From busy streets to congested freeways, airports, and close-in neighbors, city life has no lack of noise, and while we can’t get rid of all of the noise around us, we can ensure that our landscapes do the best job they can to reduce its impact on us — and our clients.
For the contractor, this means choosing and creating hardscapes and planting plans that either absorb, deflect/reflect, or refract incoming sound. While this sounds very technical, a quick rundown of each makes them more understandable:
Absorption: When sound vibrations are trapped, it’s called “absorption.” Fortunately, many plant types contribute to sound absorption and keep noise from negatively impacting outdoor (or indoor) events.
Deflection/Reflection: If a structure or object cannot absorb a sound vibration, if it’s a significant enough structure, it can bounce the vibration back, often to its source.
Refraction: When sound is dissipated or dispersed, its impact greatly lessens. Rough surfaces or planes come in handy when you’re trying to incorporate refraction into a design.
Here’s how to design for noise reduction.
Anything not plant-related that is added to the landscape has the potential ability to absorb, defect, or refract sound.
Most properties have fences, and the thicker/taller/denser the fence is, the better it will be at deflecting noise. While almost any kind of fence is better than none for this purpose, those that are stucco, brick, or stone do a much better job at deflecting noise than a wood fence with gaps. Grow a sound-absorbing vine over the fence, and you’ve created yet another layer to diffuse sound.
If the pathway has a bit of a rough texture, such as those made from gravel or flagstone, it can assist in refracting, or breaking up, noise.
If you can’t absorb, reflect, or refract sound, try distraction instead. Larger water features direct the attention to the sound of the water instead of honking cars. For the most flexibility, specify a water feature that the client can amp up during rush hour or tone down during calm evenings in the garden.
Another great sound distractor is wind chimes, but not just any wind chimes. If your client is already irritated by the sound of I-35 a half mile away, they’re not going to be calmed down by the high-pitched tinkling of dozens of tiny wind chimes. Help your clients by selecting deeper gong-type wind chimes. These double as sculptural elements, as well. The deep tones ground and relax much better than smaller chimes.
Another great distractor is music, so, when possible add outdoor speakers to air the clients’ favorite playlist. There’s nothing like good beach music to make someone forget they live in the concrete jungle!
Thoughtful plant selection and placement goes a long way to reducing noise pollution in the garden.
Any plant with thick leaves, thick and rough bark, and evergreen foliage plays a big part in reducing sound bouncing around in a space. For a one-two punch, create an evergreen hedge with several layers of plantings in front of it — this layering effect provides a more solid border, making it more difficult for sound to penetrate. Succulents are excellent sound absorbers, too!
Tall plantings (large trees, taller shrubs) accomplish two things at once — their taller forms deflect noise while also shielding the viewer from the source of the noise. Consider a busy street in front of a house, for example. Taller plants, when strategically placed, can block the view of the street; and sometimes, out of sight is also out of mind.
Plants with movement
Plants with natural movement can conceal unpleasant sounds, or at least draw your attention to them and away from the noise. Choose trees with rustling leaves or ornamental grasses with fine-textured leaves that blow in the breeze.
While lawns have become something of an unwelcome or even inappropriate landscape feature in drought-prone areas of the United States, there are situations in which lawns serve a purpose. Their broad expanse of rough, leaf blade texture goes a long way to help refract sound waves. This is particularly important in more modern landscapes with minimal plantings. Even a bit of lawn growing between paving stones can have a significant impact on reducing the echo chamber in the condo courtyard.
Wooded areas arguably do the best job at refracting noise because they are composed of layer upon layer of larger trees, rough bark, smaller branches and twigs, and a woodsy forest floor. If your clients have a larger property, consider creating a woodland planting area for the very purpose of reducing sound — plus, woodlands are impressive landscape features.