Hibiscus is a tropical flowering shrub that produces large, vibrantly colored blooms. The plant does not thrive in cold weather and frost can severely damage or kill portions of the shrub. Cutting the hibiscus plant back after frost will remove the dead plant matter and encourage the shrub to produce more, healthy shoots. Always use clean pruning shears when cutting back damaged plants.
Wait for all risk of frost to pass, even if it means leaving the damaged plant alone until spring. Frost-damaged branches will insulate the rest of the hibiscus against further damage from frost or cold temperatures.
Nick the damaged branches with a sharp knife in order to find out if the branches are dead. Start at the end of the branch and gently nick away a small piece of bark to expose the tissue underneath. If the tissue is brown or tan, that portion of the branch is dead. Continue moving down the branch toward the trunk until you find green tissue under the bark, which indicates live wood.
Move down the branch, starting at the spot where live tissue begins, to find the next bud or leaf node on the live tissue. Cut away the rest of the branch with pruning shears, making the cut 1/4 inch above the node on the live tissue.
Repeat the scratch test and cutting back on each branch of the hibiscus, whether it shows visible frost damage or not. Not all frost damage is visible immediately after cold weather passes.