A number of dwarf cultivars of Bougainvillea suitable for containers or small gardens are now on the market, which means that most Queenslanders will be able to find a spot for a Bougainvillea or twenty.
Dwarf forms can also be mass-planted as a groundcover in a sunny location. cut back from time to time with hedge-trimmer to keep dense. With suitable cultivar selection and training, bougainvilleas can also be grown as hedges, as shrubs or standards as well as trained up fences, trellis or pergolas. If you have a very large garden or acerage, you may consider growing one of the more robust varieties up a large tree.
Dwarf bougainvilleas are more naturally restrained in their growth characteristics. They can still be prickly but usually the thorns aren't as savage and if kept neatly pruned shouldn't be a major deterrent to planting them.
There are now many varieties of dwarf bougainvillea on the market. The Bambino® series is very popular (More information at their consumer website www.bambinobougs.com.au) but there are other dwarf types.
'Temple Fire' is an old one and still one of the smallest and shrubbiest. Varieties like 'Purple Cascade' or 'Little Caroline' have a low growth habit suitable for planting at the edges of the retaining walls or containers where a draping effect is wanted.to drape down, or in.
Note that "dwarf" is a relative term and most will still spread/climb quite sunstantially if pruning is totally neglected.
Bougainvilleas as hedges
Bougainvillea are among the most prolific flowering plants for warm climates and can be trained in a variety of ways including hedges.
Like almost any flowering species, constant pruning to a rigid geometrical shape (the so-called formal hedge) will tend to remove developing flowers. If a softer shape is acceptable, bougainvilleas would be suitable for a very colourful and drought-tolerant hedge with a moderate amount of maintenance.
The key to curbing the bouginvilleas tendency to climb and maintain a bushy form is regular light clipping in between flushes of flower.
It will also help to chose a less vigorous and more shrubby variety than the stereotypical climber.
Is there a thornless Bougainvillea?
As far as I can determine, there is no Bougainvillea which is 100% thornless. Occasionally one reads of a thornless variety, only to read elsewhere that it does produce some thorns, or reduced thorns.
B. arborea, a species introduced into the US trade in the 1990s, is possibly the closest thing to a thornless Bougainvillea. While commonly referred to as such, even it can produce thorns on juvenille growth, apparently (see notes in the Virtual Tour of the AOS Garden). This species is also interesting as it's said to have a more tree-like habit of growth than most Bougainvilleas, plus fragrant flowers. Unfortunately, I don't know of any nurseries selling this plant in Australia as yet (if you do, please get in touch!).
[Update: In pictures of advanced specimens I've seen recently, B. arborea looks rather like a crepe myrtle (Lagerstroemia) in flower. If it has a longer flowering season, and/or doesn't sucker like crepe mrytle, it might be a superior substitute.]
Meanwhile, dwarf varieties readily available on the market in Qld tend to have very small thorns. With a little common sense, they can be used in a variety of landscaping applications.
More Online Information
The following links are for general information and further research - some species or cultivars referred to in international publications may be unavailable in Australia
A comprehensive factsheet from University of Hawaii at Manoa (PDF)
Osceola County Extension Service, University of Florida
Bougainvillea (Paper Flower)
Pictures of Bougainvillea being cultivated in a variety of ways in Thailand and Vietnam (at www.flowerpictures.net)
Popular Varieties [Under Construction]
Although there are dozens (if not hundreds) of varieties in exisitence, there are a limited number routinely available on the market in Australia. Over time, information and pictures of the most regularly-encountered varieties willbe collected here.
Unusual growth habit for a bougainvillea withtrong upright canes with closely packed leaves that can be readily maintained as a shrub or even a formal hedge. Intense pink flowers. Sometimes listed as "Smartie Pants" or "Smartie Pants" and known overseas as 'Pink Pixie', 'Hawaiian Torch' or 'Torch Glow'.
Bougainvillea 'Smartipants' with other shrubs form a screen. Brisbane, January 2014
Bougainvillea 'Smartipants'. The lower part of the plant demonstrates the response to regular pruning, while the upper portion illustrates the unpruned growth habit. Brisbane, April, 2016
The best-known variegated variety grown locally. Rasberry-red bracts.
Part of the Higher Ground website, Texas USA. To help their Bougainvillea
'Rasberry Ice' survive the Texan winter, these gardeners dig it up every year!
A variegated bougainvillea (probably 'Rasberry Ice') spilling over a brick wall
Known in USA as 'Mary Palmer'. Easily recognised by separate pink and white inflorescences borne by the same plants. From a distance, 'Snowcap' looks like two different varieties growing together.
Bougainvillea 'Snowcap'. Coopers Plains, April 2014
Bouganvilleas in the landscape
Bouganvillea do not flower well in shade, but the tree cover here is clearly not dense enough to affect flowering adversely. The dominant cultivars here appear to be Bambino® NonyaPBR (mauve) and PedroPBR (orange). QEII hospital, Brisbane, May 2014. A few pink, purple and white blossoms suggest that this planting originally contained a greater range of colours than the lavender and orange that now dominate and illustrates how cultivars can differ in vigour.
Superficially this looks like 'Snowcap', but closer inspection suggests it may be 'Klong Fire' (aka 'Mahara'), with some branches sported to a paler coloured inflorescence similar to Limberlost Beauty (aka 'Cherry Blossoms'). Sunnybank, March 2014. This plant is likely about 40 years old.
Different inflorescences from the above plant
Some old, vigorous varieties are capable of climbing tall trees
Planted in the wrong place or not properly controlled by training or pruning, vigorous types can be a problem. Here, long thorny canes reaching over the fence present a hazard for pedestrians.
Bougainvillea Sunvillea® Rose, Cream and Pink varieties. Images courtesy of Suntory® Flowers
Propagation and production
Pacific flora database
of the National Tropical Botanical Garden, USA. Select Bougainvillea arborea from the "Choose A Plant" menu
Monte Negro Bougainvillea spinosa
. Flora y Vegetacion de la Patagonia, Argentina
Universidad Nacional del Nordeste, Argentina. Students of horticulture who don't speak Spanish may nevertheless derive some useful information from this document (PDF)
Possible Misspellings: Boganvillea, Bouganvillea, Boganvillia, Bouganvillia, Boganvilla. In older texts it may be spelled Bougainvillaea.