Tweedia
Oxypetalum coeruleum (oks-ee-PET-al-um ko-er-OO-lee-um)
Tweedia is a flowering, broadleaf evergreen, twining shrub or vine from South America. It has heart shaped, gray-green, downy leaves, but is primarily grown for its clear pale blue, star-shaped flowers, which are long lasting and cut well. The summer flowers age to purple. It is related to our milkweeds, but in the dogbane family, and like plants in those families, will exude sap when cut. It can be grown as a perennial in the warmer Piedmont and coastal plain, or as an annual in cooler areas. At maturity, the plant's twining stems will reach a height of 3 feet. The genus name honors James Tweedie, 19th century gardener at the Royal Botanic Garden in Edinburgh, Scotland. The species name means blue. Tweedia is a tropical plant best grown in full sun to partial shade, in average, dry to moist well-drained soil, where temperatures do not go below 37 degrees F. In cool climates, site in full sun, but in areas with hot summers, provide some afternoon shade. Wind and heavy rains can also be an issue. It tolerates a wide range of soils, including somewhat poor soil. To grow as an annual, start seed indoors 6 to 8 weeks before last frost date or grow in containers to overwinter indoors before frost. Place the plant in a bright cool spot with reduced watering until spring. Cuttings can also be taken in late summer for overwintering. Tweedia make excellent cut flowers. Pinch back stem tips in spring to encourage branching. Whether grown indoors or out, the twining branches will need support. Diseases, Insect Pests, and Other Plant Problems: No known insect or disease problems. Flowers are easily damaged when exposed to strong winds or heavy rains.
Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 46 attributes.