Perennial Hibiscus is easy to grow

The tropical look is so hot right now-all the more reason to plant a Perennial Hibiscus. Perennial Hibiscus is a rather large family of plants-about 220 species in all.

They are members of the malvaceae or Mallow family. Who would have thought that a cousin to okra and cotton could be so glamorous? Actually these plants are herbaceous perennials, meaning their tops die down to the ground each winter, but new shoots will come back into lush growth when soils warm in the spring. Hibiscus moschuetos is the most commonly found perennial hibiscus in garden centers. Although native to the Carolina forests, most perennial hibiscus plants are rated a USDA zone 4 for winter hardiness and down to a warm zone 9 for summer heat tolerance.

They are typically July-August bloomers although a few bloom later than this. If grown in good rich soil, this plant will quickly turn into a 4-6-foot tall bush every spring. The flowers will also be amazingly large at 6 inches across. They should be pruned to the ground in the fall and they will regrow each spring. Don't give up on them, since they are one of the last perennials to emerge in the spring.

Most seed catalogues carry the "Southern Belle" perennial Hibiscus, which will delight you with huge 6-inch blossoms in late summer once the plant has reached 4 feet to

6 feet. It tolerates full sun or partial shade and likes moist, rich soil. Plants should be spaced 24-36 inches apart. This plant requires consistently moist soil; do not let it dry out between waterings. Soil pH requirements are 6.1 to 6.5 (mildly acidic). New plants can be propagated by dividing the rootball, from herbaceous stem cuttings, from seed (sow indoors before the last frost in the spring or direct sow in the garden after the last frost). If you would like to collect seeds in the fall, allow the pods to dry on the plant. Then break open and collect the seeds.

Other varieties include "Cotton Candy" with pink and white flowers, "Satan" (blood red), "Radiation" (deep pink), and "Crimson Wonder" (crimson). "Kopper King" (has coppery-red foliage with massive white flowers containing a red eye) is the most popular variety and is the result of more than 20 years of work by the Fleming brothers. These three plant breeders took painstaking efforts to develop beautiful flowers, as well as ornamental foliage. "Lord Baltimore" is another perennial hibiscus, which is a rather large bushy perennial plant with massive bright red flowers, and "Fantasia," a compact form, only growing to 3 feet tall, but having massive rose-pink flowers.

If you purchase perennial Hibiscus moschuetos, be extremely careful with transplanting. It resents having its roots moved and can turn from a large, healthy plant into a basket case with careless moving or even weeding that disturbs its roots.

Many people have asked, "How do I tell if I have a Hardy Hibiscus or a Tropical Hibiscus? Unfortunately, garden center, nurseries and home improvement centers lump all hibiscus together. If a hibiscus has glossy, deep green leaves, 3-6" flowers of red, pink, orange, yellow, double or single flowers, it is probably a TROPICAL hibiscus. While many common garden varieties have the 3-6" blooms, many of the hybrid varieties of tropical hibiscus can have blooms around 10" in diameter under ideal conditions.

Another way to check is if the flowers are salmon, peach, orange or yellow, or double flowered, then you probably have a TROPICAL hibiscus. Hardy hibiscus do not come in these colors or in doubles. Many tropical hibiscus flowers have more than one color in a bloom either in bands or as spots.

If your hibiscus has dull medium green, heart-shaped leaves, dinner plate sized white, pink or red flowers with HUGE, bomb-shaped buds (2-4" in length), it is a perennial, hardy hibiscus, which needs very little care outdoors over the winter.

If you have a tropical hibiscus, remember it is a TROPICAL. It will not tolerate more than a night or two of light freezes. Even one hard freeze (below 25 degrees) could kill the plant. The plants are native to sunny, warm and usually humid tropical places. They detest cold, rainy weather and cold, wet soil. They will not reliably survive outdoors north of zone 9. In all other areas, it may be a good idea to bring them indoors BEFORE temps regularly drop below 40-45 degrees F at night to avoid any damage.

Feel free to prune your hibiscus to fit the space where it will live indoors. It is not important where you make the cuts, as long as they are made cleanly with a sharp pruner. Just remember that you will not see much (if ANY) new growth from this pruning. The hibiscus growth slows down considerably during the late summer/fall and winter. This is also a good reason NOT to repot in the fall. The hibiscus will not generate new roots easily at this time and will probably suffer from root rot before it gets re-established. Never place a tropical hibiscus in anything smaller than a 10-inch pot.

Potting soils are not recommended. Use light soilless mixes such as PRO-MIX and Sunshine Mix, which are available at most nurseries / garden centers. These soilless mixtures consist of perlite, vermiculite and peat moss, with some bark. Jungle Mix, a professional seed starting mix, available from some home / garden centers, also produces good results.

Remember that tropical hibiscus does best with very good drainage. Occasional use of a 20-20-20 water soluble fertilizer is appropriate. During the winter indoors, most hibiscus plants may develop a problem with aphids or white fly. One of the non-chemical ways to help with this is give your hibiscus a shower. Cover the top of the pot snugly with aluminum foil or heavy plastic (to keep the soil from washing out and making a mess, and also to prevent waterlogging the roots), and make sure that you completely seal off the pot around the stem. Then just stick the plant, pot and all, in the shower, and turn on a low to moderate spray directly on the leaves. Use lukewarm to comfortably warm (NOT HOT!) water. Do this for about 5-10 minutes being sure to get the undersides of the leaves, as well. Do this once or twice during the winter. It will not eliminate the pests but will certainly control them, and your hibiscus will thank you.

So, whether you grow the hardy, perennial hibiscus or the tropical hibiscus, you will be delighted with their beautiful tropical-looking flowers, but remember each type requires radically different care to thrive.

If you have questions regarding this article or any other lawn and garden question, please call the Woodbury County Extension Master Gardener Answer Line at (712) 276-2157.