What plant characteristic helps in reducing water usage in gardens?

Drought resistance is the plant characteristic that significantly contributes to reducing water usage in gardens. Plants that exhibit drought resistance possess various adaptations that allow them to survive with less water. These adaptations may include deep root systems that access moisture from deeper soil layers, thicker leaves that reduce water loss through evaporation, and overall morphological changes that help the plant withstand prolonged dry conditions.

In contrast, the other characteristics listed do not directly impact water usage. Fertility resistance relates to a plant's ability to thrive in poor soil conditions, which does not pertain to water conservation. Cold tolerance helps plants survive in low temperatures but has little relevance to their ability to manage water. Pest resilience pertains to a plant's ability to withstand pest damage, which again doesn't affect its water needs or usage. Therefore, drought resistance is the primary factor that enables efficient water use in gardening.