This reminds me of the street next to ours. Was walking to the bus stop a few weeks ago and noticed a plant growing out of a crack in the pavement - thought it looked vaguely familiar but just carried on walking. No-one has pulled it up and it's now a very healthy looking bush tomato plant! It even has flowers and fruit forming on it!! So next year I'm going to water my toms with dog pee... :o
Cheers,
Rob ;)