on eco-graffiti

Reflections on French nudity and dressing aside Nice showed me something i can't believe that i've never seen before: graffiti on plants. No spray paint here, it looked like the graffiti had simply been etched into the cacti. Is this a new eco-friendly form of graffiti? No wasted spray, no spray-can necessary, no cleaning possible; it might be the future of graffiti: artists are a very conscious group.
Now i have no idea how expensive being a graffiti artist is, in fact, all of my graffiti knowledge comes from a book i browsed whilst waiting for my hair to be cut and the odd amusing print of Banksy pictures. Some quick research revealed that a spray-paint can costs between £3 and £15, overalls cost £5 a time and a paint mask sets you back about £20. This struck me as relatively cheap for art but, and you'll be shocked at this, during my research for a sharp implement with which to etch, i came across five sticks outside my house and several stones all of which were free! This means that not only is plant-etching eco-friendly but it's cheaper too. (More sensible readers might note that you could easily come by a sharp object for a very small sum and it would likely be a one-time purchase unlike spray-cans.)
I know that in the UK we are relatively relaxed when it comes to graffiti (well at least when it is done by Banksy) and this seems true of many of the countries that embrace it as an art form. Eco-graffiti (as i shall from now be calling it) deals with what i imagine can be a big problem: over-congestion. It must be (i say with no real knowledge) a problem. There is only so much wall space. Plants, however, will repair these parts of themselves renewing the canvas for someone else. They might even give an interesting effect where old scar tissue gives a background to new pictures without confusing the image. Even if you aren't too bothered about the environment cacti offer a good canvas for you because the local authorities are not able to clean off your art but are also unlikely  to actually remove the plants.
It seems that everyone is a winner with eco-graffiti and even though i have only seen it in Nice i think it just might take off.