Deciduous describes trees and plants that lose all their leaves every autumn and grow fresh ones in spring. Maple trees, oak trees, and birch trees are all deciduous. In fall, their leaves turn brilliant shades of red, orange, and yellow before dropping to the ground, leaving bare branches through winter.

The opposite of deciduous is evergreen. Pine trees and most other conifers stay green year-round, keeping their needles through every season. If you walk through a forest in January, the bare trees are deciduous while the green ones are evergreens.

Why do deciduous trees lose their leaves? In cold climates, keeping leaves alive through winter would waste precious energy and water. By dropping their leaves, deciduous trees protect themselves during harsh months when there's less sunlight for photosynthesis. When spring arrives with warmer temperatures and longer days, deciduous trees sprout fresh leaves and start growing again.

Scientists also use deciduous to describe anything that falls off seasonally, like the antlers that deer shed every year.