The Return of the Natives: Designing and Planting Hedgerows for Pollinator Habitat to Bring Wild Diversity Back to Farms and Gardens
By: Gary Paul Nabhan and Amanda Webb
Native pollinators, it seems, were once forgotten as playing an essential role in providing ecological services for food security, but no longer. We have witnessed a surge in grassroots interest in returning pollinators to their proper place in sustainable agriculture, as witnessed by the enthusiastic participation recently seen at a workshop regarding on-farm pollinator habitat restoration in the U.S./Mexico borderlands.
The workshop featured practical teachings from Sam Earnshaw of Community Alliance of Family Farmers, who has helped plant or restore over 300 miles of pollinator-attracting hedgerows in Western states. Other speakers included Jo Ann Baumgartner of Wild Farm Alliance, Amanda Webb, Gary Nabhan and Laura Lopez Hoffman of the University of Arizona, Susan Wethington of the Hummingbird Monitoring Network, as well as permaculturist Kate Tirion and ecologist Ron Pulliam of Patagonia, Arizona. Co- sponsors included Wild Farm Alliance, Borderlands Habitat Restoration Initiative, Hummingbird Monitoring Network, the Sabores Sin Fronteras Foodways Alliance, and the Kellogg Program on Food and Water Security for the Southwest Borderlands, University of Arizona, all in support of the larger efforts of the North American Pollinator Protection Campaign or “Pollinator Partnership”. Over thirty-four residents of three counties in Southern Arizona became engaged with hands-on efforts to bring a diversity of pollinators back to borderlands farms, gardens and ranches.
Following introductions, the workshop in rural Santa Cruz County was launched with lectures by special guest presenters. Jo Ann Baumgartner began by talking about efforts by the Wild Farm Alliance to promote forms of agriculture that protect and restore wild biodiversity. She also responded to food safety concerns that wild animals on farms are a risk to production operations. She highlighted habitat restoration strategies that minimize the potential for contaminating crops with diseases that are then transferrable to consumers in ways that might otherwise compromise human health. She emphasized the importance of understanding how wildlife, livestock, and other biota can act as vectors or as filters for pathogens on farms. She concluded that wild species can provide more benefits than risks to farms if ecologically managed.
Sam Earnshaw of CAFF then shared insights gained from his extensive experience implementing hedgerows, green buffers and other wild habitats on farms in California. He presented many ways that a hedgerow can provide needed support services to a growing operation, and suggested plants that could be used for different applications. The photos in his presentation helped illustrate how hedgerows function to address site-specific issues, the different forms hedgerows may take, and how they can support pollinators as well as other vertebrate and invertebrate species that can act as natural pest control for crops.
The hands-on portion of the workshop took the form of installing native plants as hedgerows at two different sites. Gary Nabhan took this opportunity to talk about specific features unique to each of the sites, the crops grown there, and the desired functional outcomes for each hedgerow after it is established. In addition to discussing how the hedgerows would support native pollinators, he led a demo on constructing and providing bee nesting structures and showed how they could be installed on-farm, at home, or in the garden. Jo Ann, Sam, and Gary provided continual information to participants about the ecology of on-farm hedgerows through guiding presentations and interactions with individual participants.
The hedgerow designs at the two sites reflected site-specific goals of each of the hedgerows, and both were comprised of a different suite of plant species to reflect those desired outcomes. Gary Nabhan led the design and implementation of plantings dominated by native vines, sub-shrubs and wild flowers (mostly crop relatives) alongside a mesquite retaque fence. This site was located on a clay-dominated ridge between the Native Seeds/SEARCH and the Almunya de los Zoplilotes orchard, while Amanda Webb, a graduate student from the University of Arizona, led the design and transplanting of woody perennials at the Rogers-Wethington orchard on a floodplain. These examples provided participants with the opportunity to see two different applications of the forms and functions of hedgerows under local conditions. Plant installation at both sites ultimately included transplanting woody vegetation (shrubs, vine and trees) as well as the sowing of native annual and perennial wildflower seeds. The spent flowering stalks of desert sotol and century plants were integrated into fences to serve as nesting habitat for carpenter bees at both sites. Many on-site discussions were inspired by these hands-on experiences that give people skills in how to plant native plants, to construct nest boxes, fences and rainwater harvesting structures, to plan irrigation regimes, and to extend the flowering season to attract and keep a variety of pollinators on the farm.
There were other scientists and farmers present who gave summaries of the related work they do with pollinators. These included Susan Wethington who talked about the mission and work of the Hummingbird Monitoring Network, Laura Lopez-Hoffman who described her research on nectar-feeding bats, and Ron Pulliam who talked about the on-going pollinator habitat restoration and education efforts of the Borderlands Habitat Restoration Initiative. These short talks provided an expanded view on pollinator conservation and research while emphasizing that effective pollinator conservation cannot be isolated to one farm or species, but should be implemented for diverse species at the landscape or regional level with a multitude of collaborators, supporters, and projects. The point was made to participants that the renewed planting of hedgerows on farms is an important step in this larger kind of effort.
Feedback from workshop participants has been overwhelmingly positive. Along with hearing the lectures and participating in hands-on experiences, they left with a packet of printed information covering a wide breadth of related topics, including information on selecting plants to fit different sites. Printed materials included recommendations for planning pollinator-supporting hedgerows that can thrive in different habitats throughout Southern Arizona.