Ask a Singaporean what a bougainvillea is and they’ll be sure to know! This ornamental plant is a familiar sight throughout the country, not only in parks and gardens but also along our expressways and overhead bridges. With over 300 varieties in cultivation, bougainvilleas have been bred to have blossoms in a range of colours from pinks, purples, reds, whites and even yellows and oranges!
These South American shrubs made their debut in Singapore due to the work of Richard Eric Holttum, the Director of Singapore Botanic Gardens from 1925 to 1949. During this period, he introduced bougainvilleas and other flowering ornamental shrubs and trees like frangipanis to add colour to the botanic gardens’ collection. Later in 1967, the “Garden City” program was launched by the late Mr Lee Kuan Yew to plant up the city’s streets, which eventually led to more bougainvilleas being brought in and planted throughout the island.
Many people mistake the most colourful part of the plant as the flowers but these vibrant, papery “petals” are actually modified leaves called bracts. The true flowers are white or cream-coloured and are nestled in the centre of these bracts. These bracts may serve to attract pollinators and help protect the flower buds during development.
The reason why bougainvilleas are extensively planted in Singapore is that they flower reliably in our hot climate, specifically during our drier periods of the year. These dry periods mimic the environmental conditions of their native habitat: the semi-deciduous and seasonal forests of eastern South America, ranging from Brazil and Peru southwards to Argentina. Other triggers to encourage blooming include limiting their growing space and withholding the amount of nitrogen-rich fertiliser.
Find these seasonal bloomers throughout the outdoor gardens, pruned as a hedge along World of Plants or climbing on the ‘trunks’ of our Supertrees and the trellises surrounding the Supertree Grove.
Written by: Hazri Boey, Senior Horticulturist (Gardens Operations)
Hazri not only surrounds himself with plants at work; he has an abundant collection at home too! Having nurtured a keen interest in nature since young, he might have gone on to become a zookeeper caring for owls or sloths had it not been for his plant identification talent!