If more people knew about the princess flower, it would surely become one of the most popular plants on earth. To borrow from Will Rogers, I never met a man who met a princess flower he didn’t like.
Yet the princess flower (Tibouchina urvilleana) is still relatively
obscure. Its reputation grows daily, especially this time of year when it is available at many nurseries.
This plant, which is also and perhaps more fittingly called the glory bush, is made for the 1990s. People want perennials that flower for many months but don’t require lots of clean-up or maintenance.
The princess flower is reasonably fast-growing but, although it grows to 20 feet or more, is less dense and more manageable than a tree. It is often thought of as a large shrub. Yet at maturity, it could be considered a tree. This is important since, in an era of rain-forest destruction – scarcity of something creates more interest in it – people want to plant trees more than ever. Appropriately, its native land is northern Brazil, where the inhabitants for hundreds of years have called it ti-boo-shee-nuh.
The princess flower’s acidic soil preference hints at its tropical origins. In the tropics, almost daily rainfall has leached out the calcium, magnesium and sodium found in our own alkaline desert soils. To re-create a more tropical environment in the root zone, amend your backyard soil with peat moss or finished compost. The soil put back in the planting hole may contain up to 30 percent of these amendments.
While this plant needs a moister soil than drought-tolerant plants, watering can be minimized with several inches of mulch. Like the azalea, another plant that likes moist soil, the princess flower has leaf hairs that provide a margin of insulation from excessive heat. Where winters are somewhat cold – the princess flower can survive moderate frost – older leaves will turn orange and red before dropping off, although it will show some foliage throughout the year.
In the hot San Fernando, San Gabriel and Santa Clarita valleys, the princess flower grows well in partial or half-day sun, ideally under the shade of a tall sycamore, ash or pine tree. As you get nearer to the coast, it can take more direct sun. Placing it under a tree will provide an added measure of frost protection, as heat absorbed by trees and the ground below during the day radiates back and forth between them during the night, benefiting shrubs under the tree’s canopy.
This plant, with its dark shades, looks best growing against a white fence or wall. It grows well in containers, where white impatiens or alyssum are planted around its base for contrast. In colder areas, keeping it in a container makes sense.
Like many tall, woody perennials with long bloom periods, princess flowers benefit from having their feet (roots) in the shade and their heads (tops) in the sun. This is also true of hibiscus, gardenia and citrus, especially in areas such as Los Angeles, where the humidity is low throughout the year.
Such a microclimate is found between the side walls of two single story houses or low buildings. Almost any flowering tree, large flowering shrub or flowering vine will thrive in this spot, as long as it is exposed to at least four daily hours of bright light during the season(s) that its flower buds are normally produced.
Princess flowers produce their blooms exclusively on the ends of shoots. This means that, after flowering, these shoots should be pinched back to maintain a compact plant.
If leaves become chlorotic, don’t hesitate to fertilize with a preparation of Miracle-Gro, Peters 20-20-20, fish emulsion or seaweed extract.