Building a Garden in the Sky

 
As the Urban Forestry intern, I recently had the opportunity to see the construction of the green roof atop the 11 story parking deck at the Cira Center South in Philadelphia. Jason Lubar, a Morris Arboretum Urban Forestry Consultant, was asked by the project’s green roof designer Roofmeadow, to assess the support systems for the planted trees.  As the green roof is 11 stories up, the wind dynamics are more intense than at street level, and the trees need a flexible, but sturdy support system to properly establish.

Green roofs have come a long way, and are no longer just moss and sedums. Roofmeadow created a beautiful design at Cira that includes:

• A grassy lawn with a small hill  
• A meadow with tall grass such as prairie dropseed, reed grass, big bluestem and perennials such as liatris, veronica, pinks, beards tongue and alliums
• Several trees including honey locusts, swamp white oaks and redbuds
• Walkways and plaza of permeable paving
• A rainwater storage system that will direct rainwater into the lawns and gardens and will mitigate the first couple of inches of rain.

The project will be completed soon, and will provide a beautiful garden and event space for the tenants of the adjacent 40 and 50-storied towers to visit and view from above.   Along with the aesthetic benefits, the garden will increase biodiversity, remove pollutants and mitigate stormwater discharge.  The green roof garden is a wonderful example of Philadelphia’s green infrastructure.

Article contributed by Trish Kemper, the Martha S. Miller Urban Forestry Intern

Urban Forestry and Philadelphia Navy Yard

by Rebekah Armstrong, Martha S. Miller Endowed Urban Forestry Intern

The Morris Arboretum Urban Forestry Consultants have been spending a lot of hours at the opposite end of Philadelphia recently. We’ve been inventorying, assessing, and mapping 2,000 trees in the Philadelphia Navy Yard (PNY), at the southernmost end of Broad Street. PNY was the first naval shipyard in the country and the U.S. Navy still operates some facilities there. Aker, a shipbuilding company, now manufactures commercial ships at PNY. Then there are companies like Urban Outfitters that have reused the old Navy buildings for their headquarters. Point being, it’s a very cool place to spend time in: giant old ships and abandoned structures next to an active shipyard, constant renovation, and new construction.

During our inventory and assessment, we saw beautiful examples of big healthy spreading trees in lawns and then some sad cases: new trees battered by construction equipment and rubbed to death by deer, e.g.

In general, when we do field work, the urban forestry consultants look for hazardous trees – trees with branches that might fall, trees that are splitting – and then look at the overall health of the trees. We also measure the trunk and canopy, records the species, and map the trees’ locations. We then make recommendations for our clients and provide them with a complete map and inventory of their trees to help them manage their portion of the urban forest. To learn more about the Morris Arboretum Urban Forestry Consultants visit: http://www.business-services.upenn.edu/arboretum/arboriculture.shtml