An amazing story this is. In 2003 we got a new blacktop walkway/driveway that is at least 3 inches thick. On the walkway we got a brick pattern that is painted to look like brick, and it looks great, most people think it is brick. One day, while outside, I saw some black on one of the bricks and I assumed it was bird poo. This was on Monday. On Wednesday I went out to spray paint a model car, and while walking by I noticed that a Lilly of the Valley had sprung up THROUGH the walkway!! It's amazing that a little delicate plant could push up through at least three inches of Blacktop. It even has some blacktop stuck to it!