Barberry bushes need to be trimmed periodically to manage their size and to stimulate new growth. Barberry bushes are often used as landscape ornamentals because they provide year-round color and bird-attracting berries. They make ideal hedges because they fill in quickly and grow densely. But if left to their own devices, they will quickly over-grow their adopted home. To avoid diving into a prickly mess, trim your barberry bushes annually to keep their size in check.
Lay a drop cloth around the base of your barberry bush to catch any trimmings that fall off of the plant.
Use a sharp, disinfected pair of hedge clippers to cut the outer edge's of the barberry bush's stems until the barberry is the desired shape. Don't worry about cutting too much. The barberry will soon grow in to fill out any gaps.
Carefully bag up all of the barberry trimmings and inspect the ground for any stems that may have been left behind. Even small pieces may take root and grow new barberry bushes.
Check the ground near your barberry bush for any sprouting barberry bushes in about one month. Dig these out as soon as you spot them.