Black-eyed Susan vine

Sun

Full sun to partial shade; provide afternoon shade in very hot climates.

Water

Keep evenly moist but not waterlogged. Containers may need daily watering during hot, windy weather.

Soil

Fertile, well-drained soil that retains some moisture; use a good-quality container potting mix in pots.

Height

6-10 ft (1.8-3 m) in one growing season; potentially taller where perennial

Spread

3-6 ft (0.9-1.8 m)

Flowers

Summer until frost; potentially much of the year in frost-free climates. Usually yellow or orange with a dark brown-purple eye; cultivated forms also include white, cream, pink and apricot.

Foliage

Evergreen. Soft, green, heart-shaped to triangular leaves with slightly toothed edges, carried on twining stems.

Growth

Fast in warm weather

Care needed

Medium

• Pollinators
• Heat tolerant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   2 ft (0.6 m)

2. After 1 year

   3 ft (1.1 m)

3. After 2 years

   5 ft (1.5 m)

4. After 3 years

   6 ft (1.8 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Invasive in

the US and Australia

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Fast

• Plant outside only after frost danger has passed and nights are consistently mild.
• Provide thin trellis wires, netting or slender canes for the stems to twine around.
• Water at the soil surface when the top layer begins to dry; do not leave pots standing in water.
• Feed container plants every two weeks during active growth with a balanced liquid fertiliser at the label rate.
• Mulch plants in the ground to conserve moisture, keeping mulch clear of the stems.
• In frost-free regions, contain growth and remove seed capsules before they ripen where escape is a concern.

Pruning. Pinch young shoot tips in spring to encourage branching, then shorten stray stems during the growing season. Cut back overwintered plants in late winter or early spring to remove weak growth and fit their support.

Late winter

Sow seeds indoors in warmth, about six to eight weeks before your expected last frost.

Spring

Harden off young plants gradually and plant out after frost danger has passed.

Late spring

Install supports, guide the first stems onto them and pinch tips if plants are sparse.

Summer

Check container moisture frequently, feed regularly and trim stems that stray beyond their support.

Autumn

Remove frost-killed plants, or move a manageable container into a bright, frost-free place before cold weather.

Winter

Keep overwintering plants bright and barely moist; inspect regularly for whitefly and spider mites.

• Train up a narrow trellis beside a sunny patio for seasonal flowers without a large permanent climber.
• Let stems trail from hanging baskets or raised containers, paired with trailing petunias or lobelia.
• Grow over a small obelisk among bedding plants to add height and repeated flower colour.
• Use on removable netting to soften balcony railings or temporarily screen a utility corner.

Garden styles it suits: Cottage garden, Tropical, Modern courtyard, Small-space, Hot border and Urban city garden.

Plant it with: Petunias, Trailing lobelia, Zinnias, Salvias, Coleus and Sweet potato vine.

Wildlife: Flowers provide nectar for visiting insects, including bees and butterflies. It is not a native host plant in the United States, the United Kingdom, Canada or Australia, and its wildlife value does not outweigh its escape risk in susceptible warm regions.

• Spider mites cause stippled leaves and fine webbing, especially under cover: rinse leaf undersides, reduce drought stress and use insecticidal soap labelled for the plant if needed.
• Whitefly and aphids gather on soft shoots: inspect new growth, wash off small infestations and treat persistent infestations with an appropriate labelled insecticidal soap.
• Wilting or root rot follows waterlogged soil: improve drainage, empty saucers and let the surface begin to dry between waterings.
• Few flowers can result from deep shade or excessive nitrogen: move to a brighter position and avoid high-nitrogen feeds.

Not known to be toxic to cats, dogs, horses or people. No particular part is established as poisonous, but species-specific safety information is limited; do not treat the flowers, leaves or seeds as food.

Where it spreads. Invasive in Hawaii and an environmental weed in parts of eastern Australia, particularly Queensland and northeastern New South Wales. In warm, moist conditions it can escape cultivation and smother nearby vegetation; check local guidance before planting.

• Black-eyed Susan (Rudbeckia hirta)

  An upright, non-climbing plant with daisy-shaped flowers and a raised dark central cone, rather than a twining vine with tubular flowers.

• Orange clock vine (Thunbergia gregorii)

  Has similar twining growth and orange flowers, but the flowers lack the dark central eye.

• Blue trumpet vine (Thunbergia grandiflora)

  A much larger, vigorous climber with large leaves and hanging clusters of pale blue to violet flowers with pale throats.

Thunbergia honours Swedish botanist Carl Peter Thunberg, alata means 'winged' and refers to the winged leaf stalks, and black-eyed Susan describes the flower's dark centre.

Propagation. Sow seeds indoors in warm conditions in late winter or spring; soaking them overnight can help germination. Take softwood cuttings during active growth to preserve the characteristics of a particular plant, since seedlings may vary.

Accepted botanical name

Thunbergia alata

Native range

Botswana, Burundi, Cameroon, Central African Repu, Congo, Djibouti, Eritrea, Ethiopia, Ghana, Guinea, Ivory Coast and Kenya.

Measured

Average height 13 cm.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.