Different hibiscus varieties offer glorious color choices for sunny garden areas. Care of hibiscus plants depends upon the variety, with hardy hibiscus plants and shrubs being able to withstand temperatures down to between 20 and 30 degrees below zero. Tropical hibiscus is more fragile, only tolerating temperatures down to about 20 degrees Fahrenheit. If you notice a hibiscus with severe damage, you may wonder if the hibiscus is dead. With careful examination, you might be able to tell if a hibiscus is dead -- although you may simply need to wait to see if the plant begins growing again.
Check the hibiscus plant for leaf buds. If you find leaf buds that have any green on the inside, these buds may still be viable. If you find leaf buds with only brown color on the inside, these leaf buds will not survive and indicate that at least this portion of the hibiscus plant is dead. Cut off these leaf buds with the pruning shears.
Scrape the outside layers of a stem of the hibiscus plant with the blade of the pruning shears or your fingernail to reveal the inside layers of the stem. If you find green layers inside the stem, this indicates the hibiscus plant is still alive. If you find only brown layers inside the stem, this indicates the hibiscus plant is dead.
Cut away up to one-half of the plant, removing damaged and dead branches from the hibiscus with the pruning shears. If you are not sure which branches are dead and which branches may be viable, scrape the stems with your fingernail again, looking for green inside the stem. If you do not find any green inside the stems, simply cut away about one-half of the plant to see if the roots can rejuvenate.
Repot the hibiscus, if possible. If the hibiscus grows in a container, repotting it may help rejuvenate it. Fill another container about halfway with fresh potting soil and carefully remove the hibiscus from its current container. Transfer the plant to the new container and add additional potting soil around the roots to fill the container. Water the soil to saturate it thoroughly and place the hibiscus in a location with moderate temperatures and light to see if it begins growing again.
Add compost around the hibiscus if the plant grows in the soil. Add about 2 to 3 inches of compost over the surface of the soil and scratch the compost into the soil with the hand rake. Water the soil generously to saturate it -- time will tell if the hibiscus is still alive.