Answer: There are several different kinds of hibiscus. If it is the hardy woody shrub also called Rose of Sharon (Hibiscus syriacus) you can trim it back now if you need to control the size, you would also cut it back in spring as needed to remove any winter killed branches. Dead wood will be dry and brittle and dull gray or brown. Live wood will be supple and have green inside the bark. Trim it back until you reach live wood. This shrub leafs out very late in the spring so be patient with it.
If you have one of the perennial hibiscus flowers, it normally dies back to the ground each winter. The dead stems can be trimmed off after they have frozen in late fall or else in early spring. You might want to mark the location of the plant when you trim it back, it comes up late in the spring and this helps you avoid accidently stepping on it or planting on top of it.
If you plantede a tropical hibiscus or Hibiscus rosa sinensis, it would not have survived your Ohio winter and sadly, would be dead.
I hope this helps.
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