The United States Department of Agriculture (USDA) Plant Hardiness Zone Map divides North America into 13 zones based on average annual minimum winter temperatures. This map provides a standard by which gardeners and growers can determine which plants are most likely to thrive at a location. For instance, a plant rated for zones 6-8 is expected to survive winter conditions in those designated areas. A state-specific adaptation of this map indicates the hardiness zones prevalent within its boundaries, aiding residents in making informed planting decisions.
Understanding regional hardiness is crucial for successful agriculture and horticulture. Selecting plants appropriate for a specific zone minimizes the risk of winter damage, such as frostbite and death. Historically, this knowledge was gained through trial and error. However, the modern mapping system offers a scientifically-backed framework, reducing waste and increasing the likelihood of successful plant growth. This supports economic efficiency for commercial growers and enhances the aesthetic value of home gardens.