When planting a sapling, it is often hard to imagine how large the full-grown tree and its root system will become. Many trees have surface root systems that will create problems in garden beds and turf as they get larger. They can push up concrete and pavers and look unsightly in the landscape. It is often difficult to remove these roots without damaging the tree. You may be better off simply removing the tree and replacing it with something more appropriate. In the event this is not possible, root removal is an extensive and time-consuming process with unknown consequences.
Put on a good thick pair of gloves to protect you from splinters and blisters. Add some eye protection to prevent flying chips getting in your eye. This is going to be a hard job and there is no sense adding injury to an already exhausting project. Root pruning should be done in late winter or early spring to minimize dehydration.
Dig a trench 1 foot from the drip line of the tree. The drip line is where the foliage ends in the perimeter of the tree canopy. This will be an investigative excavation to see how thick the root is and how far out it goes. Trees have four to five main roots. If you are cutting a main root, it may be time to seek help from an arborist as this may cause the tree to fail.
Unearth the point of the root where you will be cutting. Try not to damage any feeder roots as you are digging. Remove as much soil as you can from the cutting site, both on the sides and under the root. You should not cut the root within several feet of the trunk or you can cause the tree to lose balance. If the only option is a cut near the trunk you should call in professionals.
Use the handsaw, or in the case of huge roots, the chainsaw to make the cut. Ideally you should monitor trees as they are growing and then you can use pruners to take out offensive or future problem roots. You can also form barriers or move pipes where roots may start to grow.
Make the cut clean and straight. Do not remove more than 25 percent of the root as surface roots are important structures and removing more can severely harm the tree. Use the shovel to pry up the root or excavate more if necessary. For very large roots you may have to make several more cuts at the terminal end in order to make pieces small enough to remove manually.
Water the tree several times over the next two to three weeks. The biggest complication for the tree will be dehydration as it tries to accommodate to having less root to acquire water. Follow the tree care instructions for your variety carefully to rebuild a healthy system.