What type of indigenous plant or tree can I use to create a sound barrier?
I live in San Diego. My property borders a busy street and I have a narrow piece of land where I was thinking of planting bamboo. After reading about the effects bamboo can have, I am looking for a native plant that looks nice, adds privacy and also helps deflect the road noise.
The short answer would be that plants have limited ability to deflect sound on their own.
A more precise answer is that studies show that planted berms are much more effective in deflecting sound. The U.S. Department of Transportation recommends planted berms as an alternative to walls as an effective way to deflect highway noise.
In terms of the plants themselves, if you want to control the bamboo, you can
- use a high-density polyethylene barrier to keep it from spreading, or as an alternative,
- I would recommend an evergreen, something that will hold its foliage all year. I'm not from your neck of the woods, but a plant recommended on CaliforniaGardens.com is California bay, Umbellularia californica.
I would also recommend layering with native grasses and perennials to help hold the berm and create more variety in order to encourage greater biodiversity and a more interesting planting. Another useful resource for researching native perennials in your area is the website of the California Invasive Plant Council.
Finally, if you are willing to mix in some adoptive (but not invasive) non-natives that are drought tolerant, go to EvergreenNursery.com. Designing a sustainable landscape with drought-tolerant plants will keep your water bills down and lower your maintenance costs.
For more information:
Read Richard Heller's Ask A Pro Q&A, "I'm interested in planting bamboo in my yard. How can I keep it from spreading?"