Highway sound barrier plants
I am looking to plant some sort of plants to act as a sound barrier and visual barrier between my backyard and a highway. I have a privacy fence and then a chain link fence at the back of my property. Then about 20 feet of sparsely wooded area then a fairly business highway. My backyard slopes down on the left side so the fence acts as a barrier from the highway only on the higher right side of the yard. I attempted to plant bamboo on the 20 foot county-owned buffer zone last year, but it did not take. The area is fairly shaded due to some 25 ft high pines but they are pretty spaced out. Something that would grow fast and thick and at least 8 ft high would be great. I've heard oleanders are very hardy and drought resistant. Any advice would be greatly appreciated.