Bougainvilleas are one of the most colourful plants you could possibly hope to grow because they provide months of colour due to having papery showy bracts. These are designed to attract bees to the small, insignificant flowers. This native of eastern South America is found on the coast of Brazil, then west to Peru, and south to southern Argentina. It needs good light and heat.
This showy and thorny plant was named after Comte Louis-Antoine de Bougainville, an 18th century French admiral and explorer who sailed round the world on a ship called La Boudeuse between 1766 and 1769.
It was discovered by the French naturalist, Dr Philibert Commerson, who came across it in Rio de Janeiro, whilst on the same voyage. It began to be grown in Europe and Australia, before spreading to other warmer parts of the world.
The bees have caused confusion. They’ve been so successful at transferring pollen from one tiny flower to another, causing hybrids, that no one is sure how many species there actually are. Different authorities vary and name four to 18 species. However, there are at least 300 named bougainvilleas and the bracts come in a wide range of colours including white, orange, yellow, lilac, purple and pink, although purples and pinks seem to have stronger constitutions. Bougainvilleas thrive in Mediterranean regions, in Japan, Australia and Morocco. It’s also the official flower of three cities in California, four cities in Guangdong Province in China, a city and a province in the Philippines and of Okinawa, Japan. The islands of Grenada and Guam also boast the bougainvillea as their official flower. This South American star has become a global success.
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Why are bougainvilleas so colourful?
The papery flowers consist of colourful, long-lasting bracts and these provide colour from spring until autumn.
Can you grow bougainvilleas outside in the UK?
The answer’s no for most of us, because Bougainvillea don’t tolerate frost. This means that very few areas of the UK are suited to growing bougainvillea outdoors. However, if you live in the extreme south west of Cornwall bougainvillea can flourish in a sheltered, sunny outdoor spots all year round.
Where to grow bougainvilleas
You have two options. You can plant them in a conservatory or heated greenhouse and, if conditions are warm enough and the light levels remain good, they may bloom for most of the year. Greenhouse pests may become a problem, however.
You can also grow bougainvillea in large pots and these can stay outside for the summer months before being moved somewhere warm and sheltered during winter. Give them a south-facing sunny position once you’ve moved them outdoors. Bougainvilleas prefer slightly acid soil, so add some ericaceous compost to your potting mixture, ideally one part to four.
Why so many colours?
The bees are very adept at producing hybrids in different colours, although botanists believe that most of the named 300 or so Bougainvilleas are derived from just three species - P. glabra, P. spectabilis and P. peruviana. The first two to arrive in Europe in the 19th century, B. spectabilis and B. glabra, have similar bright-pink flowers. They found their way to the colonies and to Australia via the settlers. The first crimson-red reputedly arose in Spain, in the coastal garden of Mrs R.V. Butt and it excited a lot of interest. However, it’s now known to be a natural hybrid involving B. peruviana and B. glabra.
Most garden centres may have one or two bougainvilleas at most. Westdale Nursery in Wiltshire sell a huge range and you can visit, or order on line. They also exhibit at the RHS Chelsea Flower Show. They can supply three sizes of pot, costing between £30 and £70, and the larger the pot the more expensive. They can also advise on which ones will suit you. www.westdalenurseries.co.uk
Lilac and purples Bougainvilleas
Medium-sized purple bracts and dense, intensely green foliage and thorns on woody vine stems. This will require trellis support, or careful training into a shrub or standard configuration. It prefers full sun and warm position.
This has variegated foliage, with a cream edge to the green leaves, and purple bracts.
A vigorous, thorny vine bearing an abundance of
deep-violet flower bracts and deep-green foliage.
A softer lilac-pink.
Vivid pink Bougainvilleas
‘Poulton’s Special’ AGM
Silky looking deep pink bracts, with a twist.
This vibrant magenta pink has dark-green foliage. It’s a medium grower and the flowers have a cascading habit.
A compact Bougainvillea, suited to a large pot, with lots of magenta-pink bracts.
A vigorous and floriferous vine Bougainvillea which is reputedly hardier than most and the thorns are shorter. This will need a trellis support, but it will also cascade down a slope.
This hovers between tomato-red and crimson, so it’s warm rather than vivid.
Cool pastel-pink bracts and darker stamens.
A blush-white with pink edging.
Peaches and oranges
The bracts display shades of apricot, burnt orange, salmon and coral.
Pink bracts mature to orange-brown, gving this a shot-silk look.
A bright-pink double.
Double orange bracts fill the flowers.
Where to plant
Most bougainvilleas are horribly thorny, a device that helps deter grazing animals, so take care where you place them and handle them.
They thrive in full sun, and prefer temperatures of 10 degrees or more at night and up to 38 degrees in the daytime. Their ideal winter temperature needs to be between 7 -10C, or between 44 and 50F.
Plants have a dormant period in winter, although many stay evergreen, and then they have a growth spurt in spring – as temperatures rise.
Always put your finger into the compost to assess how wet or dry it is.
Careful watering is needed because bougainvilleas hate wet roots. Overwatering is the main reason bougainvilleas refuse to flower.
Use rainwater where possible, because tap water tends to be more alkaline.
Water them very sparingly in autumn and winter, allowing them to dry out between each watering.
Once the weather warms up, they may need watering two or three times every week.
When to feed bougainvilleas
Bougainvilleas need two different forms of plant food between mid-spring and mid-autumn.
Give then a regular dose of a high nitrogen fertilizer every week during April and May, to encourage leaves and stems.
Change to a high potash feed once the colourful bougainvillea bracts (and flowers) start to appear and this will encourage more flower.
Vitax Q4 is excellent.
If the bougainvillea leaves start to yellow the plant can be treated with Epsom salts.
Pinch off any faded bougainvillea flowers, back to where they joined the stem, to encourage new buds.
When autumn arrives cut down on feeding and watering when growth slows in Autumn. If temperatures drop your bougainvillea may drop its leaves.
Give bougainvilleas a winter tidy up whilst they’re resting, but do watch the thorns! This will keep them a manageable size. Check their supports, because many need a trellis.
Containerised bougainvillea will bloom happily in the same pot for several years before needing re-potting into a slightly larger pot. Try not to disturb the fragile roots and firm the roots gently. Always leave a two-inch gap between the compost and the top of the pot. Use poot feet and then the water has somewhere to go, should heavy summer rain fall.
These are best taken in early spring, before flowering. Take a stem cutting, about six inches in length, and cut just below a growing tip, using a sharp, clean knife.
Remove all the lower leaves and dip the bougainvillea stem into some rooting hormone powder.
Pot the bougainvillea cutting into a small pot containing good quality compost mixed with some grit or vermiculite for good drainage.
Keep in a warm, humid atmosphere, watering with a fine spray to keep the soil moist but not saturated. The bougainvillea cutting can be planted out once fully rooted, once you can see new growth on the stem.
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