Home
Cape leadwort

Cape leadwort

Plumbago auriculata
A vigorous, scrambling, semi-climbing tender shrub that flowers almost without pause through the warm months, carrying broad clusters of soft sky-blue (or, in the white form, pure white) phlox-like flowers. Known as the Cape plumbago or Cape leadwort, it is native to South Africa (POWO, Kew) and is grown worldwide as an easy, long-flowering ornamental. The honest catch is its frost-tenderness: it is hardy only in USDA zones 9a-11, so in cold climates it is grown as a conservatory or large-container plant, or treated as a summer annual. Left to its own devices it climbs or sprawls 6 to 10 feet and needs support, or hard pruning, to keep its shape; the flower calyces are sticky and glandular and cling to clothing and animal fur (its own seed-dispersal trick), and it suckers. In return it is one of the best blue-flowered butterfly plants for a warm garden.
Climate fit: narrow (21/100)
Structure
Border
Container
Pollinator
Light
Full sun / Part shade
Water
Moderate water
Mature size
48-120" tall · 48" apart
Hardy in zones
9a-11
frosty to nearly frost-free winters
Native in Illinois
No
The phlox-like flowers are insect-pollinated and it is a genuine and well-loved butterfly plant — painted lady and red admiral butterflies work the blue blooms for nectar, and honey bees and other insects visit too.

Cold hardiness

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
Plotwright
USDA Zone 6b
-5°F to 0°F
Won't grow here
Zone 7a
Plotwright
0°F to 5°F
Won't grow here
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
Out of range today and still out of range in 2050.

Heat tolerance

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...

Plant this, not that

Better fit for this place
For Chicago, IL, these are replacement suggestions: similar plants with a stronger hardiness fit now and/or in 2050.
Physocarpus opulifolius
Common ninebark
A native North American deciduous shrub with exfoliating bark (hence "ninebark"), white-to-pink spring flower clusters, papery red seedpods, and reliable fall color. Colored-foliage cultivars (Diabolo, Coppertina, Summer Wine) extend the design palette. Adaptable + drought-tolerant once established.
Shrub
Full sun / Part shade
Moderate water
Zones 2a-8b
Climate: broad
Structure
Border
Pollinator
Better fit now and in 2050
Now: well-suited
2050: well-suited
Aronia melanocarpa
Black chokeberry
A drought-and-flood-tolerant native shrub of eastern North America with brilliant three-season interest — spring white-pink flowers, glossy black antioxidant-rich late-summer berries, and brilliant wine-red fall foliage — plus an extraordinarily wide cold-hardiness range (USDA 3a-8b). The berries are astringent fresh but the basis of a small but growing commercial industry (juices, wines, jams, supplements) for their exceptionally high anthocyanin content. Spreads by suckers; site where colony formation is welcome.
Shrub
Full sun / Part shade
Moderate water
Zones 3a-8b
Climate: broad
Border
Pollinator
Structure
Edible
Better fit now and in 2050
Now: well-suited
2050: well-suited
Calycanthus floridus
Carolina allspice (sweetshrub)
A native southeastern US deciduous shrub with deep-red strap-petaled fragrant flowers in late spring — the scent variously described as strawberry, banana, or wine, and reliably present only on cultivated cultivars with selected fragrance. Among the most distinctive native shrubs for woodland-edge and shaded mixed borders.
Shrub
Full sun / Part shade
Moderate water
Zones 4a-9b
Climate: broad
Pollinator
Structure
Border
Better fit now and in 2050
Now: well-suited
2050: well-suited
Clethra alnifolia
Summersweet (sweet pepperbush)
A native eastern North American deciduous shrub of swamps + damp thickets + sandy woods producing fragrant white-to-pink upright flower spikes in late summer when few other shrubs are blooming. Among the most fragrant native shrubs available; deer-resistant; tolerates wet feet + occasional flooding. Outstanding choice for rain gardens, shady borders, and low-maintenance native plantings.
Shrub
Full sun / Part shade
Moderate water
Zones 3a-9b
Climate: broad
Structure
Pollinator
Border
Better fit now and in 2050
Now: well-suited
2050: well-suited

Similar plants

Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Kolkwitzia amabilis
Beauty bush
A large, vigorous, fountain-shaped deciduous shrub that earns its common name in late spring, when its arching stems are smothered in masses of pale-pink, yellow-throated, bell-shaped flowers. Native to China, it is one of the great old-fashioned spring shrubs — spectacular in full bloom, much loved by bees, and offering peeling brown bark for quiet winter interest. It is also genuinely big: expect 6 to 10 feet tall and wide at maturity, so give it room rather than fighting its size with the shears. The form to seek out is the Award-winning "Pink Cloud", which carries a clearer, richer pink than the variable seed-grown species.
Shrub
Full sun / Part shade
Moderate water
Zones 4a-8b
Climate: narrow
Focal point
Structure
Border
Pollinator
Aronia melanocarpa
Black chokeberry
A drought-and-flood-tolerant native shrub of eastern North America with brilliant three-season interest — spring white-pink flowers, glossy black antioxidant-rich late-summer berries, and brilliant wine-red fall foliage — plus an extraordinarily wide cold-hardiness range (USDA 3a-8b). The berries are astringent fresh but the basis of a small but growing commercial industry (juices, wines, jams, supplements) for their exceptionally high anthocyanin content. Spreads by suckers; site where colony formation is welcome.
Shrub
Full sun / Part shade
Moderate water
Zones 3a-8b
Climate: broad
Border
Pollinator
Structure
Edible
Calycanthus floridus
Carolina allspice (sweetshrub)
A native southeastern US deciduous shrub with deep-red strap-petaled fragrant flowers in late spring — the scent variously described as strawberry, banana, or wine, and reliably present only on cultivated cultivars with selected fragrance. Among the most distinctive native shrubs for woodland-edge and shaded mixed borders.
Shrub
Full sun / Part shade
Moderate water
Zones 4a-9b
Climate: broad
Pollinator
Structure
Border
Physocarpus opulifolius
Common ninebark
A native North American deciduous shrub with exfoliating bark (hence "ninebark"), white-to-pink spring flower clusters, papery red seedpods, and reliable fall color. Colored-foliage cultivars (Diabolo, Coppertina, Summer Wine) extend the design palette. Adaptable + drought-tolerant once established.
Shrub
Full sun / Part shade
Moderate water
Zones 2a-8b
Climate: broad
Structure
Border
Pollinator
Chaenomeles speciosa
Flowering quince
A thorny, twiggy deciduous shrub from China (POWO, Kew), grown above all for flowers that open VERY EARLY — in late winter and early spring on bare twigs, before the leaves. The cup-shaped blooms are scarlet to orange (also pink or white in named forms) and, because they arrive when little else is open, they are a valuable nectar source for the first bees of the year and excellent for forcing as cut branches indoors. By autumn the shrub carries hard, fragrant, yellow-green quince-like fruits. It is hardy across USDA zones 4a-8b. Be honest about its temperament: it is thorny and can sucker, so it earns its place as an informal barrier or hedge rather than as a tidy specimen by a path.
Shrub
Full sun / Part shade
Moderate water
Zones 4a-8b
Climate: narrow
Border
Structure
Pollinator
Edible
Rubus odoratus
Flowering raspberry
A thornless native bramble grown for its flowers, not its fruit. Large, fragrant rose-purple to magenta blooms open over a long stretch of summer above big, soft, maple-like leaves on bristly (but prickle-free) canes. Native to the woodland edges and rocky slopes of eastern North America, it suckers into loose colonies 3-6 feet tall and is one of the few shade-tolerant, showy-flowered shrubs in the genus Rubus. The flat red aggregate fruit that follows is edible but dry and seedy — most gardeners grow this plant for the bloom and the unarmed, handsome foliage.
Shrub
Full sun / Part shade
Consistent moisture
Zones 3a-8b
Climate: moderate
Pollinator
Structure
Border

Sources & citations

Cite this page
For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.
Plotwright. (2026, May 17). Cape leadwort (Plumbago auriculata). Retrieved 2026, June 25, from https://plotwright.com/plants/plumbago-auriculata
Sources for every fact
Every fact on this page traces to a source. 18 fields cited - 18 source-backed.
Plants of the World Online (POWO)
Botanical research database
Backs 17 fields
Identity
Summary
Plant type
Light
Moisture
Hardiness
Heat zone
Size
Spacing
Habit
Design roles
Seasonal interest
Growth stages
Lifecycle
Regional guidance
Success tips
Designer notes
Wikimedia Commons
Photo
Backs 1 field
Image
RHS Find a Plant
Botanical research database
GBIF
Botanical research database
Wikipedia (ecoregion articles)
Botanical research database