DIY
Stump killer
Stump killer is a chemical product sold to speed stump decay or stop regrowth. Iowa State Extension says these products are often fertilizer, such as potassium or sodium nitrates.
Iowa State Extension says commercial stump removal formulas can be used as directed on the label. It adds that these products tend to be a form of fertilizer, often potassium or sodium nitrates, so regular fertilizers can work just as well. Some products also contain a herbicide, such as triclopyr, glyphosate or imazapyr, to help prevent resprouting.
Iowa State says to use them as directed to prevent damage to nearby plants. The stump still has to rot afterward, which the same source says can take 10 or more years by natural decay. Read the label for each product. The guide on whether stump killer works compares the options.