Vertical Gardens: Patrick Blanc

Taipei Concert Hall

French botanist Patrick Blanc designs gardens that defy gravity. His vertical gardens (or green walls) are amazing plant art grown on a massive scale. One inside a Portuguese shopping mall is larger than four tennis courts, and there's one in Kuwait that's almost as big. But Blanc's recently completed facade for the Athenaeum hotel in London (shown below) could be his most high-profile project yet. Looming over Green Park, it's an eight-story antigravity forest composed of 12,000 plants.

Blanc uses a kind of techno-trellis as the underlying structure: A plastic-coated aluminum frame is fastened to the wall and covered with synthetic felt into which plant roots can burrow. A custom irrigation system keeps the felt moist with a fertilizer solution modeled after the rainwater that trickles through forest canopies.

Blanc says his creations will always reach upward: "I leave horizontal gardens to others. I only think vertically."

Rue d'Alsace, Paris