Yucca louisianensis is another of the great southeastern US native plants that few people either know or grow. Yucca louisianensis is essentially a narrow, long-leaf version of the more common Yucca filamentosa. The leaf edge of Yucca louisianensis often upturns slightly, giving the appearance of a white edge. For us, Yucca louisianensis makes a 3' tall x 4' wide rosette of narrow green leaves. When mature, the rosette is topped with an 8' tall flower spike of white bells. Although we are conservative on our zoning, I'd be surprised if Yucca louisianensis doesn't turn out to be as winter hardy as Yucca filamentosa. Yucca louisiana 'Granted Wish' is from our 2003 accession from Grant Parish, Louisiana.