To 23 ft. high, spreading by rhizomes to 112 ft. wide. Unbranched stems bear bluish green leaves to 8 in. across. Crowded spikes of white, 1-in. flowers in midsummer.
S. hybrids. Most sidalceas grown in gardens are hybrids involving S.candida, S. malviflora, and S. oregana (a species native to much of the western U.S.). They form clumps to about 2 ft. wide and bear 112- to 2-in. flowers; bloom all summer if deadheaded. Popular choices include 3-ft. 'Elsie Heugh', with fringed pale pink flowers; 212-ft. 'Loveliness' (shell-pink); 2- to 3-ft. 'Party Girl' (deep pink); 3-ft. 'Rosanna' (deep purplish pink); and 3-ft. 'William Smith' (salmon-tinted, deep rose-pink). 'Little Princess' is compact at just 1115 in. tall and about as wide; its profuse flowers are soft pink.
S. malviflora. CHECKER- BLOOM. Native to Oregon, California, Baja California. May grow erect to 2 ft. high and wide; or may sprawl and spread more widely by rooting at the nodes. Pink or purplish pink, 2-in. flowers in early spring. Moderate water.