Kill a tree stump by using Epsom salt, rock salt, controlled burning or forced darkness. Burning is by far the fastest method, while Epsom salt can take up to three months of time before producing results.
Epsom salt produces healthy effects in trees when provided in small doses. To kill a tree stump with Epsom salt, it is necessary to expose the stump's roots to a large amount of Epsom salt solution. Mix pure Epsom salt with water, drill 12 10-inch deep wide holes into the wood, pour the solution into the holes and cover the tree with a tarp for three months.
Rock salt dries out tree stumps by absorbing water in the soil. The crystals must be combined with water to form a solution and then poured into holes drilled into the stump just like Epsom salt. Additionally, a 2-inch layer of rock salt should be added around the base of the stump and hot water poured on the salt. Cover the top of the stump with mulch and leave it for six weeks.
Controlled burning is not legal in all areas, and can be dangerous. The safest way to burn a stump is by drilling holes into it, pouring kerosene into the holes and igniting the stump.
To kill a tree stump with darkness, cut the stump at its roots and cover it with a black trash bag. Add weight to the top of the bag, completely depriving the stump of sunlight, and let it sit for eight weeks.