Introduction
This sprawling, evergreen shrub or small ornamental tree ranges from 10 to 15 feet (20 feet with proper training) in height. It can be trimmed to any size and still put on a vivid, year-long flower display. The dark green, velvety, four to six-inch-long leaves have several prominent longitudinal veins instead of the usual one, and are often edged in red. Large, royal purple blossoms, flaring open to five inches, are held on terminal panicles above the foliage, creating a spectacular sight when in full bloom. Some flowers are open throughout the year but they are especially plentiful from May to January. Princess flower is ideal for the mixed shrubbery border or used in small groupings to compound the impact of bloom-time.
General Information
Scientific name: Tibouchina urvilleana
Pronunciation: tib-oo-KYE-nuh er-vill-ee-AY-nuh
Common name(s): princess flower
Family: Melastomataceae
USDA hardiness zones: 9B through 11 (Figure 2)
Origin: Brazil
UF/IFAS Invasive Assessment Status: invasive and not recommended except for "specified and limited" use approved by the UF/IFAS Invasive Plant Working Group
Uses: hedge; deck or patio; screen; specimen; container or planter; espalier; trained as a standard
Description
Height: 10 to 15 feet
Spread: 10 to 15 feet
Crown uniformity: irregular
Crown shape: vase, round
Crown density: dense
Growth rate: moderate
Texture: coarse
Foliage
Leaf arrangement: opposite/subopposite
Leaf type: simple
Leaf margin: entire, ciliate
Leaf shape: lanceolate, ovate
Leaf venation: bowed, parallel
Leaf type and persistence: evergreen, broadleaf evergreen
Leaf blade length: 4 to 6 inches
Leaf color: dark green on top, paler green underneath
Fall color: no color change
Fall characteristic: not showy
Flower
Flower color: purple
Flower characteristics: very showy; emerges on terminal panicles
Flowering: primarily spring through winter, but also year-round
Fruit
Fruit shape: round capsule
Fruit length: less than .5 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/branches: branches droop; not showy; typically multi-trunked; no thorns
Bark: brown and smooth to lightly roughed
Pruning requirement: needed for strong structure
Breakage: susceptible to breakage
Current year twig color: green
Current year twig thickness: medium
Wood specific gravity: unknown
Culture
Light requirement: full sun
Soil tolerances: clay; sand; loam; acidic; well-drained
Drought tolerance: high
Aerosol salt tolerance: none
Other
Roots: not a problem
Winter interest: no
Outstanding tree: no
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: resistant to pests/diseases
Use and Management
Princess flower requires full sun for best flowering and will thrive on any well-drained soil when regularly watered. Its growth habit is somewhat weedy, requiring training and pruning to develop and maintain it as a tree. It can be trained as a standard or espaliered against a west-facing wall receiving at least five hours of full sun. It can also be trained on a trellis or arbor as a vine. Pinching new growth helps increase branching and will enhance the flower display.
Tibouchina granulosa grows larger (15 to 20 feet tall and wide) and is easier to train into a tree.
Propagation is by cuttings.
Pests
Some of its pests are scales and nematodes.
Diseases
Mushroom root rot in soil which is kept too wet.
References
Koeser, A. K., Hasing, G., Friedman, M. H., and Irving, R. B. 2015. Trees: North & Central Florida. Gainesville: University of Florida Institute of Food and Agricultural Sciences.
Koeser, A.K., Friedman, M.H., Hasing, G., Finley, H., Schelb, J. 2017. Trees: South Florida and the Keys. Gainesville: University of Florida Institute of Food and Agricultural Sciences.