Last summer, we had a tomato grow from a crack in the concrete at the bottom of our front steps. It ended up being our highest yielding tomato bush ever. The summer, we have this contender, growing with no visible means of support from a crack between the house and the verandah. I don't have high hopes for this bush, because it only gets minimal morning sun whereas last year's impossible bush got lots of sun. But, hey, when it comes to gardening, I am constantly being proven wrong, so why listen to me?
I'll keep you posted.