What is the purpose of a plant hardiness zone map in horticulture?

• A. To plan fertilizer rates
• B. To evaluate soil texture
• C. To measure irrigation efficiency
• D. To select plants suited to winter minimum temperatures and climate tolerance

Answer: (D)

Matching plant selection to winter cold tolerance is what the plant hardiness zone map helps you do. This map shows the typical minimum winter temperatures for different regions, so you can choose plants that are rated to survive those cold conditions. By selecting species that can withstand the cold in your area, you reduce the risk of winter damage or dieback. It’s not about fertilizer, soil texture, or irrigation efficiency—those factors come from other tools and practices. Keep in mind microclimates, wind exposure, snow cover, and soil drainage, which can make a slight difference from the broad zone rating, but the map provides a practical starting point for hardy, perennial plant choices.