by the Transportation PPN leadership team
For the 2021 ASLA Conference on Landscape Architecture, the Transportation Professional Practice Network (PPN) teamed up with the Planting Design PPN to engage in a lively campfire discussion about planting design for pollinators.
Pollinator planting has been and remains a hot topic (see the December 9, 2021 Field post by Liia Koiv-Haus, ASLA, “Making Space for Pollinators,” and “Roadside Realm” from the March 2021 issue of Landscape Architecture Magazine). Both PPNs agreed that preserving pollinator habitat is important, but the methods and resources used to create habitat differed. This is due, in part, to the landscape scales in which each PPNs’ members typically practice. Other differences included maintenance abilities and strategies, budgets, and “owner” motivation. Planting design practitioners are often hired by property owners intent on creating habitat; transportation practitioners are usually required to justify spending public dollars on habitat creation and not on other, more easily justifiable, competing interests (such as roadway improvements and accessibility).
Transportation PPN leaders started the discussion by outlining federal and state resources that departments of transportation (DOTs) use to inform policy and practice decisions about pollinators. The U.S. Department of Transportation Federal Highway Administration’s Pollinators and Roadsides: Best Management Practices for Managers and Decision Makers is the primary reference for state transportation agencies. The document elaborates on a variety of techniques used by state DOTs, four of which also appeared in Liia Koiv-Haus, ASLA’s “Making Space for Pollinators”—altered mowing practices, reduced herbicide use, protection of existing stands of native vegetation, and re-seeding efforts post construction.