Which of the following is not a requirement of the plant schedule for exterior water use reduction?

The correct answer pertains to the requirements for a plant schedule focused on reducing exterior water use. An effective plant schedule should emphasize aspects that contribute to water conservation and sustainability in landscaping.

While annual water demand is an important consideration in overall water management, it is not specifically a requirement for the plant schedule itself. The plant schedule is primarily concerned with choosing appropriate plant species that thrive in the local climate, implementing water-efficient irrigation systems, and outlining maintenance practices that ensure sustainable landscape management.

Selecting plant species that are adapted to the local environment helps reduce the need for excessive watering, making option B relevant. Water-efficient irrigation systems are essential for minimizing water usage, thus making option C important. Additionally, maintenance practices for sustainability support the long-term health of the landscape and its water efficiency, which aligns with option D's significance.

Therefore, while annual water demand plays a role in overall water planning, it does not directly relate to the specific requirements of the plant schedule aimed at reducing outdoor water use.