I don't have exact numbers on how many Christmas trees can be planted per acre, but it depends on the species and variety of the tree, as well as the type of soil and climate conditions in the area. In general, it's recommended that you plant at least 1,000 trees per acre, but you may be able to plant more if you choose a more compact variety or plant the trees closer together. It's important to do your research and consult with a local expert before deciding on how many trees to plant.