Tree planting is when you put a new tree in the ground so it can grow and make the environment better. It can help suck up pollution from the air, provide shade and homes for animals, beautify an area, and even produce food for us to eat. Put simply, it means taking a seed or a small tree, either from a nursery or from the wild, and planting it in the ground where it will be cared for and nurtured until it grows big and healthy.