The growth cycles of cinnamon trees are extraordinarily lengthy; it usually takes 15 to 20 years from the time of planting until any cinnamon can be harvested. Being a tropical plant, cinnamon needs a lot of moisture and extremely warm weather to survive. It takes two to three years for the full development of your cinnamon tree after planting. When the leaves become firm and the bark turns brown, it is time to harvest the plant.