Using Trees and Shrubs to Reduce Noise

Noise from vehicles and others sources can reduce one’s enjoyment of being outdoors.  Dense, tree buffers can reduce noise to levels that allow normal outdoor activities to occur.  For instance, a 100-foot wide planted buffer will reduce noise by 5 to 8 decibels (dBA). If one uses a barrier in the buffer such as a landform can significantly increase buffer effectiveness (10 to 15 dBA reduction per 100-foot wide buffer with 12-foot high landform).          

The table and guidelines below provide general design considerations when implementing a buffer for noise control. 

Key Design Considerations

• Locate buffer close to the noise source while providing an appropriate setback for accidents and drifting snow.

• Evergreen species will offer year-around noise control.

• Create a dense buffer with trees and shrubs to prevent gaps.

• Select plants appropriate for the site conditions.

• Select plants tolerant of air pollution and de-icing methods.

• Natural buffers will be less effective than planted buffers because they are usually less dense.

• Consider topography and use existing landforms as noise barriers where possible.

Estimating Setback Distance from Noise Control Buffers

A setback distance from the noise control buffer may be necessary to achieve the desired levels of noise reduction along a high speed road. The charts below can be used to estimate this setback distance.  For example: An outdoor recreational site near a highway needs to be located to meet the desired noise levels of 60 to 65 dBA. If 100-ft wide tree/shrub buffer is used, the site needs to be 100 to 200 feet behind the buffer. The site can be located immediately behind the buffer if a 12-ft high landform is incorporated into the buffer. 

This post is an excerpt from Conservation Buffers: Design Guidelines for Buffers, Corridors, and Greenways.  Check out the Guide to learn more about designing buffers to improve air water quality, protect soil, enhance habitat, enhance economic productivity, provide recreation opportunities, and beautify the landscape.

9 Comments

  1. All of my houses have had berms and trees built up to reduce traffic noise and it worked every time. Once I stacked logs on top of the berm for additional noise reduction. It looked great and really cut down the noise. The one I’m working on now is the largest yet in preparation for a highway expansion. I’m using brush, leaves, garden waste, used cat litter, rocks, logs, to build up the hill. All the organic matter will compost and feed the trees for years to come. I will add soil to firm it up and finish it smooth.

  2. You assume that one has a huge yard. In most cities, the yards are small and houses are crammed closely together. This article on noise reduction with trees is only applicable to those in the country, in which case, they probably don’t live near any noise producing roads or neighbors. So it is useless.

  3. Thanks for the article. I have been considering putting in some type of buffer. My issue is a power line (poles) easement running along the roadside. I have been considering a meadow, but would I be better served by putting up a berm and planting native trees/shrubs. Is there a model to show how this affects road noise ?

  4. This morning I had an appointment for a checkup with my dentist, and given that I’m an arborist we always talk about his tree planting efforts.

    Here in southeastern Nebraska many Scots & Austrian pine trees are dying due to pine wilt. Just a few weeks ago one of his prized Scots pine turned brown and died over the score of a few weeks. Meanwhile, my dentist has been busy planting spruce & fir trees to make up for the losses. Just like a dentist…he is working to fill in the cavities in his windbreak/buffer. Lonnie knows that the road adjacent to his property will be widened in the next 10 years. By planting a diverse selection of conifers now he will have noise control in place in time for this construction. This will make the property more livable for his family, and more attractive to potential buyers should they decide to sell and move to a new home.

    This is an excellent example of good planning. Even on a small property it is critical to visualize the impact your tree planting will have 20, 30 40 years out. By planting the right trees in the right place one can expect successful outcomes like this one.

  5. Chris…you might check with your local utility company and see what size of trees & shrubs can be planted along the easement. While I don’t know of model showing the noise reduction benefits of planting hedgerows on berms there are many other reasons to create a buffer for your property.

    Some of the benefits include enhanced visual interest, wildlife habitat, dust & odor filter, privacy & screening, and management of drifting snow. To see examples please take a look at this publication.

    USDA National Agroforestry Center
    Conservation Buffers: Design Guidelines for Buffers, Corridors, and Greenways

    http://www.unl.edu/nac/bufferguidelines/

  6. yes, i recently brouth a house,and i need help on how to buffer the noise reduction around my home,and privacy and screening.i live in the cite and my house sits on a busy corner, i love trees and i need help on growing,and planting them and understanding them.i need help,the trees that are in my yard looks like to me are dying,i don’t know who do i call? i know nothing about trees,but love them and want to help save the trees.please help if you can with any information that you can.thank you!

  7. John…please share the state and county that you live in. With this basic information I can put you in touch with great local resources to help with your tree planting efforts.

  8. We recently to move to a place facing Highway 44 in Oklahoma City. We have 1.6 acres land. Please give me suggestion in trees and shrubs’ names to plant in order to block the noise from the big trucks.

    Thanks.