Thunbergia Climbing Plants

Thunbergia plants bloom with vibrant flowers.

Unless you live in a warm climate, chances are pretty good that you have never heard of Thunbergia alata, or the black-eyed Susan vine. Thunbergia plants are native to tropical areas of Asia, Madagascar and Africa. Plants are hardy in warmer areas of the United States but can also be grown as an annual in cooler climates.

Identification

Thunbergia plants grow to heights and spreads of approximately 10 feet. Thunbergia alata is a perennial flowering vine that is hardy in United States Department of Agriculture hardiness zones 10 and 11, characterized by average minimum temperatures of 35 degrees Fahrenheit or warmer. In areas of Florida, California, southern Texas and Hawaii, thunbergia plants are evergreen. Gardeners in cooler climates must treat thunbergia plants as annuals. To do so, start the seeds indoors, approximately eight weeks before the last frost of the winter. Plant outdoors once temperatures are warmer than 60 degrees Fahrenheit.

Characteristics

Thunbergia plants have twining stems and foliage that is glossy green with arrow- or heart-shaped leaves. Plants bloom several times throughout the growing season including late spring, mid-summer, late summer and early autumn. Bloom color varies, ranging from warm orange to vibrant red or bright yellow. Flowers average approximately 1.5 inches in diameter and are characterized by soft, five-petaled blooms with a deep brownish-purple center, similar to the traditional black-eyed Susan (which belongs to the Rudbeckia family of flowers).

Planting Instructions

Thunbergia plants can be grown from stem cuttings or from seed. Select a planting site that has well-drained soil and receives full sunlight (at least six to eight hours daily) and some shade in the afternoon. Keep thunbergia plants moist, watering regularly throughout the growing season. Plants should receive at least 1 inch of water per week. Plants produce showy flowers and attractive foliage. Thunbergia is suitable for planting near trellises, in borders, container gardens or as a focal point in the landscape.

Pests

Plants are susceptible to several pests including whiteflies and scale. If you are growing thunbergia plants indoors, watch out for spider mites. Periodically inspect plants for insect activity. If you notice whiteflies, remove affected leaves by hand and spray foliage with a powerful jet of water to dislodge the insects. Scale can be prevented with routine fertilization and regular watering. If you have an outbreak, control it with insecticides

References

• Fine Gardening: Thunbergia Alata
• University of California's Statewide Integrated Pest Management Program: Whiteflies
• University of Missouri Extension: Aphids, Scales and Mites On Home Garden and Landscape Plants

Resources

• Find Your USDA Hardiness Zone