To kill a tree stump, cut it low and paint or spray a herbicide labeled for cut stumps, such as glyphosate or triclopyr, onto the ring of pale wood just inside the bark within minutes of the cut. A dead stump stops sprouting, but it is still a stump, so the wood then has to rot, be ground out or be dug up.
First, does your stump need killing at all?
Many do not. Penn State Extension notes that conifers rarely sprout from a stump, so a pine cut last month is already dead wood and chemicals add nothing. Hardwoods are different. Red maple, tulip poplar, oak, sweetgum and Bradford pear will often throw a ring of shoots the next spring, and that is the stump telling you it is alive. Ask what you are trying to stop. If it is sprouting while the stump sits for years, a herbicide makes sense. If the stump is about to be ground below grade, skip it, because grinding turns the sprouting part to chips anyway.
Why the outer ring is the only part that matters
The living part of a cut stump is a thin band. Just inside the bark sit the cambium and the sapwood, the paler wood that carried water up from the roots. The dark center is heartwood, and it was already dead. Penn State Extension says to treat the sapwood on stumps four inches and wider. Alabama Extension narrows it to roughly the outer two inches of the cut face. On stems under about four inches, wet the whole face. Brush off sawdust and soil before you start, because both soak up the product before the wood can take it in.
Timing: minutes after the cut, late summer or fall
Water-based products, which covers most glyphosate and triclopyr amine mixes, have to go on right after the saw. A University of Arizona bulletin notes that most labels want the product on within five minutes of the cut, while the wood is still open. Oil-based triclopyr ester is more forgiving: Alabama Extension says it can go on within a few weeks, sprayed over the top and down the sides. Season matters as much. In late summer and fall a tree sends sugars down into its roots and carries the herbicide with them. Early spring is the weak window, and a stump that weeps sap after cutting is pushing upward. Skip it if rain is due within four to six hours.
Picking a product and reading the label
Look for the words cut stump on the label, then check the active ingredient and its percentage. Alabama Extension found ready-to-use glyphosate under 20 percent and triclopyr amine under 8 percent do not work consistently on stumps, and that the stronger products should not be watered down. A trigger bottle of lawn weed killer mixed for leaves is the wrong tool. Steer clear of soil-active ingredients in a yard. Iowa State Extension warns picloram, sold as Tordon, leaches and persists in soil, and Alabama Extension says imazapyr and aminocyclopyrachlor can be taken up by the roots of plants you want to keep. A spray dye shows which stumps are done.
The trees next door can share the roots
This is the trap people do not see coming. Neighbors of one kind, say two maples side by side, can grow into each other below ground, and the University of Arizona bulletin warns that root grafts like that let herbicide pass from one tree into the next. The same bulletin says plainly that shoots rising from a tree you mean to keep must never be sprayed or painted. So if your stump was one of a row of the same tree, or shoots are coming up near a healthy neighbor of the same kind, stop and ask before you treat anything. N.C. Cooperative Extension and Clemson Extension county offices answer exactly this sort of question.
An old stump that keeps sprouting
Once a cut is weeks old the face has sealed, and a water-based product brushed on it does little. You have two ways back in. Cut the stump again, lower, and treat the fresh ring at once. Or let the shoots grow some leaf, cut them, and treat their cut ends. Iowa State Extension says to keep cutting and treating new sprouts until they stop, and Penn State Extension warns the first round may weaken roots without killing them. Pouring herbicide into drilled holes in an old stump does not help it rot, Iowa State adds, and can harm nearby plants. Tree-of-heaven is its own problem: Penn State says cut-stump treatment works poorly on it, so ask your Extension office.
Gear, and keeping it out of the wrong places
Wear eye protection and chemical-resistant gloves. Alabama Extension specifically warns against leather gloves and leather boots, which soak up many herbicides and hold them against your skin. Long sleeves, long pants and closed shoes are the minimum on most labels, and the label is the final word on what else you need. Mix only what one job needs, since stored pesticides do not keep forever. Near a creek, ditch or pond, use only a product labeled for use around water. Keep children and pets off the treated stump until it has dried, and store the jug locked away.
A dead stump is still a stump
Herbicide stops the green. It does nothing for the wood, which will sit there for years. Left alone, Iowa State Extension puts natural rot at ten years or more, depending on the tree, the moisture and the fungi present. You can speed that up with drilled holes and nitrogen, covered in how to rot a tree stump. Or have it ground. A stump ground four to eight inches below grade loses the collar where sprouts start, so for most yard stumps stump grinding handles the shoots and the wood in one visit, with no chemical step at all.
Common Questions
What kills tree stumps and roots quickly?
A herbicide labeled for cut stumps, such as glyphosate or triclopyr, applied to the outer ring of a fresh cut within minutes. Late summer and fall work better than spring because the tree is moving sugars down to its roots. It still takes weeks to show, and the wood remains. If you want the stump gone fast, grinding is quicker than any chemical.
Does bleach or rock salt kill a tree stump?
Neither is sold or labeled as a stump treatment, so there is no tested rate or method. Rock salt carries a real cost: Wisconsin Extension explains that sodium building up in soil creates a drought-like condition for roots and breaks down soil structure, which hurts the lawn and beds around the stump far longer than the stump itself.
Can I kill a stump without hurting the trees around it?
Usually, if you treat only the cut ring, avoid soil-active products such as picloram and imazapyr, and keep spray off bark and leaves nearby. The exception is a neighbor of the same species, which may share roots through grafts. In that case ask your county Extension office first, or grind the stump instead and use no chemical.
What to Do Next
If you want the stump gone rather than just dead, grinding below grade deals with the sprouts and the wood together. A photo of the stump, one of the route to it and the name of your town are enough for a real number at (828) 574-4474. If shoots are the main worry, read how to stop stump sprouts.