Q&A for How to Kill Tree Roots

For young trees, you can cut them down and dig out the root system. If the roots are too developed to dig out, you can cut down any new growth until it stops coming up.

Any of the standard methods described here should work. Black walnut roots are toxic to other plants, and can continue to damage many other plants for months or years after the tree is killed. Digging up every root is nearly impossible, so consider planting tolerant species, or growing affected species in containers.

If the tree is close enough to grow against the fence, there is no way to keep them apart without permanently removing one or the other. Killing roots that close to the tree will likely cause the whole tree to die. If the tree is encroaching from another property, that property's owner is usually legally responsible for addressing the issue.

If you only want to kill the root, dig in an adjacent location and sever the root at a position before it enters the plot. For a more permanent solution, kill the whole tree by applying herbicide to the stump or exposed trunk.

Try to move the bricks and as much of the stump as you can, and then use hedge clippers.

Cut the roots and install a root barrier as described above. Roots rarely cause significant damage to foundations, but if it seems like large roots have penetrated, hire someone to check for issues.

Yes, salt will kill the grass and other vegetation in the area. Use an herbicide that doesn't "flash back" to other plants instead, such as glysophate.

If you carefully drill small holes randomly around the tree at different heights, then fill the holes with herbicide, it will look like a natural tree death. This method works when a homeowner association won't let you remove a tree you don't like.

Cut ithe tree down in January. When spring arrives, the sap will flow up frtom the roots and the tree will die. Some poplar roots are fairly near the surface and they can travel a long way fast so do your best to remove those roots that have travelled a long distance or a new tree may spring up somewhere else. My poplar roots here are a yellow color and very flexible so some roots may pull up in a long strip. Drill big holes in the stumpand put epson salt crystals in the holes which will dry out the stump and make it easier to dig out or help it decompose naturally.