Overview of the Princess Flower:
A native of Brazil, the princess flower (Tibouchina urvilleana) is a glorious addition to tropical and sub-tropical gardens. Its large purple flowers and soft hairy leaves add interest and a burst of color to any landscape. It can also can be used as an indoor container plant in cooler regions if full light and warmth is provided. Though it is usually a shrub here in the United States, it sometimes becomes large enough to form a small ornamental tree.
This shrub is a recipient of the Award of Garden Merit given out by the Royal Horticultural Society.
The botanical name used for this species is Tibouchina urvilleana. Sometimes it is listed as Tibouchina semidecandra. It is included within the Melastomataceae family.
You may see this named as the princess flower, glory bush, pleroma, purple glory bush or lasiandra. Princess flower may also be used for other species in the genus.
Preferred USDA Hardiness Zones:
Zones 9-11 are best for this shrub. It can be grown in Zone 8, but winter frost will cause it to die back until warmer temperatures return.
Size & Shape of Princess Flower:
The princess Flower is 10-20' tall at its mature size and can be pruned to be more compact. It is round or vase-shaped.
Plant in full sun, though it can tolerate some afternoon shade, especially in the hottest zones.
The leaves are 2-6” in length and 1-1.5” wide, covered in soft hair and often tipped with red around the edges.
The flowers are 3-5” wide and a deep, vibrant purple. Princess flower can produce blooms year-round, especially if it is deadheaded to encourage the formation of more flower buds.
The fruit is a small brown capsule that is under .5" long
Use the princess flower as a specimen plant or for borders and foundations.
The large vibrant purple flowers and soft hairy leaves work well in sensory gardens.
Grow in rich fertile soil that is well draining. Soil is best if it is slightly acidic. You can make your soil a little more acidic if needed. Fertilize after each time it blooms.
If you live in a cooler USDA zone, you could plant the princess flower in a container to be brought in each winter. You can also have it be a houseplant with enough warmth and light.
Propagate using softwood cuttings.
Protect against frost and strong winds.
Prune to maintain a rounded shape. Pinch new growth to encourage branch formation. Prune lightly after blooming.
This shrub can be trained to form a standard if you prefer it to have a tree shape.
Pests & Diseases:
Occasionally scale, nematodes, and geranium budworm may attack. Mushroom root-rot can occur if over-watered.