How to Grow Thunbergia Flowers, Black-Eyed Susan Vine

About Growing Thunbergia in Your Home Flower Garden

You’re going to love growing Thunbergia flower vines. Also called Black-Eyed Susan vines, they are native to Eastern Africa. This climber has become naturalized all over the world. The vines are sturdy, and the leaves are fuzzy. Thunbergia plants produce an attractive, profusion of daisy-like flowers. Thunbergia flower colors include colors of orange, pale yellow, and white.

While Thunbergia is also called Black-Eyed Susan Vine, it is not even in the same family as the Black-Eyed Susan that we know of as a bush plant, which is Rudbeckia Hirta. These are entirely different plants, with entirely different growth habits.

Thunbergia will look great on a fence, a trellis, mailbox posts, lampposts, or in a hanging container. You can also grow it in a container and let it hang down from your balcony or deck.

Some flower gardeners allow Black-Eyed Susan vines to sprawl and grow directly on the ground as a ground cover.

Thunbergia Flowers Plant Specifications

Flower Colors: Orange, pink, light red, white, and yellow.

Flowers Bloom: Summer through Fall.

Plant Height: As an annual, vines can grow up to eight feet. In frost-free areas, it can be grown as a perennial and reach up to twenty feet.

Ideal Soil pH: Slightly acidic

Plant Hardiness Zones: 10 – 11

Light Needs: Full sunlight to partial sun.

Plant Spacing: Twelve to twenty inches apart.

Toxic Plant? Yes, it is mildly toxic.

Deer Resistant? Yes. The plant has a strong scent, and tastes bitter. As a result, the plants are resistant to deer, rabbits, and other foraging animals.

Number of Species: Approximately 150 species.

Plant Type: Annuals

Native To: Africa.

Botanical Name: Thunbergia Alata

Other Names: Clock Vine

Are Thunbergia Flowers Edible?

NO!!

All parts of this plant are mildly poisonous. Symptoms include abdominal pain, diarrhea, dizziness, seizures, and vomiting.

Keep children and pets away from this plant.

Also, Thunbergia can cause skin irritation, Therefore, we recommend wearing gloves when handling Thunbergia flowers.

Medicinal Uses for Thunbergia Plants

People use Thunbergia plants in a variety of medicinal home remedies. Here are some of them:

Use it to relieve pain.
It aids in heart health.
Use it as an aid in digestion and digestive ailments.
It lowers anxiety and stress levels.

Important Note: As a toxic plant we strongly recommend you do not make home remedies from this plant without the proper training.

Light Requirements

Thunbergia flowers grow best in full, bright sunlight. Select a planting location where they will receive at least six to eight hours of direct sunlight every day. In warmer regions, they grow well in a location where they are lightly shaded from the hot afternoon sun.

Annual Thunbergia Flower Plant Propagation

Thunbergia vines are grown from seed. Black-Eyed Susan seeds can be directly seeded into your flower garden, after the last frost in your area. Or, start them indoors 6-8 weeks before the last frost date.

For indoor starts, we recommend using peat pots, as the plants do not like to have their roots disturbed.

Seeds take a long time to germinate. When planting seeds directly into your garden, mark the area where you plant them.

Thunbergia can be propagated by cuttings. Take a 6 to 8-inch stem from a tender, growing tip, and root it in water.

You can also propagate Thunbergia vines by “layering”. Take a low-growing vine, and bend it carefully to the ground. At about 8 inches from the end of the vine, cover the vine with soil. Stake the vine down, so the wind will not pull it up. Keep the area that is in contact with the soil well-watered. A few weeks later, it will have formed roots. Cut the vine just before the root, and replant your new Thunbergia plant.

Days to Germinate: 10 – 25

Garden Tip: Soak seeds in water overnight

How to Grow Thunbergia Flower Plants

Planting location and soil needs:

Thunbergia Vines are very easy to grow. Grow the plants in full sun to light shade. In hotter regions, plant them where they will receive afternoon shade.

Grow Thunbergia in rich soils to help fuel growth. Before planting, mix in ample amounts of compost. Then, water the planting location.

Fertilizer needs:

Add a general-purpose fertilizer every 4-6 weeks.

Watering needs:

Thunbergia plants do not tolerate droughts very well. Keep the soil well-watered, especially when young, and during hot and dry weather. If grown in containers, be vigilant that the soil does not dry out.

Other steps:

Keep young plants well weeded, until they get established and begin to climb.

Plants need the support of a fence, trellis, or post. Train young plants to reach the support.

How to Grow Thunbergia Vines in Flowerpots and Containers

Vining plants are not popular candidates to grow in flowerpots and containers. But, some people find Thunbergia vines look nice growing down from a balcony or raised deck. And you may find use for them when trained to grow around the railings.

For those who want to grow Thunbergia on a balcony or patio, here are a few additional steps:

Select a sunny location on your patio or deck.
It is important to have a drain hole in the container to allow excess water to drain from the pot.
The plant grows best in slightly dry soil. Keep an eye on the moisture level. Check the plants every few days, especially in extended periods of hot, dry weather.
Keep the soil evenly moist, but not wet. It is okay to let the top of the soil to dry slightly between watering.
When watering the plants, thoroughly wet the soil. Excess water will drain through the hole in the bottom of the flowerpot.

Pruning

The Thunbergia flower plants requires little or no pruning. Simply remove the occasional sick, dead, or damaged leaves as you spot them.

The spent blooms fall off naturally in a few days. However, you can deadhead them as soon as the flower withers. This may encourage more blooms.

Insects and Plant Disease

Thunbergia seldom have problems with insects and disease. White flies and spider mites can infest the plants. Treat with insecticidal soap, if needed.

Also see: Plant Problems – Identify the causes and find the cures, too.