How to Plant a Roof Garden

This living roof is like a shag carpet with attitude. Growing a green roof is a cinch if you live in a damp forest where epiphytes―plants that don’t need soil―grow naturally.

“Stuff falls from the trees, then moss grows over it,” architect Roy Hellwig says of the spongy mat of ferns, lichens, and moss atop his house in Sequim, Washington. Below are a few varieties that grow on Hellwig’s roof.

Oregon Beaked Moss

Tree-Ruffle Liverwort

Frog Pelt Lichen

“It’s a fairyland of fascinating plants, fringed with curtains of moss.” To invite the forest to plant itself on his flat roof’s rubberized asphalt surface, Hellwig gathered moss from around his property and spread the “starter kit” on his roof. Lichens and more moss arrived.

The best part: These plants suck all the moisture and nutrients they need from the air, so no maintenance is required. And it’s lightweight―living roofs are often not practical because they’re too heavy.

Design: Roy Hellwig, Tormod Hellwig, Sequim, WA (360/582-1060)

1. In fall, scrape a handful of green moss from a rock or path (or ask a friend to share some).

2. Shred the moss into a blender with 1 cup buttermilk; mix to the consistency of a thick milkshake.

3. Paint the mixture onto the roof, a rock, or other surfaces where you want it to grow and spread. Damp, shaded locations are best.

Price: Just the cost of buttermilk ($1.80/qt.)

More: How to garden anywhere