Purchase healthy bare-root barberry plants at a nursery or order plants from an online source. If you will be planting a hedge, measure the length of the area where you plant to plant and purchase enough plants to fill the area, keeping plants 1 to 4 feet apart, depending on the species you have chosen.
Remove your plants from their nursery containers and gently loosen the roots, especially if they have become compacted or rootbound.
Dig planting holes from 1 to 4 feet apart in a straight line, depending on the species you have chosen, if you will be landscaping these plants as a hedge. You needn't add soil amendments such as compost because the barberry prefers soil that is unenriched. Make the holes wider than the nursery container, but make holes the same depth as the nursery container. Leave 4 to 5 feet of space between your planned hedge and other plants, buildings, sidewalks and other objects.
Place one barberry plant into each planting hole and then fill with the native soil you removed. Pat the soil down gently with your foot and then run a sprinkler over the area for at least 20 minutes.
Spread a 2- to 3-inch layer of any type of plant material as mulch over the planting area.