What do plant hardiness zones indicate?

Plant hardiness zones primarily indicate the climatic conditions of an area, specifically the temperature ranges that plants can tolerate. These zones are determined based on the average annual minimum winter temperature, which helps gardeners and landscapers understand which plants are likely to survive in their local environment.

By knowing a plant hardiness zone, individuals can make informed decisions when selecting plants for their gardens or landscapes, ensuring that the chosen species are suitable for the local climate. This is crucial for promoting healthy plant growth and reducing the likelihood of plant stress or failure due to unsuitable temperatures.

The other options relate to factors that influence plant health but do not directly define what hardiness zones measure. Soil types, pest resistance, and water requirements are important considerations in horticulture, but they do not correlate directly to the specific temperature-related indicators that hardiness zones represent.