Instead of abandoning land after logging, silviculture seeks to regrow the forest as soon as possible. These plantations are typically grown as an even-aged monoculture for timber production. Plantations are also sometimes known as "man-made forests" or "tree farms", though this latter term also refers to specialist tree nurseries which produce the seedling trees used to create plantations. More generally, a plantation is forest land where trees are grown for commercial use, most often in a planted forest, but may also be in a naturally regenerated forest. In the United States, the term "Tree Farm" is a trademark of the American Tree Farm System, a third party verification system for certifying sustainable forestry. The American Tree Farm System dates back to 1941 as a program to improve forestry practices on privately owned forestlands. The term tree farm is also sometimes used to describe the sale of live trees for landscaping.