Evergreens are trees that grow back year after year. They are not planted in the ground like Christmas trees are. Evergreens are usually taller and have a more rounded shape than Christmas trees. They also grow to be more dense and have better color retention. Christmas trees, on the other hand, can be found in many different shapes and sizes. They can also be planted in the ground like evergreens but do not typically live for as long as evergreens do.