In Jack's Zone 8 garden this pink justicia is killed to the ground by freezes each winter but reappears by mid-spring and usually begins flowering in July and continues until frost. Download a large version (800x600) of this image.
This tropical evergreen perennial or small shrub is a shade lover and a perfect choice for bringing dazzling color to the darker areas of your garden. The large coarse leaves are about 8 inches long by 2 inches wide. They're a rich green and depending on the variety they are oblong and pointed on the end. The smaller varieties grow in mounds about 2 feet high while others are more shrublike and grow up to 7 ft in height and 6 ft wide. In summer the plant covers itself with large showy spikes of flowers in shades from white, pink, red, orange, purple and yellow. The flowers are tubes, flared at the mouth and curving outward from the center of the spike on which the flowers are arranged.
I like to use white justicia in the shady parts of the garden where it is happy to grow and brighten its neighborhood with beautiful snowy white flower spikes.
The justicias that you are likely to encounter in nurseries and catalogs are hybrids. Many are the results of crossing J. carnea with other species member of the genus. Justicia carnea is native to South America and the many other species are distributed in tropical and subtropical areas in both hemispheres.
Justicias thrive in rich, well drained garden soils but are tolerant. Fertilize three times a year in spring, summer and early fall. Cut back lanky stems after blooming to maintain a neat shape. Light: Justicias are shade lovers. Moisture: Average water. Hardiness: USDA Zones 9 - 11. Tender to frost. Justicias are root hardy in Zone 8 where they are invariably frozen to the ground every winter but grow back in the Spring. Propagation: Justicia cuttings are very easy to root. Just cut 8-12 in pieces of stem, remove all but the top 2 leaves and dust the root end of the stem with rooting hormone powder. Cover the stem 1-2 inches deep in potting soil and keep moist.
I saw this showy yellow justicia at Orlando's Leu Gardens many years ago - wish I had some, it was labeled Justicia spp.
Justicias have been popular container and greenhouse plants since the early nineteenth century when they were raised in Victorian conservatories. Use them in pots and containers indoors or in shady entryways, porches and patios. The smaller varieties can be used as a colorful groundcover in shady areas. Larger varieties make great background plants and can be used in mixed hedges. Because they produce lots of flowers throughout the heat of summer, justicia is becoming popular in northern gardens where it is grown as an annual or lifted into pots and wintered indoors.
Justicia can't be beat for adding bright patches of vibrant color to shady areas. They are readily available from nurseries and discount stores in warm areas of the country (and becoming more available in cooler zones due to distribution by the big garden and home center chain stores). They are inexpensive, easy to grow and easy to propagate. If you have a shady spot that needs some interest and color, I highly recommend this plant.