For extra shelter, you can surround the pots with bubble wrap or stuff straw between the containers to insulate against cold ...
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How To Prepare Hibiscus For Winter

Both hardy and tropical hibiscus plants can survive the winter with a little extra care before cool weather strikes.
Key Points Marigolds are tender annuals and are not frost-tolerant.You can protect marigolds from short cold snaps, but hard frosts will kill them.Saving seeds and preparing your garden are the best ...
After tending to your geraniums all summer, you can overwinter them instead of starting over next year. Here are three ways to overwinter geraniums for next year.