I've just listened to a cool interview on BBC radio 2 (hoorah for internet radio) about guerrilla gardeners who sneak around at night gardening on waste ground and other public areas like roundabouts etc.

There's probably a dodgy side to it (already people are phoning the show saying don't plant trees on roundabouts!), but it sounds great to me!

Here's their website Guerrilla Gardeners.

Apparently they have lots of tactics, including 'seed bombing' where they just chuck a load of seeds out of the car window. I think I've seen something similar in Paris, although it only seems to grow pigeons...