Is it possible to cover a wall from the top down with plants?
We have a seven-foot brick wall that is regularly tagged with graffiti. Instead of wasting more money on graffiti removal or investing in barely effective anti-graffiti coating, I've been pondering whether we could cover the wall with some kind of plant. My thought is that we would mount planters on top of the interior side of the wall and somehow encourage the plant to grow over the top of the wall and hang down on the wall's exterior side. Is that even possible? What type of plants do that?
I know nothing about gardening and the one gardener I know seemed stumped. The exterior side of the wall faces south and would have plenty of sun. We're in USDA Hardiness Zone 8b and PlantMaps Hardiness Zone 9a if that helps.
I've searched online and found a lot of information about covering walls with climbing plants from the bottom-up. However, this isn't possible in our situation because the wall borders the public sidewalk so we can't place planters in the sidewalk. Also, I'm sure the building's owner does not want any plant attaching itself to the wall or something that will become a nuisance.