What does plant hardiness refer to?

Plant hardiness refers to a plant's ability to endure and thrive in adverse growing conditions, which can include extreme temperatures, drought, frost, or other environmental stresses. This concept is crucial for gardeners, landscapers, and agriculturalists as it determines which plants can survive in specific climates or conditions.

The assessment of plant hardiness typically involves understanding a plant's resilience to cold, heat, and other challenging environments. For instance, a plant classified as hardy in a particular USDA hardiness zone can survive the minimum temperatures of that zone, indicating its robustness against cold weather.

The other options pertain to different aspects of plant biology: sunlight exposure pertains to light requirements, growth rates relate to how quickly a plant develops under ideal conditions, and disease resistance is about the plant's ability to fend off pathogens. While these factors can contribute to a plant's overall health and success, they are not synonymous with hardiness.