Question
I live in the Houston, Texas area and our house backs up to a road. I would like your suggestions on planting a natural noise barrier for my back fence.
Thanks

Answer
Here is a site that discusses the problem:
http://www.ehow.com/how_2044848_buy-noise-barriers.html

If you have the room, an earth berm or solid feature like a wall will diflet the sound much better than trees, shrubs, or vines.

Unfortunately, sound is a vibration, and leaves and twigs just don't do a good job of re-directing or attenuating this.  The best is a wall and distance from the sound source.  Adding plants is more for aesthetics that a noise cure.

If that is not practical, maybe you can add "white noise" in the form of a flowing fountain or wind-chimes.  I have found that this type of masking helps in making the larger street noise less noticeable.

Again, sorry for being the bringer of unfortunate news.  ~Marc