Homes and businesses located near busy roads use shrubs to reduce traffic noise. The deeper the barrier, the greater the noise reduction. A 20-foot wide shrub buffer reduces decibel levels.
Evergreen shrubs provide year-round noise reduction. Cypress of the Arborvitae family has dense, dark-green foliage and can be planted close together to form a solid mass. American hollies are available in a variety of sizes and forms and can be mixed in a border.
Plant a sound-reduction shrub buffer as close to the source of the noise as possible. If you are using shrubs to reduce road noise, choose plants that tolerate road salts. Bayberry, a tough shrub, produces winter berries for the birds while standing up to poor soil and salt.
The United States Department of Agriculture recommends planting a mix of shrubs of varying heights. Trees and shrubs with ground level or weeping branches combined with low-growing evergreen shrubs will provide the maximum noise reduction.