Grades: K-5; Subject Areas: Science. (2008) In autumn, Nick is busy raking leaves. He briefly explains the process of photosynthesis and why deciduous trees need to drop their leaves in the fall. The leaves contain lots of nutrients, however, so that's why they can be used in compost. Provides several examples of leaf shapes and sizes, linking the green color to chlorophyl. Nick is really impressed that leaves are the only living things that can make food from sunlight. Two young friends gather a wide variety of leaves, press them, and scan them on a computer in order to make appealing greeting cards.