Why We Need More Ivy
Seattle has a graffiti problem. Seattle has an ivy issue. I have a solution. Why not promote the growth of ivy along the many walls lining our freeways? Anyone who lives in this part of the world knows that ivy needs little encouragement, and less maintenance, to move in and overwhelm its surroundings. So WSDOT would not even have to work hard—if they did, it would help—and soon Seattle’s freeways walls would sport a verdant skin of protection that, I suspect, most graffiti practitioners would avoid.
At least a couple of cities, including Tacoma, have tried to do just this: use ivy to prevent graffiti. In Anaheim, California, a location that lacks our lovely precipitation, they use both real and fake ivy, depending on water availability and precipitation. The city’s Chief Communications Officer told me that there are some issues but it “still makes sense” to use ivy as an anti-graffiti measure. He also noted that “you might have a better climate for supporting [real] ivy.” That’s an understatement and one that offers some true benefits in incorporating live ivy over any ersatz vines.
Consider a typical freeway wall of bare concrete, typically the lovely color of oatmeal, it’s bland, bakes in the sun, and reflects sound. If the wall was covered in ivy, it would be green, one of humanity’s, and the natural world’s, most popular colors. Because green is often associated with soothing feelings, ivy covered walls might benefit society by reducing the red anger of road rage. Studies have also found that ivy creates its own microhabitat on walls and reduces extremes of temperature and relative humidity. Not only would ivy-surrounded freeways have less graffiti, they might ameliorate climate change and help keep Seattle a bit cooler, if not hipper, too.
In addition, ivy has a bio-protective role, acting as a particle sink and reducing air pollution impacts. (Studies show that vehicle-generated pollutants cause more premature deaths than car accidents.) As any city dweller has experienced, particulates are rife in the urban environment, especially in dry weather when precipitation isn’t scrubbing the air clean. A study in Oxford, UK, found that the large and moist leaves of your typical ivy are an “ideal receptor” and that an ivy canopy encourages particle deposition by altering air currents, particularly in high-traffic areas.
Ivy also provides a solution for one of humanity’s persistent problems, the noises created by us and our beasts of burden, be they handcart, horse, or car. I imagine that you have noticed that hard surfaces reflect (replacing the term amplify) sound and that people sometimes try to address this issue by putting up egg cartons. Although I think egg carton-lined freeways is a splendid idea, growing ivy is a bit more practical. Once in place, the thermo-viscous boundary layer of ivy leaves will cut down on road noise by attenuating sound waves. The leaves will also interfere with and reduce these waves, as well as reflect and scatter them, ultimately quieting the urban cacophony.
Luckily for those in the PNW, another one of our highly successful, often-thought-of-as-a-undesired-non-native plants, the Himalayan blackberry, also has leaves and dense growth that could contribute to noise reduction. Plus, blackberries bioaccumulate heavy metals, such as lead, zinc, copper, and cadmium, which may not be good news for those who eat the luscious berries but is good news for those of us who breathe. The thorny nature of the stems would be a further additional deterrent for graffiti people, further making blackberries ideal for freeway walls.
Clearly, we are never going to get rid of ivy or blackberry. Nor will people stop tagging and painting the blank walls along freeways. So, why not embrace a quality we loath, the plants’ rampant growth, and turn ivy and blackberry toward taking over our freeways ways instead of our yards and parks. It’s the natural thing to do.
For those who don’t get the Seattle Times, here’s a link to the excerpt from Spirit Whales and Sloth Tales: Fossils of Washington State.
Apparently, there are still a few tickets left for my talk at Ivar’s Salmon House on Wednesday, September 27. I will be talking about Lake Union and the Ship Canal.
you said, “hard surfaces amplify sound”.
while hard surfaces don’t generally do much to make sound go away, they cannot amplify it, they merely reflect it. a surface in general will reflect and absorb, the harder and smoother it is the less it will absorb and the more it will reflect. however, multiple hard surfaces working together can reflect and focus sound creating loud spots. once a sound leaves it’s source it will decrease in energy in open space according to an inverse square law.
ps: i like the ivy vs graffiti idea. good use for an otherwise evil plant.
I like the concept but I'd prefer a native plant with similar characteristics, if one exists.
I'd be really concerned with unintended consequences - ivy aggressively expands its domain, as I well know in my damn backyard!