Culture
Easily grown in average, medium to wet, well-drained soil in full sun to part shade. Prefers moist, acidic, humusy soils. Tolerant of wet, boggy soils. Deadhead each flower cluster after all buds in the cluster have opened to extend the bloom period. As the heat of the summer sets in, foliage tends to decline considerably and flowering slows down or stops entirely, at which point plants should be cut back hard. Cutting back plants almost to the ground will promote both new foliage growth and an additional late summer to fall bloom. Divide clumps when they become overcrowded.
Noteworthy Characteristics
Tradescantia, commonly called spiderworts, is a genus of about 65 species of herbaceous perennials from North, Central and South America. They are grown for their showy, three-petaled flowers and attractive foliage. The Andersoniana Group of hybrid spiderworts are some of the most common perennial spiderworts seen in cultivation. They are hybrids of various species including T. virginiana, T. subaspera and T. ohiensis. Cultivars in this group are sometimes given the hybrid name designation Tradescantia × andersoniana.
Genus name honors John Tradescant (1570-1638) and his son John Tradescant (1608-1662), botanists and successive gardeners to Charles I of England.
When the stems of spiderworts are cut, a viscous stem secretion is released which becomes thread-like and silky upon hardening (like a spider’s web), hence the common name.
'Snowcap' is a clump-forming herbaceous perennial which typically grows 1-2' tall. Large, pure white, three-petaled flowers (to 3" diameter) accented by contrasting yellow stamens are borne in terminal clusters (umbels) atop stiff stems. Numerous buds form in each cluster, but individual flowers open up only a few at a time, each for only one day, blooming in succession from late May into July. Arching, iris-like, dark green leaves are folded lengthwise forming a groove.
Problems
No serious insect or disease problems. Young shoots are susceptible to damage from snails and caterpillars. Spiderwort foliage often sprawls in an unattractive manner by mid-summer.
Uses
Borders, open woodland gardens, wild gardens, naturalized areas, rain gardens, or moist areas along streams or ponds.