Common Name: tweedia
Type: Broadleaf evergreen
Family: Apocynaceae
Native Range: Southern Brazil, Uruguay
Zone: 10 to 11
Height: 2.00 to 3.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Sky blue
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy
Leaf: Evergreen
Fruit: Showy
Culture
Winter hardy to USDA Zones 10-11 where it is easily grown in average, dry to moist, well-drained soils in full sun to part shade. Best in full sun in cool summer climates, but appreciates some afternoon shade in hot summers. Wide range of soil tolerance, including somewhat poor soils. Site in locations protected from wind and if possible rain. If bushiness is desired, pinch stem tips in spring. In the St. Louis area, grow as an annual from seed started indoors 6-8 weeks before last frost date. May also be grown in containers that can be overwintered indoors. Bring containers indoors in fall before frost and place in a bright cool spot with reduced watering until spring. As an alternative, cuttings may be taken from garden plants in late summer for overwintering.
Noteworthy Characteristics
Tweedia caerulea, commonly called tweedia, is native to Brazil and Uruguay. It is a tropical twining vine or subshrub with twining stems that grows 2-3’ tall. Features axillary clusters of 5-petaled sky blue flowers in 2- to 4-flowered cymes from summer to fall. Flowers give way to narrow seedpods and stems exude a milky sap when cut, both characteristics being typical of the dogbane and milkweed family to which this plant belongs. Ovate velvety leaves (to 3” long). Synonymous with and formerly known as Oxypetalum caeruleum.
Genus name honors James Tweedie, 19th century gardener at the Royal Botanic Garden in Edinburgh, Scotland.
Specific epithet means blue.
Problems
No serious insect or disease problems. Flowers are easily damaged when exposed to strong winds and midwestern thunderstorms.