Family: Nyctaginaceae

While these vigorous, evergreen climbers originate from tropical and subtropical South America, its cultivars in many colours have now been developed in many other parts of the world. Most have quite vicious, hooked thorns and are able to climb over other plants or supports. Bougainvillea has alternate, mostly ovate leaves, which grow to 15 cm (6 in) long, and produces cream flowers which are insignificant. However, the persistent, brilliantly coloured bracts surrounding the flowers are very beautiful.

Species

Not all of the following cultivars will be available in all areas but there are many more of equal merit to choose from.

B. x buttiana is a hybrid from which many stunning cultivars have been produced. 'Golden Glow', formerly known as 'Hawaiian Gold', has large clusters of golden yellow bracts that turn apricot with age and grows to about 4 m (13 ft). 'Louis Wathen', from India, is a lively tango colour and 'Mrs Butt' (called 'Crimson Lake' in the United States) has large sprays of crimson heart-shaped bracts which deepen to different tones of magenta. The true flowers have a star-like shape. 'Mrs McClean' has star-shaped flowers and orange bracts and 'Scarlet Queen' is a rich crimson like 'Mrs Butt', but the true flowers are not star-shaped. 'Barbara Karst' has a bushy habit, producing masses of brilliant red flowers almost continuously. It will flower at an early age, even in quite small containers. The even bushier 'Temple Fire' grows to only 90 cm (36 in) and is very suitable for containers. Its cerise or rosy violet bracts change to a terracotta-pink with age.

B. glabra is a vigorous scrambler with smooth, bright green leaves, weak thorns and purplish pink bracts, smaller than those of many of the cultivars. Cultivar 'Sanderiana', paper flower, produces an abundance of papery, vivid rose bracts. This thorny climber can grow to 6 m (20 ft). 'Magnifica Traillii', previously known as 'Magnifica', has splendid, bright purple bracts. From the Seychelles, it grows to 8 m (26 ft) and is tolerant of frost down to -7°C (19°F).

B. spectabilis is a striking species, with an interesting woolly covering on its leaves, short spines and rich purple bracts to 5 cm (2 in) long. The following cultivars have been developed from this species: 'Lateritia', an extremely vigorous, spreading rambler, with terracotta red bracts which age to a bronze-gold, and the very beautiful and prolific 'Scarlet O'Hara' whose deep burnt orange bracts age to orange-scarlet, then to crimson. The parentage of some of the new cultivars mentioned below is unknown. Most of these new cultivars are less vigorous than the older types and are suitable for container planting. 'Easter Parade' grows to 4 m (13 ft), with rather pointed, soft pale pink bracts. 'Killie Campbell' grows strongly to 6 m (20 ft) and its deep red bracts change from coppery red to ruby red, and sometimes to cyclamen. 'Orange King', also a strong grower, has large bundles of coppery bronze flowers, ageing to apricot and flesh pink. 'Snow Cap' is a very new development with intriguing variable bracts: some varieties have both white and purple bracts, while others have just white or purple. All of the varieties are worth planting. 'Surprise' (sometimes known as 'Mary Palmer'), with pure white bracts and magenta bracts on the one plant, is one of the most beautiful of all the bougainvilleas. At times the colours are on separate branches, at others they are on the one stem. Highly sought-after double-flowered cultivars have also been developed and these are often extremely striking. 'Klong Fire', to around 2.5 m (8 ft), has beautiful double carmine bracts, 'Thai Gold' has double golden yellow bracts, while 'Pagoda Pink' is in the most delightful pink, tinged with lavender. 'Bridal Bouquet', also known as 'Limberlost Beauty', has double white bracts, edged with bright pink. When grown in semi-shade, the bracts of this cultivar take on a green shade, resulting in a very pretty and unusual floral display.

Cultivation

Although bougainvilleas are frost-tender they are able to survive light frosts and are sometimes grown in gardens in the far south. In the north they make excellent plants for cool conservatories and greenhouses. Under glass, grow in a soil border or in pots or tubs of soil-based potting compost and provide maximum light.

Water well in the growing season and less in winter. Outdoors grow in a sunny spot with well-drained soil. Bougainvilleas do best in a light, sandy loam, requiring additional food and water during spring and summer. Prune immediately after flowering by cutting back the stems to within 6 cm (2 in) of the older wood. This will encourage the growth of new wood and abundant flowers in the following season. From time to time, remove the older stems at the base of the plant. Propagate from hardwood cuttings taken in spring or summer. Some species root more reliably than others.

To grow as standards, set a thick stake, such as 80 mm (3 in) galvanized iron piping or 80 x 80 mm (3 x 3 in) hardwood, in a concrete block. The stake should be about 2 m (6 ft) high from ground level. Remove all but the main stem from a small or semi-advanced plant and tie it to the stake. Rub the side buds off as they appear. When the plant reaches the top of the stake, allow the top growth to spread, and continue to remove the side buds along the main trunk. Trim the head to a globular shape. Bougainvilleas can also be grown as hedges. They often become very dense, producing a blaze of colour throughout spring and summer. Some of the newer hybrids flower almost continuously. They can be trained to a low groundcover growth with wooden frames, and the more vigorous will quickly climb trees and walls. If trained on trellises, they need strong support. Do not plant them on old fences.

Climate

Zone 9 and above.