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Hi, Bill, The Tennessee mild

Hi, Bill, The Tennessee mild winter climate means that you may leave most hardy plum varieties outdoors over winter. We would, however, make sure the plant is sheltered from any wind. Keep it well watered.
      If you weren't in a mild-winter zone, we would recommend that you move your fruit trees indoors in winter, perhaps in an unheated garage.
If you aren't sure how hardy your tree is, we would advise that you call your Tennessee cooperative extension: https://utextension.tennessee.edu/pages/offices.aspx