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Paper flower

Habit (mature) - Kızıl / Wikimedia Commons - CC BY-SA 4.0

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Paper flower

Bougainvillea glabra

A vigorous evergreen woody climber from Brazil — called primavera or buganvilia in its homeland — grown across the warm world for its long-lasting, brilliant papery bracts in magenta, purple, white, or pink. The vivid color is not from petals: it comes from those papery BRACTS (modified leaves), which surround the small, tubular, cream-colored true flowers tucked at their centers. POWO (Kew) and Flora e Funga do Brasil both record Bougainvillea glabra as native to Brazil. Left to climb it hauls itself up walls, fences, and pergolas to 10-30 feet, but kept pruned it makes a dense, mounding shrub; it is armed with sharp thorns and flowers hardest when grown lean, hot, and a little dry in blazing full sun. It is frost-tender and hardy in the ground only in USDA zones 9b-11b; everywhere colder it is grown as a greenhouse, conservatory, or container plant and overwintered indoors.

Climate fit: narrow (27/100)

Focal point

Structure

Light

Full sun

Water

Low water

Mature size

120-360" tall · 120" apart

Hardy in zones

9b-11b

frosty to nearly frost-free winters

Native in Illinois

Grown strictly as an ornamental — it is not food, and no part is eaten.

°C

°F

Cold hardiness

Future

2050

2100

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.

Now

Zone 6b

USDA

Published baseline for this location from 1991-2020.

Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer

Won't grow here

2050

Zone 7a

Plotwright

Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).

Won't grow here

In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.

Out of range today and still out of range in 2050.

Heat tolerance

Future

2050

2100

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.

Loading AHS heat-zone data for this location...

Where this plant fits

Suitable across 25 ecoregions — 18 climate-resilient through 2070 · 7 newly possible by 2070. Best matches first.

Arizona Mountains forests

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Atlantic coastal pine barrens

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California coastal sage and chaparral

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Central Pacific Northwest coastal forests

Eastern Australian temperate forests

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Fynbos shrubland

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Klamath-Siskiyou forests

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Mississippi lowland forests

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What it needs

Conditions

Light

Full sun

Water

Low water

Spacing

120"

Habit

Vigorous evergreen thorny woody climber from Brazil — frost-tender, drought-tolerant, and grown for its papery bracts (kept as a mounding shrub when pruned); armed with sharp thorns and an irritant sap, ornamental only

Care tips

•

Grow it lean and a little dry in blazing full sun: let the soil dry between waterings and go easy on nitrogen, since overwatering and rich feeding give you leaves instead of the papery bracts you want.

•

Treat zone 9b as the cold edge — it is frost-tender, so in colder regions grow it in a container, keep it in full sun, and move it to a bright, frost-free spot before the first freeze.

•

Prune right after each flush of color, not before: bougainvillea blooms on new growth, so cutting back after flowering shapes the plant and triggers the next wave of bracts.

Lifecycle

Planting

Where hardy (USDA zones 9b-11b), plant in spring in full sun in light, fast-draining soil against a strong support — a sturdy trellis, pergola, wall, or fence — since the mature climber is heavy and vigorous. In colder regions grow it in a container of free-draining mix that can be moved to a bright, frost-free spot for winter. Space plants about 120 inches (10 feet) apart. Handle with gloves: the stems are armed with sharp thorns and the sap can irritate skin.

Transplanting

Bougainvillea resents root disturbance and its roots break easily, so move it as little as possible: plant or pot it up gently in warm weather, keeping the rootball intact, and avoid teasing the roots apart. Pot-grown plants are best slid into a slightly larger container rather than bare-rooted.

Early growth

Train the long, thorny new growth onto its support and let the soil dry between waterings — it flowers far better grown lean and a little dry than lush and wet. Go easy on nitrogen, which drives leafy growth instead of bracts. Wear gloves and long sleeves while tying it in, since the thorns are sharp and the sap can irritate skin.

Maturity

In frost-free climates it matures into a large, evergreen thorny climber that blooms in repeated flushes most of the year, heaviest in warm, dry, sunny spells. It flowers on new growth, so prune right after a flush to shape it and trigger the next; mild water stress and lean soil keep the bracts coming. In cold regions a mature container plant is overwintered indoors and pruned hard.

Propagation

Propagated from semi-hardwood or hardwood stem cuttings taken in summer, rooted in warm, moist, free-draining medium; named color forms are grown from cuttings to come true. It is grown vegetatively rather than from seed in cultivation.