Tree removal can be a dangerous, expensive and messy job. An unfortunate consequence of some tree removals is a large stump and root system that remains even after the tree is cut and hauled away. Although the majority of the tree is gone, the roots may still be capable to sprout new growth. Kill the tree roots immediately after a tree removal to prevent the chance of new growth and speed up the decomposition of the roots and stump.
Drill holes in the roots at a 20-degree angle with an electric drill and 4 cm (1 1/2 inch) drill bit. Space each hole 10 cm (4 inches) apart. According to master gardener Ed Hume, each hole must be between 20 cm and 25 cm (8 and 10 inches) deep. If you need to kill an entire stump, drill holes in the top of the stump as well.
Fill the holes in the roots and stump with salt. Salt in any form can be used, whether it be standard table salt or rock salt.
Cover the holes with at least 2.5 cm (1 inch) of soil and 5 cm (2 inches) of mulch. Water the mulch until thoroughly moist.
Add more water to the mulched area each day to ensure the roots stay moist. The high concentration of salt and moist environment will encourage nutrition depletion and decomposition.
The salt may make it difficult for plant life to grow in the area for the next several years.