Tree
Natural decay
Natural decay is the slow rotting of a stump left alone, as fungi and other organisms break the wood down over several years or longer.
Natural decay means doing nothing to the stump and letting it rot. Iowa State Extension calls this a cheap, easy, and safe option for stump removal, but it requires patience.
Speed depends on the wood and the site. Iowa State says that, depending on soil moisture, abundance of wood-decay fungi, and tree species, the process can take 10+ years. Illinois Extension reports that enhancing natural decay can accelerate degradation by up to 50 percent.
The stump stays a trip hazard and may sprout, and stump fungi such as mushrooms often show up. Home remedies like Epsom salt do not make it much faster. Compare with stump grinding, which takes hours. See stump grinding vs stump removal.