Briar patches are created from the overgrowth of certain types of plants, many of which are berry plants such as raspberries and blackberries. Briars in general are not pleasant things to deal with because the vines have sharp thorns that can cut and rip not just clothing but skin as well. These plants are not typically satisfactory in lawns and gardens. There are several ways to get rid of them, but only one method proves to be permanent.
Put on heavy-duty work gloves and clothing that covers the entire body. It is a good idea to layer your clothing to further prevent the thorns from catching your skin.
Dig up all the briars and place them into the wheelbarrow. When you're done, the ground should look like freshly tilled ground. Try to get as much of the roots as possible.
Put the plants into a fire pit and douse them with gasoline or lighter fluid. Light the fire immediately, especially if using gasoline. Allowing the gasoline to sit for any amount of time encourages the movement of the fumes, which also ignite, so in order to prevent an explosion of any magnitude, light the fire immediately.
Go back to the ground where you removed the briar plants. Spray or disperse weed killer as directed by the label. Follow repeat application suggestions on the label for optimum results.
Animals that eat the berries excrete the seeds, and from there the seeds may root and flourish, so a thorough inspection of your yard every summer for briar patches should be done to keep the briars at bay.
Exercise extreme caution when using any ignition fluid for fires. They can cause explosions and be extremely dangerous causing burns and possible death.