MODA Green Roof
WinterCreek was hired to co-design and create what turned out to be the first completely native vegetated roof in the country.
We encountered several challenges in the design and implementation of this project. The first was to design a substrate suitable for a roof top planting in a dry climate. Most substrates are engineered for climates receiving significantly more precipitation than central Oregon, and we worked with research faculty and graduate students at Oregon State University in designing a planting mix for retention of the greatest amount of available moisture possible. Plant choices were based on community structure, rooting depth, and tolerance to extreme conditions experienced by roof top plantings. As with most of our projects, once we created the functional base of the planting (substrate, plant community, microbial populations) we had several appropriate species colonize on their own.
The design and construction emphasize biodiversity, both above and below ground. Over 40 individual plant species were installed and the substrate and planting technique emphasize accentuate soil fungal and bacterial communities for a self-sustaining system. No fertilizers or pesticides were used in construction of the roof garden. Species diversity increases resistance to pathogens or insects in created environments, and aids in the ability of a landscape to recover after disturbance. These two basic ecological concepts are key for a successful native plant landscape, and critical for a completely artificial environment such as a roof garden. Our focus on maximizing species diversity has been a major factor in the success of this project.
The MODA roof garden serves as a model for green roofs in dry climates. We have presented this project as a successful example to Oregon State University, the Nevada Landscape Contractors Association, and the Environmental Protection Agency. We received several national awards for this project, and were interviewed about this project by Florida Public Radio. It's been a very good project.