What is a plant hardiness zone?

• A. A region's climate classification based on winter minimum temperatures used to predict plant survival
• B. A region's rainfall classification
• C. A region's soil type classification
• D. A region's pest risk classification

Answer: (A)

Plant hardiness zones measure how cold an area gets in winter, using the average minimum temperatures to predict which plants can survive there. This classification, such as the USDA map, assigns a zone number to a region based on how low winter temperatures typically drop. A lower number indicates colder winters, so plants must tolerate harsher cold; a higher number indicates milder winters. This focus on winter cold tolerance helps gardeners choose species and varieties that have a good chance of surviving year after year. It’s different from classifications of rainfall, soil type, or pest risk, which relate to moisture, soil properties, and pests rather than winter survival. Remember that microclimates, wind, snow cover, and soil drainage can influence actual survival, so zones serve as practical guidelines rather than guarantees.