Christmas tree shedding is a natural process that occurs when a Christmas tree begins to lose its needles. This is usually caused by a combination of factors such as dry air, lack of water, and the tree's age. Needles are the small, thin, pointed leaves of a coniferous tree, such as a pine or fir, which are shed as part of the tree's natural cycle. Shedding needles is a normal part of the life cycle of a Christmas tree and should not be cause for alarm.