The tree peony--which is actually a shrub, not a tree--is the national flower of China. They live very long lives and grow quite slowly, eventually reaching three to five feet in height. The tree peony has larger flowers that bloom in more colors than its herbaceous cousin, some with double blooms.
A bit of a dilemma exists for the peony gardener, in that the plant blooms easiest in full sun, yet the blooms last longer if the tree peony is planted in partial shade. For residents of USDA zone 9, with the long growing season and mild winter, there are a number of varieties of tree peony to choose from, most with lovely, exotic names.
"Necklace with Precious Pearls"
A rather pricey variety, this tree peony blooms with red buds that usually open into double, soft pink flowers. Sometimes you will get a surprise, however, and the bloom will remain magenta with pink splotches or pink with splashes of red. A compact variety, it will reach three feet tall at maturity, which is generally five years. Plant your Necklace with Precious Pearls in October in Zone 9.
"Green Dragon Lying on a Chinese Ink Stone"
If you are looking for a richer, darker-colored flower, consider the Green Dragon Lying on a Chinese Ink Stone. This peony tree blooms in deep, almost-black purple flowers. The foliage is of interest as well, a light green, sometimes tipped with purple. This variety will look wonderful as the lone planting in a sunny area of a zone 9 garden.
"Number One Scholar's Red"
Beautiful magenta flowers with a lovely scent bloom in the spring on Number One Scholar's Red peony tree. This is one peony you may choose to plant in an area that will give it a bit of afternoon shade, or dappled sunlight in order to preserve the flower's rich coloring. Remove dead flowers throughout the season. In the summer heat in some Zone 9, areas the tree peony will need extra attention paid to the moisture content of the soil. Keep it moist, but not soggy.