I have found a cool site that showcases some Balloon interventions amongst hundreds of other stuff, but right now I'm all about balloons....Broken City Lab
On here I have managed to find out about this artist called William Lamson who uses alot of balloons for intervention type art work and it is all very very impressive, and makes you think 'how the hell did he manage that?!!?'. Trust me...you'll be amazed.
Another cool balloon based intervention I liked is the ‚ÄòFlower bombs‚Äô which are made from biodegradable plastic (PLA), that is painted with water-based chalk, (created by Studio TX) and filled with a few seeds. As the bag begins to break down (which takes 4-6 months), the seeds land on a base of sod and begin to flower. I can‚Äôt see this working down the Hoe as there are too many people who use the area, and I can see these getting destroyed or stolen by drunks!!
Ace idea though, could be used to replenish areas that may only be accessible at certain times.