How To Care For Hardy Hibiscus In Winter. These are tropical plants and dont survive exposure to freezing temperatures. If you live in a location where the temperatures fall to below freezing during the winter season youll need to protect your hardy hibiscus to ensure they survive.
First off if you live in an area where temperatures stay below 50F 10C for more than brief periods youll need to bring your hibiscus indoors to save it over winter. Hibiscuses need well-draining soil to thrive and poor-draining soil will cause root rot. Remove the mulch in spring when youre sure theres no danger of hard freezes.
In areas with wintertime temperatures below freezing make sure plants have 3 to 4 inches of mulch to protect the roots over the winter.
Deadhead hardy hibiscus in the fall. Nitrogen is what encourages growth. But a trait the two varieties certainly share are the bright beautiful tropical looking flowers. Fertilize hibiscus with a high potassium fertilizer in spring and prune branches in spring before new growth appears.