Thunbergia alata

Tried and Trouble-free Recommended by 3 Professionals
Common Name: black-eyed Susan
Type: Vine
Family: Acanthaceae
Native Range: Tropical Africa
Zone: 10 to 11
Height: 3.00 to 8.00 feet
Spread: 3.00 to 6.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Orange-yellow
Sun: Full sun to part shade
Water: Medium
Suggested Use: Annual
Flower: Showy
Leaf: Evergreen

Culture

Winter hardy to USDA Zones 10-11. In St. Louis, it is perhaps best grown as an annual vine that is replaced each spring. Grow in organically rich, fertile, medium moisture, well-drained soils in full sun to part shade. Best with some afternoon shade. Easily grown from seed sown directly in the garden after last frost date. Start seed indoors 6-8 weeks before last frost date for earlier bloom. Also may be grown in containers that can be overwintered indoors in a warm sun room. Cuttings may be taken from favorite plants in late summer for overwintering.

Noteworthy Characteristics

Native to tropical areas of East Africa, black-eyed Susan vine is a tropical evergreen twining vine that eventually climbs to 20’ in frost free areas. As an annual, it will grow to 3-8’ tall in a single season. Features ovate-triangular toothed green leaves (to 3” long) and solitary axillary salverform orange-yellow flowers (to 2” long) with 5 spreading petal lobes and dark throats. Blooms in summer to fall, but best bloom is often in late summer and fall after the hot summer temperatures moderate. A number of different cultivars are available with white, creamy white, light yellow and sulphur yellow flowers. Genus name honors Carl Peter Thunberg, 18th century Swedish botanist.

Problems

No serious insect or disease problems. Watch for scale, spider mites and whiteflies on indoor plants.

Garden Uses

Trellises, arbors, fences or other structures around the home. Also effective in hanging baskets where the vine can twist around the basket supports or in patio containers with a small trellis or obelisk burried in the container.