Pros & Cons of a Hibiscus Plant

Tropical Versus Hardy

• Tropical hibiscus varieties, such as Chinese hibiscus (Hibiscus rosa-sinensis) hardy in USDA zones 9 through 11, must have warm conditions year round to flower. In fact, they die back significantly if exposed to nighttime temperatures below 55 degrees Fahrenheit. In contrast, hardy hibiscus cultivars, like giant rose mallow (Hibiscus grandiflorus), hardy in USDA zones 7 to 10, withstand cooler temperatures and produce larger flowers than tropical species. When you select a hibiscus for your yard, verify that you can cultivate it outdoors without harm. Plant it in a container if it is tender so you can move it indoors, if necessary.

Disease

• Hibiscus is vulnerable to several fungal and bacterial pathogens, from root rots to leaf spots. These shrubs often grow taller and wider than 10 feet, making them thirsty plants in the landscape. While it requires consistent watering, hibiscus needs a well-drained soil site. Wet soil conditions lead to root and crown rots. Rot quickly moves up the trunk and limbs to affect the entire hibiscus; foliage and flower dieback are common. Use a drip irrigation system to seep water into the soil at an accurate rate to reduce wet conditions and save water at the same time. A drip system also keeps water droplets off of leaves to prevent leaf spots and mold growth.

Pests

• Garden pests as varied as mealybugs and nematodes flock to hibiscus plants. One major reason for pest infestation is the ample foliage. As the shrub or tree grows, foliage covers most of the limbs, making it easy for pests to hide unnoticed. For example, soft scales populate darkened bark areas while aphids feed on leaves hidden in the shadows. When cultivating hibiscus, inspect your plant often for any pest populations. Small populations are easier to remove without chemical controls, but major infestations cause significant stress to the hibiscus.

Flower Size and Longevity

• If you want spectacular flower sizes, choose a hardy hibiscus like giant rose mallow. Its 10-inch wide blossoms dwarf the 4-inch wide Chinese hibiscus flower. However, each hibiscus has a different blossoming schedule. For example, giant rose mallow is a night-bloomer, whereas Chinese hibiscus flowers during the day. Some flowers last one or two days, whereas other varieties hold their blossoms for several weeks. Select a variety that reflects your landscape's needs, especially if you want showy flowers that last long.