Pre commercial thinning

Pre-commercial thins are generally required in stands that are naturally regenerated, where thousands of seedlings per acre are established. The goal of a pre-commercial thin is to reduce stocking to 400 to 600 seedlings per acre. There is no merchantable material removed during this thinning; thus, it occurs at an expense. However, the removal of the excess seedlings will prevent tree stagnation and improve stand growth and development. To minimize cost, pre-commercial thinnings should be conducted before the stand is 4 years old. Mowing strips across the stand, leaving seedlings in 1- to 2-foot-wide rows, will quickly reduce the total number of seedlings. Row width is dependent upon seedling density.