Culture
Annual best grown in consistently moist, organically rich, well-drained soils in part shade to full shade. Although sometimes classified as a warm weather annual, this species of Torenia is not terribly fond of hot and humid summer weather. In the St. Louis area, it needs protection from the hot afternoon sun and benefits from a summer mulch to help retain moisture and keep soils cool. As long as properly sited and watered, it will generally bloom from early/mid summer to frost. Start seed indoors 6-8 weeks before last frost date or sow seed directly in the garden just before last frost date. Plants are often available from nurseries in cell/six packs. Set out seedlings or purchased plants 1-2 weeks after last frost date. Young plants may be pinched to promote compact, bushier growth. Container plants may be brought indoors for winter bloom.
Noteworthy Characteristics
Torenia fournieri, commonly called wishbone flower, is a bushy annual that typically grows 6-12” tall and is noted for its ability to bloom well in shady conditions. Species plants feature two-lipped, tubular, trumpet-shaped, bicolor flowers with broadly 5-winged calyxes. Species flowers are pale violet with dark blue-purple lower lips and a yellow throat blotch. Cultivars expand the range of flower colors to include shades of burgundy, pink, rose, lavender and white. A pair of stamens unites at the anthers in a shape resembling the wishbone of a chicken, hence the common name. Toothed, oval, light green leaves (to 3” long).
Genus name honors Reverend Olof Toren (1718-1753), chaplain to the Swedish East India Company.
Specific epithet honors French botanist Eugene Pierre Nicolas Fournier (1834-1884).
Problems
No serious insect or disease problems. Susceptible to root rot and powdery mildew.
Uses
Excellent edging plant for beds, borders and shade/woodland gardens. Containers or window boxes.