The number of Christmas trees grown per acre can vary depending on the species and the desired size and quality of the trees. Generally, an acre of land can produce anywhere from 200 to 1,000 trees, with the majority of farms aiming for a density of around 500 trees per acre. However, some farms may opt for a lower density to allow for more space between the trees and promote healthy growth. The size and quality of the trees can also affect the yield, with larger, more valuable trees requiring more space and resources.