Case Study. VA Hospital.
Tacoma, Washington

The first of two shipments arrived as scheduled, but the roof was not ready for planting at that time. The pallet shippers were offloaded and held at the site without shelter or water available for a few days while the work on the roof was completed. The second shipment arrived two weeks later and the plants were installed immediately.

The pallet shippers allow for a small footprint and provide airflow and protection for the plants which was helpful in this situation. If a water source was available, the plants could have been lightly irrigated while still packed. Shown: Sedum reflexum 'Blue Spruce' in 72 cell trays.

Just over 41,000 plugs were planted into 4" of media at two plants per square foot. Varieties used: 58 Cell Festuca 'Elijah Blue', 72 Cell Achillea 'Terra Cotta', Sedum rupestre 'Angelina', Sedum reflexum 'Blue Spruce', Sedum hybridum 'Immergrunchen', Sedum spurium 'Red Carpet', and Sedum kamtschaticum 'Variegatum'.

The green roof, totaling approximately 20,000 square feet, was planted in early August 2009. After only a couple of weeks of warm, sunny weather the plants are well established and starting to spread. A permanent irrigation system was installed on the green roof, also.

At seven months post installation the Sedums are filling in nicely. The semi-deciduous varieties and clumping forms of Sedum, such as Sedum hispanicum 'Purple Form' will take just a bit longer to fill in than the spreading forms. It's very early spring, so the perennial Achillea and Fescue are just starting off again, but are already well established from the season before.

A full year after planting, the green roof is almost completely filled in. Established plants show off their brightly colored blooms in mid-late summer. With waves of yellow flowers mixed with rich red, green, and purple foliage, this roof is striking.