Shedding leaves helps trees and plants save energy and water. When the weather is too hot the plants needs its water and when it is too cold the plant needs its energy to stay warm. Special cells in the plant actually cut the leaves off like scissors! Before a plant cuts its leaves off it will suck up all the nutrients it can from the leaf first. Usually the first nutrient that is taken up is chlorophyll, the substance in plants that makes them green, and without chlorophyll the leaf will change color to red, orange or gold.