658 Tradescantia Andersoniana GroupCommon Names: spiderwort, Virginia spiderwort, widow's tears Family: Commelinaceae (spiderwort Family)
This group of spiderworts consists of several cultivars of complex hybrid origin. The various cultivars share many characteristics, differing mainly in flower color. Spiderworts are erect, clump-forming herbaceous perennials with fleshy, mucilaginous stems and grasslike leaves. Most stand a 1-2 ft (0.3-0.6 m) tall with arching leaves that spread a little less than the height. The three-petaled flowers are about 1 in (2.5 cm) across and borne in terminal umbels, clusters in which all the flower stems originate from the same point. The flowers open in the morning and close by midday, and usually only one flower per cluster is open at a time, but the blooming period lasts for 6-8 weeks. Some of the many cultivars are: 'Blue Stone', 2 ft (0.6 m) tall with clear blue flowers; 'Isis', 18 in (46 cm) tall with dark blue flowers 3 in (7.6 cm) across; 'Innocence', 2 ft (0.6 m) tall with creamy white flowers; 'Snowcap', pure white flowers 2-3 in (5-7.6 cm) across; 'Osprey', white flowers with large feathery blue stamens; 'Iris Pritchard', white flowers flushed with violet; 'Karminglut', deep red flowers; 'Pauline', pink or lilac flowers, 2.5 in (6.4 cm) across; and 'Red Cloud', rosy red flowers. There is also a double-flowered form with dark blue petals: var. caerulea plena.
All of the cultivars included in the Andersoniana Group of Tradescantia were created in gardens by cross-pollinating between and among Tradescantia virginiana, T. ohiensis, T. subaspera. These are wild spiderworts that are native to eastern North America, and grow in moist, open or partially shaded situations.
CultureLight: Spiderwort does best in partial shade. It may need extra watering if grown in full sun. Moisture: Spiderwort prefers moist, fertile soil. Do not let the soil dry out completely. Spiderwort can tolerate even boggy soils. Hardiness: USDA Zones 5 - 9. Some cultivars may be hardy in zone 4, and some may survive in zone 10. Propagation: These spiderworts are propagated by dividing the clumps every 2 or 3 years in spring or fall.
Spiderworts are great perennials to use in beds and borders because they bloom for a very extended period in spring and early summer and again in autumn. The blue-flowered forms are something of a rarity in the summer garden. Use spiderworts in partly shady areas such as under shrubs where many other perennials would refuse to bloom. It is not necessary to deadhead (cut off) spent spiderwort flowers; they will continue to bloom, producing new flowers each morning. Cut back spiderworts close to the ground in midsummer when they finally stop blooming and begin to look a little ragged. They will sprout back and bloom again in fall.
These spiderworts were formerly listed as Tradescantia X andersoniana, but this name is invalid because the authors failed to include the required description when they proposed it in 1935. The name, T. virginiana, also has been used for these garden-origin hybrids, but this name properly refers to a naturally occurring species. See Floridata's What's in a (Plant) Name? for more about the esoterics of naming plants.
Steve Christman 4/12/00; updated 9/16/03, 12/9/03, 3/10/05