When developing or starting a teak (Tectona grandis) plantation, deciding upon the correct terrain and site are fundamental to a successful operation. The ideal soil for growing teak trees is a tropical flat terrain that drains naturally, receives an average yearly amount of 2.000 millimeters in rain (preferably seasonal), and is rich in calcium. After planting, a well-managed teak plantation will yield between 100 and 200 cubic meters of teak (growth) per hectare annually by the tenth year, which then increases to between 200 and 500 cubic meters per hectare annually by year thirty. Later on, by age 50, each individual teak tree is expected to reach an approximate height of 30 meters and up to 65 centimeters in diameter at breast height (DBH). In order to grow properly, teak trees require good amounts of sunlight and space, which means that the recommended amount of trees per hectare is between 1.200 and 1.600 to allow appropriate spacing. Additionally, in order to ensure that the trees receive a proper amount of sunlight through their early development, during the first three years, the teak trees should be grown without any other plant species around them and weeding should be done on a weekly basis.
Rotation and Thinning in Teak Plantations
Key elements for the proper development of the teak trees are well-timed thinning and pruning. Thinning refers to when some of the underperforming trees in the plantation are cut and sold prematurely, thus allowing the best trees to continue developing fully with more space and soil nutrients. Meanwhile, pruning refers to the cutting of the side branches off the main trunk of the trees while they are growing in order to ensure straight and high-quality logs. The first round of thinning in a plantation should take place by hectares, when the 100 largest trees of each hectare have reached a height of 9 to 9.5 meters, which usually occurs five years after planting. Consequently, the second round of thinning should occur when the 100 largest trees of the hectare section have reached 17 meters, which is approximately ten years after planting. The key with the early years of development is making sure that the tree crowns do not become too large or expand too far horizontally, since this will lead to a large amount of unnecessary growth in the crown as well as invade the space of neighboring trees.
The harvest rotations for teak plantations go anywhere from 20 to 80 years, depending on the schedule developed by the managers or the financial expectations of the investors. However, the average harvesting period for teak plantations is of 40 years. In this regard, the determination to cut and sell the teak logs at a certain time can also be influenced by favorable market openings. Normally, after age 25, the growth of teak trees slows down in terms of height and width. Nevertheless, during these later years, the growth of dark heartwood accelerates within the tree trunk, which eventually means more returns at the time of final harvest.