How Often Should Hibiscus Be Watered?

Perennials

• The hardy hibiscus variety, Hibiscus moscheutos or rose mallow, is a perennial and can remain outside year-round. It is root hardy to climate zone 4. These plants die to the ground over winter, but new shoots emerge in spring. For the best flowers, keep the soil moist and feed every one to two weeks during the spring and summer. Water deeply and as often as necessary to keep the soil from drying out.

Winter Care for Perennials

• Rose mallow goes dormant in winter. Once the plants freeze, cut the stems back to a few inches in height. The plants need very little care while dormant, so discontinue watering and fertilizing until spring. Resume frequent watering and weekly to biweekly fertilizing in the spring. Hibiscus is one of the latest perennials to return, so be patient and do not assume the plant has died over the winter if it hasn't returned by May. It may surprise you in June.

Annuals

• Other hibiscus varieties such as Chinese Hibiscus (Hibiscus rosa-sinensis) and Red Leaf Hibiscus (Hibiscus acetosella) are tropical perennials that grow as annuals in northern climates. They need frequent watering and well-drained soil to produce prolific flowers. Plant less hardy hibiscus in early spring for late-spring and summer blooms. These plants will die after a day or two of freezing outdoor temperatures, or they can winter as houseplants. They do well in containers but take extra watering to keep the soil from drying out.

Houseplants

• Hibiscus plants do well as houseplants. Make sure the potting soil drains well and keep it moist. Fertilize every six weeks. Give hibiscus houseplants constant care year-round for year-round blooms. If you plan to keep a potted hibiscus plant outdoors in spring and summer then cut back on water and fertilizer when it is inside during the winter, and keep it in a cool place, between 50 and 60 degrees Fahrenheit. This will allow the plant to produce more blossoms in the spring and summer.