How to plant a roof garden

Make your own green rooftop in 3 simple steps
By Sharon Cohoon and Kathleen N. Brenzel

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. Click images below left for a closer look at some of the varieties.

“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