How do plants grow out from under concrete through the concrete?

Question

Concrete is sold and stuff, but yet, weak plants break through it and grow, how?

Answer 1

the roots underneath are strong. plus they just find a way up

Answer 2

It's not weak plants that break through concrete, but strong plants!  They have to be strong to be able to push their roots against the heavy concrete.

Roots grow downward and toward water, so if there's water between the cracks of concrete, that is where the roots will go.

Answer 3

From seed that gets in the cracks, Not through the concrete!

Answer 4

Concrete is porous, not solid. The plant makes its way slowly through it and breaks it apart because of this.

A stone is solid. Concrete is like a lot of little stones packed together with adhesive (for use of an analogy).