Public art existed all along, but ecological art just naturally grew out of my thinking and writings in that area for years. I didn't get involved in it; I started what then became a movement.

I study what I work with. I studied all these different fields of science that I needed for my work. I studied how to mine a landfill and what to plant in it. It's fascinating because you learn a new field each time.

If I like a person, I like them. I may like the art and not like the person.

The tree is made by nature, mathematics by people. And combining the two is creating this beautiful alliance between humanity and nature. That's why my forests are mathematical expansion systems, all of them.

Every one of my works, when I'm looking back, becomes some kind of solution, or something to concentrate on. Something to pay attention to and maybe change direction.

I never considered myself a performance artist.

Anything important has to be almost invisible. And underrated. So the understructure should be underrated, but strong enough to hold the earth.