In addition to their amazing heat tolerance and outstanding summer performance, we grow tropical plants for a variety of reasons. Some, such as hibiscus, ixora, canna, angel trumpet, bird-of-paradise and butterfly ginger, are grown for their beautiful, and often-fragrant, flowers. Others, such as peacock ginger, caladium, elephant ears and copper leaf plant, are grown for their attractive, colorful foliage.
The best tropicals are those that reliably survive winters where you garden. Despite their tropical origins, many are hardy throughout the state if given some winter protection.
Gardeners who are working with shady areas will find a gold mine of shade-tolerant plants among the gingers. In their natural habitats, most gingers grow under the canopies of trees in filtered light, although some grow in the open at the edge of water and in sunnier conditions.
Generally, gingers will do best where they receive direct sun for about two to four hours a day and should not be planted in hot, sunny, dry locations. Shell ginger and some types of Curcuma and Costus will, however, grow in full sun.
Many different gingers can fill a variety of gardening needs. Low-growing gingers, like peacock ginger and smaller species of Curcuma or Globba, make great ground covers or clumps at the front of shady borders. Medium-sized gingers three to six feet tall include species and varieties of Curcuma, Hedychium and Costus, while the shell ginger grows 10 to 12 feet tall. These larger gingers are excellent choices for accent, screens or at the back of a border.
No other summer-flowering shrub surpasses the tropical hibiscus for glossy, dark green foliage and nonstop flowers in shades and blends of pink, yellow, orange, white, lavender or scarlet. The long blooming season runs from late spring through November or later.
The tropical hibiscus thrives in sunny locations and looks great in beds or containers. It is one of the more tender tropicals and will not reliably survive temperatures below the mid-20s. Still, they are readily available and not too expensive. And it’s easy enough to replace any lost to winter freezes. If you grow them in containers, you can move them inside on cold winter nights.
We grow a number of species of Clerodendrum for their beautiful, fragrant flowers and, in some cases, ornamental fruit. They may freeze back during especially cold winters but reliably return from their roots. Perhaps the most well-known is the cashmere bouquet. Effortlessly easy to grow in part shade to shade, cashmere bouquet produces four- to five-foot-tall stalks with large clusters of small, fragrant, mauve flowers. But it spreads rapidly.
Many of the clerodendrums produce stems that run underground and produce plants some distance from the original plant. But none is quite as bad as cashmere bouquet. If you’re aware of this habit and promptly remove sprouts from areas where you don’t want them, the problem is solved. But if you’re the type of gardener who is not inclined to keep a careful eye out and remove them as necessary, you probably shouldn’t plant those that spread rapidly.
Other great clerodendrums include harlequin glory bower. This large-shrub-to-small-tree looks as tropical as the rest, but in fact, it is quite hardy. It drops its leaves in winter but does not freeze back. In June/July, it produces large clusters of very fragrant white flowers that last until August. Then amazing turquoise fruit continues the display. It spreads rapidly.
Another clerodendrum that produces attractive fruit after its long, tubular white flowers is C. indicum. Although not common, I’ve seen this tall (to 12 feet) clerodendrum growing in south, central and northern Louisiana. It spreads slowly.
As a group, clerodendrums are very attractive to butterflies and hummingbirds. One is even called butterfly shrub because of the exquisite blue, butterfly-shaped flowers it produces. It does not spread.
Including tropicals in the landscape has many rewards, but you do need to be aware of the hardiness of the plants you choose and be prepared to protect them when and if necessary.
For more information, contact Dr. Chris Robichaux, county agent/area horticulturist, St. Martin/Iberia Parishes, at 332-2181 or 369-4440.