After you cut down a shrub, you may still have to contend with its roots. Some shrub roots can send up new plants, called suckers, as a way of continuing the plant's existence. If you don't remove these suckers, they will grow into a new shrub. Additionally, the shrub roots may interfere with underground utility lines and prevent new plants from growing. The only way to get rid of shrub roots for good is to dig them out of the ground. This process is called grubbing.
Trace the path of the root by following suckers and seedlings back into the soil.
Dig up the soil around stumps, seedlings and suckers with a grubbing hoe or shovel to release as many roots as possible from the ground.
Grasp the root firmly with both hands and pull the root out of the ground.
Cut large sections of the root away using branch loppers or a root saw.