What can I put on tree roots to stop them from growing?

What can I put on tree roots to stop them from growing? To stop tree roots from growing, especially after cutting tree or to prevent regrowth, you can put systemic herbicide that kills roots. Most effective is herbicide containing triclopyr or glyphosate, such as Tordon RTU with picloram, Garlon 4 Ultra with triclopyr, or Roundup concentrate with glyphosate, painted or sprayed on freshly cut stump and exposed roots, especially on cambium layer, herbicide translocates to root system and kills it preventing sprouting. For sewer line roots, put copper sulfate crystals or foaming root killer like RootX with dichlobenil into pipe, kills roots inside pipe without killing whole tree. Homemade options include putting rock salt or Epsom salt in drilled holes in stump, salt dehydrates and kills roots over months, or high concentration vinegar and salt solution. You can also put root barrier fabric or metal sheet in soil to physically block root spread. For prevention, put thick mulch over area to discourage surface root growth. So put triclopyr herbicide on stump for permanent stop, copper sulfate or RootX for sewer roots, or salt for slower natural kill.