How to Kill Briar Bushes

Use a handsaw or chain saw to cut the briar bush down. Slice through the stump of the bush as close to the base, or where the stump meets the ground, as possible.

Cut off any roots extending from the ground with garden clippers. Dig around the area of the stump with a garden spade to help you unearth more of the briar bush’s roots. Dig up any roots exposed by your digging, and cut them off with your clippers.

Use a tiller, according to the manufacturer’s instructions, to till the soil above the briar bush’s roots. Press down on the tiller as you move it across the soil to allow it to till as deep into the soil as possible.

Turn off the tiller and set it aside. Shovel away all the loose soil from the tilled area with your spade. Then, till over the same patch of soil a second time to expose as much of the briar bush's root system as possible.

Boil water in a large pot. Pour the water into a large bowl designed to contain hot liquids. Pour the boiling water over the soil containing the briar bush’s roots until the ground is saturated. Repeat this procedure daily, cutting off any new roots or shoots that may appear with your clippers. Continue this procedure until the root system has been killed and no new growth appears.

If all else fails, use a herbicide with glyphosate, per the manufacturer's instructions, to kill the briar bush's root system. Spray the herbicide on the tilled area until the soil is saturated. The herbicide should poison and kill the root system. Take care to limit the herbicide spray to the tilled patch of soil, since the chemicals are toxic and exposure may kill other plants.