What is a hardiness zone? And where am I in it? A hardiness zone is a geographically-defined zone in which a specific category of plant life is capable of growing, as defined by temperature hardiness, or ability to withstand the minimum temperatures of the zone. It is crucial you know which zone you live in if you are trying to maintain a healthy garden. North Carolina rests in Hardiness Zone 7, which is defined by a long growing season and mild winters. Conditions perfect for gardening! Most plants can be grown in this hardiness zone, aside from tropical varieties.