Common name: Bush clock vine

Bush clock vine is an evergreen shrub originating in tropical West Africa and now widely cultivated in tropical and subtropical gardens worldwide. 

In cultivation, it is typically 1 to 3 m (3 to 10 ft) tall with branching starting near the ground and the branches long, slender and drooping, creating a compact, weeping, densely leafy canopy.  

Leaves are small, oval with a pointed tip, dark green and arranged along the branches in pairs. They remain on the plant in all seasons, though some leaf fall occurs in areas with a pronounced winter or dry season. 

Flowers are trumpet-shaped, large, purple, blue or less commonly white, with yellow tubes and orange throats. They are borne singly and almost continually year-round in warm and humid climates. Blooms are seasonal in areas with cool winters or a long and pronounced dry season.

Use

It is suitable as a hedge, border, privacy screen or container plant. It can also be trained to cascade over and cover garden retaining walls. However, if cultivated as a hedge, frequent trimmings will result in fewer flowers. The flowers attract butterflies.

Climate

It grows naturally in humid tropical lowland climates, generally frost-free areas with annual lows of 16 to 26 °C, annual highs of 25 to 35 °C, annual rainfall of 1200 to 3500 mm and a dry season of 7 months or less, extending to 12 months with irrigation.

Growing

New plants can be grown from seed cuttings. Performs best on moist, fertile, free-draining clay-loam, loam, sandy-loam and loamy-sand soils of a moderately acid to slightly alkaline nature, generally with a pH of 5.0 to 8.0 on sites with full to partial sun exposure. It has moderate tolerance to drought and salt spray.

Problem features

It is assessed as a  low weed risk species for Hawaii and Florida, respectively, by the Hawaii Pacific Weed Risk Assessment (HPWRA) project and the IFAS Assessment of Non-Native Plants in Florida's Natural Areas.

Books

• Adams, C. D. 1972, Flowering plants of Jamaica, University of the West Indies, Mona, Greater Kingston

• Clay, H. et al. 1987, Tropical shrubs, University Press of Hawaii, Honolulu

• Griffiths, M. & Burras, J. K. 1994, Manual of climbers and wall plants, Royal Horticultural Society (Great Britain), Timber Press, Portland, Oregon

• Macmillan, H. F. 1943, Tropical planting and gardening : with special reference to Ceylon, 5th ed, Macmillan Publishing, London

• Oakman, H. 1995, Harry Oakman's what flowers when : the complete guide to flowering times in tropical and subtropical gardens, University of Queensland Press, St. Lucia, Queensland

• Perry, F. & Hay, R. 1982, A field guide to tropical and subtropical plants, Van Nostrand Reinhold Company, New York

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

• Randall, R. P. 2007, The introduced flora of Australia and its weed status, Cooperative Research Centre for Australian Weed Management, Glen Osmond, South Australia

• Rauch, F. D. & Weissich, P. R. 2000, Plants for tropical landscapes : a gardener's guide, University of Hawaii Press, Honolulu