Workers tile a model of the California Academy of Sciences’ curved roof with coco fiber trays.

Covering 16,000 acres in Carmel Valley, the Rana Creek Nursery sprouts native grasses, sedums and fruit trees. Amid the lively landscape, a business in green roof plants has begun to blossom.

When the company got started in the mid-90s, its business was focused on California native plants for restoration projects and gardens in the West Coast’s Mediterranean climate. Under the direction of Executive Director Paul Kephart, the company expanded its work on green roofs into a Living Architecture practice, which helps design and build green roofs. Green roof plants now make up about half of the nursery’s business, said Cooper Scollan, nursery manager for the company.

Landscape architects and nursery staff work together to specify plants for different applications. For green roof projects, the nursery often helps develop a “palette” of organically grown plants that meet both the practical goals (such as stormwater management or insect habitat) and aesthetic goals of a project.

The company has also successfully piloted an innovation that could prove a boon to business: core fiber trays. A new tool for growing and installing green roofs, the 17-by- 17-inch potting trays are made from reclaimed coco fiber, reinforced with a wood band around the top.

Planted trays can be installed on a roof surface much like tile on a floor, where plants’ roots grow through the fiber into soil on the roof surface. Over time, the coco fiber breaks down, adding organic matter to the roof surface.

The trays allow Rana Creek to plant and establish small sections of the roof before installation. The trays also help the company avoid using plastic potting materials that create waste and “won’t stand the test of time,” Scollan said. “We’re getting a lot of new proposals to use these trays.”