How to Naturally Kill a Shrub

Prune the shrub as close to the ground as possible. After using hedge trimmers, you may have enough access to the stump to use an axe or saw.

Hammer a copper spike vertically into the center of the trunk. Such spikes are normally used to hammer down copper roofing and can be purchased at a hardware store. Autumn and winter are the best times to do this, because the shrub's nutrients (and the copper) will then be pulled into the root system. The copper spike can help disintegrate the roots, which is important to avoid a revival of new shrub shoots the following spring.

Cover the stump with an opaque tarp to deprive it of sunlight after you've driven the spike in.

Pour bleach into the stump around the spike and the roots. Do this over several days. Alternatively, pour salt into the open stump. This is not as good for the soil as the above steps, and it is certainly optional. However, the more approaches you try, the better.