Answer: Purple fountain grass is winter hardy in zones 9 through 11. You are in zone 7 so treat it as an annual in your garden. Some of the ornamental grasses hardy in zone 7 include:
Deschampsia caespitosa (Tufted Hairgrass), Eragrostis spectabilis (Purple Love Grass), Festuca gigantea (Giant Fescue), Festuca glauca (Blue Fescue), Festuca mairei (Maire's Fescue), Helictotrichon sempervirens (Blue Oat Grass), Hystrix patula (Bottlebrush Grass), Miscanthus sinensis 'Central Park' (Maiden Grass),
Nassella tenuissima (Mexican Feather Grass), Panicum virgatum (Switch Grass),
Pennisetum alopecuroides 'Moudry' (Black Seeded Fountain Grass) and Saccharum ravennae (Ravenna Grass).
Q&A Library Searching Tips