Yep, Malcolm is right on.

Depending on where you live, plants will grow as long as they have the right conditions to not only survive but thrive. In some cases, only dust in a damp crevice can provide enough of a growing medium for a plant to flourish!

Of course, there is always the scenario of the guy who forgets to move his car and this is what happens:

Given a chance, nature will find a way to grow.

Rick_HD_OC

There are always little cracks for seeds to fall into and germinate, wind blown dust can build up a little soil as well, plant roots can make the cracks bigger, in some cases destroying the buildings.
Given enough time you get something like this.

or even this