Best plants for noise-buffer screens

There is a significant gap between what people expect from plant noise buffers and what plants can actually achieve. Per Penn State Extension, a dense, 100-foot wide planting of trees can reduce traffic noise by 6–10 decibels -- a noticeable but modest reduction. By comparison, a 6-foot solid.

There is a significant gap between what people expect from plant noise buffers and what plants can actually achieve. Per Penn State Extension, a dense, 100-foot wide planting of trees can reduce traffic noise by 6–10 decibels — a noticeable but modest reduction. By comparison, a 6-foot solid masonry wall achieves 15–20 dB reduction. Plants are not substitutes for acoustic barriers in high-noise environments.

What plants do provide: psychological noise reduction (the perception of noise decreases when natural elements are visible), white noise masking (rustling foliage and moving leaves partially mask distant sounds), and visual screening that removes the sight of the noise source, which reduces the stress response to noise per University of Illinois research.

Design principles for noise-buffer plantings

Per Penn State Extension:

• Depth matters more than height. A 50-foot wide planting provides more reduction than a single tall row.
• Evergreen outer rows are critical. Deciduous trees lose their effectiveness in winter when traffic noise is typically loudest (less ambient competition).
• Dense branching to the ground. A tree with bare lower branches allows sound to pass underneath. Choose species with dense low branching or combine with understory shrubs.
• Living walls and berms. A planted berm (even 2–4 feet high) increases noise reduction by positioning the plantings above the noise source line-of-sight.

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