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How to Grow Thunbergia Plants

Guide to Growing Clockvine, Black Eyed Susan Vine, Brick and Butter Vine, Dolls Shoes, and Thunbergias

Thunbergia plants are half hardy climbing plants.

They bloom from summer to autumn, and usually carry flat or trumpet like flowers.

Thunbergia alata
Thunbergia alata - Black-eyed Susan Vine by Blumenbiene; Creative Commons.

Thunbergia flowers may be white, yellow or orange, and often have a black centre.

Thunbergia Mysorensis
Thunbergia Mysorensis - Clock Vine by Sree314.

There are many different species of Thunbergia grown in the garden. Some of the common names of plants belonging to this genus include Black eyed Susan Vine, Orange clock vine, Dolls Shoes, Clock vine, and Sky vine.

Commonly Grown Thunbergia Species Photographs and Plant Identification

Thunbergia alata

Thunbergia alata
Thunbergia alata (Black-eyed Susan Vine), photograph by Forest and Kim Starr; CC.

Thunbergia grandiflora

Thunbergia grandiflora
Thunbergia grandiflora (Bengal Clockvine / Blue Skyflower / Skyvine), photograph by Bach Arul Ziegen; CC.

Thunbergia erecta

Thunbergia erecta
Thunbergia erecta (Bush Clockvine), photograph by Mauro halpern; CC.

Thunbergia laurifolia

Thunbergia laurifolia
Thunbergia laurifolia (Laurel Clockvine / Blue Trumpet Vine), picture by Forest and Kim Starr; CC.

Thunbergia Growing and Care Guide

Common Names: Clockvine, Black Eyed Susan Vine, Thunbergias, Brick and Butter Vine, Dolls Shoes, Blue Trumpet Vine, Laurel Clock Vine.
Life Cycle: Half hardy annual. Half hardy perennial.
Height: 80 to 320 inches (200 to 800 cm).
Native: Southern and Eastern Africa, South Asia.
Growing Region: Zones 5 to 10.

Flowers: Summer and autumn.
Flower Details: Blue, violet, orange, red, yellow. Dark brown/chocolate/purple/black/yellow coloured centres. Flat; five petals. Trumpets. Pendant.
Foliage: Cordate.

Sow Outside: Cover seed. Start of spring or towards the end of summer. Spacing 10 to 20 inches (25 to 50 cm).
Sow Inside: Start indoors in cooler areas. Use peat pots. Germination time: one to three weeks. Temperature 70°F (21°C). Seven or eight weeks in advance. Transplant outdoors following the last frost; temperature should not drop below 50°F (10°C).

Requirements: Full sunlight or light shade. Rich soil. Moist soil. Organic soil. Provide support. Provide trellis. Regular watering. Prune. Bring indoors for the winter in cool areas. Propagate: cuttings in the spring.

Family: Acanthaceae.
Miscellaneous: The genus is named after the Swedish Naturalist Carl Peter Thunberg. In addition to Thunbergia many other genera have plants are known as Black-eyed Susan, these include: Rudbeckia; Hibiscus and Tetratheca.

How to Grow Black Eyed Susan Vine, Thunbergia

It is best to start growing Black Eyed Susan Vine and other Thunbergia plants indoors when growing from seeds. The process should be started about 7 or 8 weeks before the expected middle of spring.

The seeds should be sown into peat pots and lightly covered. It should take about two or three weeks for Thunbergia seeds to germinate at a temperature of 18 to 25 degrees centigrade (64 to 77°F).

Once ready, transplant the Thunbergia vine outdoors in mid spring (when it always remains above 10 degrees centigrade(50°F)). Ideally, use a spacing of 30 to 50 cm (12 to 20 inches).

Ideally the vines should grow in a sunny or a partially shaded area of the garden. This should have a moist, organic soil.

Caring for Thunbergia Plants

These vines like to have a moist soil, so keep well watered during the growing season.

If you require more black-eyed Susan vine, Clockvine, or other Thunbergia, then you can take cuttings in the spring.

Common Questions

How many members does the Thunbergia genus have?

The Thunbergia genus, commonly known as Black-eyed Susan vine, comprises about 200 species.

Do members of Thunbergia make a good garden or landscaping plant?

Yes, Thunbergia species are popular ornamental plants, known for their vibrant, trumpet-shaped flowers. They're excellent as climbers or groundcovers.

Which Thunbergia species are most frequently grown by gardeners?

The most commonly grown species is Thunbergia alata, also known as Black-eyed Susan vine.

Are members of the Thunbergia plant genus fragrant?

Thunbergia species are not known for their fragrance, but their striking flowers make them highly desirable for gardens.

What is the perfect location to grow Thunbergia?

Thunbergia prefers a sunny to partially shaded location with moist, well-drained soil. They're perfect for trellises, hanging baskets, or groundcovers.

Is Thunbergia invasive in the USA, if so in which states?

Some Thunbergia species like Thunbergia grandiflora can be invasive in parts of the USA. Check local regulations for the most accurate information.

How do I remove Thunbergia plants from my garden?

To remove Thunbergia, uproot the entire plant, making sure to remove all roots to prevent regrowth.

Summary

The Thunbergia plant genus (Black-eyed Susan vine / Clockvine) belongs to the Acanthaceae family. It includes around 200 species of flowering plants native to tropical regions in Africa, Madagascar, South Asia, and New Guinea.

Thunbergia plants prefer warm climates, full sunlight to partial shade, and well-drained soil. They can be grown from seeds, which should be sown in spring, or from cuttings. They're known for their rapid growth and vibrant flowers.

I hope that you enjoyed this guide on how to grow Thunbergia plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Acanthus hungaricus; Wild Petunia, and Ruellia plants.