Hibiscus Sabdariffa Survival In Cold Weather

Q: I planted four hibiscus sabdariffa plants last year. They got much larger
than I expected but I propped them up with stakes and twine. They are now
either dead or dormant. Do I pull them up? 

A: Hibiscus sabdariffa, aka roselle or Red Zinger hibiscus, is not cold-hardy in
Atlanta. Our cold weather has probably given the stems a big whack but they
MIGHT sprout again from the roots. Cut them back to a foot tall and cover
each one with a cardboard box. Put a rock on the box to hold it down until
things warm up in late March. Uncover the plants and see what happens.