While stump milling takes care of the visible remains of the tree, the roots of the old tree are still scattered underground, sometimes 4, 8, or 12 feet beyond where the stump was. After grinding, these roots will naturally decompose, but it's a lengthy process. It can take more than 10 years for roots to fully decompose. It can accelerate the decay of excess roots by allowing shoots that grow from the stump to reach approximately 1 foot in height before cutting them off the stump.
This causes roots to deplete their resources quickly so they start to break down faster. In most cases, wait four to five years for the root system to deteriorate before planting another tree in the soil that was beneath the foliage of the old tree. A faster and more permanent way to treat tree stumps is to treat the leaves on the shoots with a herbicide. The poison from the herbicide will be absorbed by the leaves and will travel to the roots.
This process takes about a year to completely kill the roots. Painting the very stump of the freshly cut tree with herbicide prevents new shoots from growing and also helps kill roots. Another option is to drill some holes in the trunk to allow the herbicide to penetrate inside and be absorbed by the roots more quickly. These roots can remain active for long periods of time, causing the stump to produce new shoots with green foliage for several years after cutting down the tree.
Once a tree is cut down, its roots stop growing within a few weeks and then die; the stump eventually rots. Push the stump back and forth to loosen the roots and continue to cut and tear off the roots until you can remove the root ball from the soil. Repeat this treatment several times over the course of a few months and the rock salt will eventually kill tree roots. The stump and roots of the felled tree also produce root shoots and saplings to try to keep the tree growing.
It can take two to seven years for the constant removal of sprouts from stumps to completely deplete the nutrients stored in the roots. If left untouched, a tree's stump and roots will begin to rot and, over time, become a home for pests, fungi and other organisms. Copper sulfate is a natural herbicide and will kill small tree roots that invade sewer pipes. Cut them with a pruner just below ground level or, preferably, at the point where they meet the roots or stump, removing the parts of the stump that are sprouting.
Until the nutrients stored in the roots of the tree are exhausted, the stump will strongly resist putrefaction. However, once the work of cutting down the tree is finished, you may wonder what happens to the roots of the trees when the tree is cut down. Soak the leaves thoroughly in the white vinegar and any sprouts that emerge from the roots of the trees will eventually destroy the roots of the trees. Conversely, some tree species aggressively sprout from the roots, even after cutting down the tree and shredding the stump.
Also, do not remove roots that are close to the trunk or that are fused with it, as they are fundamental to the structure of the tree.