Common Name: cupflower
Type: Herbaceous perennial
Family: Solanaceae
Native Range: Central South America
Zone: 7 to 10
Height: 0.50 to 1.00 feet
Spread: 0.50 to 1.00 feet
Bloom Time: May to frost
Bloom Description: Light blue to violet blue
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy
Culture
Tender perennial that is winter hardy to USDA Zones 7-10. In St. Louis, it is grown as an annual in moist, organically rich, well-drained soils in full sun to part shade. Soils should be kept uniformly moist. Best bloom occurs in cool summer climates. Flowering may slow down considerably in the heat of a St. Louis summer where some light afternoon shade is best. A summer mulch retains moisture and helps keep soils cool. Sow seeds directly in the garden 1-2 weeks before last frost date or indoors 6-8 weeks earlier. Set out seedlings or purchased plants just before last frost date. Pinch young plants to promote bushiness. Deadhead spent blooms to encourage additional bloom. If flowering significantly decreases in the heat of the summer, cut back plants to encourage later bloom. If sited in a sheltered location with a southern exposure, plants may survive a mild St. Louis winter. Cuttings may be taken in late summer for overwintering.
Noteworthy Characteristics
Nierembergia linariifolia, commonly called cupflower, is a compact tender perennial that grows in a dense spreading mound to 6-12” tall. Cup-shaped light blue to violet blue flowers (to 1.5” wide) cover the plant with bloom from summer to early fall. Finely-cut, stiff, linear leaves to 1/2” long. The Royal Horticultural Society currently considers this species to include the formerly recognized N. hippomanica and N. caerulea.
Genus name honors 17th century Spanish Jesuit professor of natural history and author Juan Eusebio Nieremberg (1595-1658).
Specific epithet means with leaves like the genus Linaria.
Problems
No serious insect or disease problems. Susceptible to tobacco mosaic virus. Watch for slugs.
Uses
Bedding and edging. Beds, mixed borders, rock gardens or along walks. Containers, hanging baskets and window boxes.