The Art of Caring for Green Rooftops

While visiting the Garden at the end of the year, you may have noticed our gardening team on lifts, caring for the plants growing on the Garden’s Cultural Village rooftops.

The Ecoroof, or “living rooftop,” tile maintenance is something the garden team must do at least a few times a year. But since it requires safety equipment and machinery, it takes much more time than most tasks on the garden’s grounds. Nature evolves constantly, and the dozen or so sedum species initially installed on the rooftops in the Cultural Village have self-selected their microclimates and have now settled in with the inevitable moss.

The material used for the Ecoroof is a porous ceramic paver called ‘Greenbiz’ made from a by-product of the Komatsu Matere Co., Ltd. fabric industry, who also donated half of the roof tiles used.

The tiles were shipped to Portland Japanese Garden from Japan, and the Cultural Village roofing constitutes the first project of its kind in the United States to use this material.

“We performed multiple studies for installation and growing best practices prior to construction, and now a few years in, we are still learning how to best maintain our living roof,” said Desirae Wood, Garden Asset Manager. To date, Wood says, maintenance has involved planting, weeding, re-vegetation, sedum trimming, and fine tuning the irrigation.

“We continue to learn a lot and are happy to encourage the visual transition of the buildings into the native forest environment – something architect Kengo Kuma strove for in his design of our Cultural Village.”

Garden Happenings

As we welcome a new year, our gardeners have been hard at work completing projects that are rooted in Japanese tradition and symbolize the start of a new beginning.

• Created handmade Kadomatsu arrangements, which can be seen and enjoyed throughout the Garden in the beginning of January
• Organized and cleaned the entirety of the Garden, from the eight gardens to the gardener’s garage, and beyond
• Replaced old bamboo spouts throughout the Garden
• Cleaned all of the pine trees to prepare them for new growth