What Kind of Weather Conditions Are Ideal for a Hibiscus?

Climate

• Most hibiscus plants are perennials. They grow and bloom year after year when conditions are right and if they are cared for properly. The plants are tropical in origin, so most of them thrive in warmer climates. In general, hibiscus plants grow best in U.S. Department of Agriculture plant hardiness zones 5 through 10, although this can vary widely depending on the species. For example, the popular Chinese hibiscus (Hibiscus rosa-sinensis) grow best in USDA zones 9 through 11, while the equally popular Rose of Sharon (Hibiscus syriacus) can tolerate the cooler temperatures in USDA zones 5 through 9.

Temperatures

• Warm temperatures are a must if hibiscus plants are to develop buds properly, according to the University of Minnesota Extension service. A late spring cold snap may cause bud drop. Or, it may prevent the buds from forming properly. They thrive when temperatures are consistently warm between 65 and 75 degrees Fahrenheit, and when low temperatures do not drop below 55 degrees. This is true for plants grown indoors as well. Dramatic fluctuations in temperature may also cause the plant to drop buds or flowers.

Weather

• Hibiscus plants in general love sunlight. They need plenty of sun exposure to bloom. If you bring a plant from the indoors to an outdoor location, however, it will need to gradually adjust to being in direct sunlight. Place it on the porch for a few days, then in the filtered light under a shade tree, and finally in full sunlight. Rain is a plus because it keeps the soil moist -- and hibiscus plants thrive in cool, moist soil -- but too much cloud cover will reduce blooming. The more sun, the better and more numerous the blooms.

Other Conditions

• Although sunny weather and warm temperatures are important, other environmental factors are just as important for optimum growth of hibiscus. The plants thrive in soil that is rich in organic matter, and although they prefer moist soil, it needs to be well-draining. Overly wet soil may lead to the development of fungal diseases in some species. A few species and cultivars can tolerate occasional flooding, however.