So, the question is, ‘why are evergreens able to keep their leaves while deciduous trees/shrubs lose theirs in the autumn?’ Due to the fact that evergreens do not become totally bare the myth is that they never lose their leaves. The truth is evergreens do lose their leaves… just not all at the same time (a bit like human hair). Evergreens keep their leaves for more that one growing season and some species for two to four seasons. Generally evergreens keep their leaves/needles for two to three years. Red needles at the tip of the stem and yellowing/browning interior leaves/needles are those preparing to drop. Every year they grow new leaves/needles and some of the old ones fall.

Though still engaging in photosynthesis, evergreens basically hibernate during the winter. They will use the leaves if necessary but they are in a greatly reduced activity state in the winter season. As I am certain you have noticed, evergreen leaves are generally thicker and harder than deciduous leaves and are often needlelike or scale like. This plus the shapes and strong waxy coating on evergreens makes them resistant to water loss, cold temperatures and keeps them from drying out in the winter. This explains why we find many more broadleaved (as opposed to needled) evergreens in warmer regions.