Bougainvillea is the plant that punishes kindness. Water it generously, feed it richly and give it deep fertile soil, and it will grow lush green metres of thorny stem with barely a flower. Plant it in full sun, let it dry out between drinks and feed it sparingly, and it disappears under sheets of papery magenta, scarlet, purple or white for months on end. Once you understand that the colour comes from controlled stress, everything about growing it makes sense.
The colourful parts are not petals at all but bracts, modified leaves surrounding tiny cream flowers, which is why they last so much longer than true blooms. In frost free Australia, bougainvillea will flower on and off from spring until the cool of late autumn, and in the tropics it barely stops at all.
Quick facts
| Botanical name | Bougainvillea glabra and hybrids |
|---|---|
| Type | Evergreen climbing shrub |
| Height | 1-6 m depending on variety and training |
| Position | Full sun, the hotter the better |
| Soil | Well drained, slightly acidic pH 5.5-6.0; poor soil improves flowering |
| Flowers | Colourful bracts spring to autumn |
| Climate | Frost free warm temperate to tropical, to about 2°C |
Understanding bougainvilleas
Bougainvilleas originate from the tropical regions of South America and are revered for their vibrant bracts, which frame small, inconspicuous white flowers. These bracts come in a plethora of striking colours, including magenta, purple, orange, and white. Their ability to flourish in harsh conditions makes them a robust choice for both novice and seasoned gardeners, and a natural companion to the other hardy tropical plants that handle wind and heat.
Because periods of dryness actually stimulate flowering, bougainvillea is close to ideal for xeriscaping and water-wise beds, sitting comfortably alongside our other drought-tolerant plants for a Brisbane garden.
Choosing a bougainvillea
Covering fences and walls
For a classic curtain of colour, Bougainvillea Purple Cascade from $25.95 pours vivid purple bracts over fences, pergolas and retaining walls, and being a glabra type it is among the tougher and more cold tolerant choices. Bougainvillea White Cascade from $24.95 does the same trick in crisp white, a genuinely elegant option against dark render or brick. For the wider range of options at that job, see our guide to the best plants to soften fences and retaining walls.
Bold reds
Bougainvillea Red Dragon from $25.95 brings deep, saturated red on a vigorous frame, while the old favourite Bougainvillea Scarlet O'Hara from $25.95 is famous for enormous flushes of scarlet crimson and real vigour, ideal where you have serious space to fill.
Pots and small gardens
Not everyone wants six thorny metres. Bougainvillea Smarty Pants from $16.95 is a compact, free flowering type suited to large pots and smaller courtyards, where a container conveniently restricts the roots and keeps the plant in almost constant colour.
Planting
Choose the hottest, sunniest position you own: a minimum of six hours of direct sun, with a north or west facing wall being ideal since reflected heat drives flowering. Drainage is non negotiable, so mound the soil 20-30 cm in heavy clay or go straight to a pot. Bougainvillea also prefers slightly acidic soil, around pH 5.5 to 6.0, which mimics its native ground. Dig the hole twice the rootball width, disturb the roots as little as possible because bougainvillea resents root damage, and plant at the same level as in the pot.
Space plants 2-3 m apart along a fence, and set a sturdy trellis or wires in place at planting; stems do not twine on their own and need tying in while young. Water in well, then begin the tough love. In pots, use a premium free draining mix in a container 40 cm or wider. In frost prone districts, plant in spring so the roots get a full warm season before their first cold test, and throw a sheet over young plants on the worst nights; it is cheap insurance for a plant that will outlive the fence it climbs.
Ongoing care
Watering: Deeply but infrequently. Let the soil dry out between waterings; in the ground an established plant may need nothing beyond rain. A slightly wilted bougainvillea about to be watered is often a bougainvillea about to flower.
Feeding: Lightly, with a low nitrogen, flower promoting fertiliser in spring and midsummer. High nitrogen lawn foods nearby are a common cause of all leaf, no colour.
Pruning: Prune hard after each flowering flush, cutting flowered stems back by up to a third, since new growth carries the next display. Remove dead or weak stems at the same time to promote air circulation and sunlight penetration. Plants can also be espaliered flat against a hot wall, where reflected warmth pushes flowering even harder; our guide to espaliered trees covers the framework and tying technique. Wear proper gloves and long sleeves; the thorns are not a rumour. Tip prune young plants often to build density.
Common problems
Lots of leaves, no flowers: The classic complaint, and almost always too much water, too much nitrogen or too little sun. Cut the kindness, move the pot into full sun and flowering resumes within weeks. Our guide to why your plant isn't blooming covers the same diagnosis across other flowering species.
Leaf drop in winter: Normal in cooler districts, where plants behave semi deciduously. As long as stems stay green and firm, spring regrowth will be rapid.
Caterpillars (bougainvillea looper): Notched, chewed leaves overnight. Pick loopers off by torchlight or spray with Dipel, a bacterial control safe around pets and birds.
Aphids and spider mites: Less common but possible, especially on soft new growth or in hot, dry, sheltered corners. Regular inspection and an organic oil or soap spray keeps both in check.
Fungal problems: Powdery mildew and root rot follow poor airflow, crowded planting and wet feet. Good spacing and restrained watering prevent nearly all of it.
Frost damage: Blackened tips after cold nights. Wait until all frost has passed, then prune to healthy wood; established glabra types usually recover from light frosts. If you garden somewhere genuinely cold, our list of frost tolerant plants in Australia offers alternatives that will not need a sheet thrown over them.
Other climbers worth considering
Bougainvillea is the loudest climber you can plant, which does not always suit a quiet courtyard. For evergreen coverage with perfume instead of thorns, our guide to Trachelospermum jasminoides covers star jasmine, while climbing fig care tips deals with the self-clinging option for bare walls.
Where bougainvillea grows in Australia
Bougainvillea is close to a signature plant of warm Australian gardens, and it thrives on exactly the conditions that defeat most flowering climbers - heat, poor soil, reflected light and neglect.
| Location | How it performs |
|---|---|
| Darwin and tropical Queensland | Spectacular, and vigorous enough to need real management |
| Brisbane, Gold and Sunshine Coasts | Excellent, flowering heavily through the warm months |
| Perth | Outstanding - dry summers and sandy soil suit it perfectly |
| Sydney and coastal NSW | Very good in a hot sheltered position |
| Adelaide | Good in the warmest spot available |
| Melbourne, Canberra, Tasmania | Marginal. Frost tender - grow in a pot that shelters |
Neglect is the technique
This is genuinely counterintuitive and it is the main reason bougainvillea disappoints people. It flowers in response to stress, not to good treatment. A plant that is well watered and well fed produces vigorous green growth and very few bracts.
- Water sparingly once established. Letting it dry between waterings triggers flowering.
- Do not use high-nitrogen fertiliser, which pushes leaves at the expense of colour. Use a low-nitrogen, higher-potassium bloom formulation.
- Do not enrich the soil. Poor sandy soil produces better flowering than improved beds.
- Full sun, minimum six hours. Shade means no flowers at all.
- A pot suits it well, since restricted roots encourage flowering and make watering easier to control.
If your bougainvillea is lush and green with no colour, the answer is almost always less water and less nitrogen rather than more care.
The bracts are not the flowers
The colour comes from modified leaves called bracts. The actual flowers are the small white tubes at the centre of each group of three bracts. This matters because bract colour lasts far longer than a true flower would, which is why a bougainvillea holds its display for weeks.
Thorns and placement
Bougainvillea thorns are sharp, hooked and cause wounds that can become infected readily. Site plants well away from paths, play areas, pool surrounds and anywhere people brush past, and wear thick gloves, long sleeves and eye protection when pruning. In a family garden this is a genuine consideration rather than a formality.
Pruning and size
Prune hard after the main flowering flush. Bougainvillea flowers on new growth, so cutting back stimulates the wood that carries the next display. In tropical Queensland and Darwin it grows vigorously enough to need cutting several times a year, and an unmanaged plant will swallow a pergola or push into a roof.
Dwarf and compact cultivars are the sensible choice for a suburban garden or a pot, since they give the same colour without the scale.
Frequently asked questions
Why is my bougainvillea not flowering?
Nearly always insufficient sun, overwatering or high nitrogen feeding. Give it six plus hours of direct sun, let it dry between drinks and switch to a low nitrogen flower fertiliser.
Do bougainvilleas grow well in pots?
Exceptionally well. Restricted roots mimic the stress that triggers flowering, so potted plants often outbloom garden ones. Use a 40 cm plus pot with free draining mix.
How cold can bougainvillea tolerate?
They are happiest frost free and handle temperatures down to about 2°C. Established glabra varieties handle the odd light frost with minor tip burn, but hard or repeated frosts kill young plants, so pot culture suits cold districts.
How do I keep a bougainvillea small?
Grow a compact variety like Smarty Pants, keep it in a container and prune after every flush. Bougainvillea flowers on new wood, so regular cutting costs you nothing.
Ready to plant?
If you have a hot fence and a dislike of watering, bougainvillea was bred for you. Browse our climbers and groundcovers and the wider flowering plant range, grab a container from pots and planters, and check delivery to your postcode.
