Bringing Flower Power Back to California
Protecting out roadsides with flowers could save our DOTs millions.
Roadsides are a natural place for native flowers to grow. Before the creation of synthetic herbicides and the chemical industry-imposed concept that earth should be "clean" and bare, flowers like milkweed lined rural farm roads from early spring to late summer. Most of our highways are now sprayed with pesticides to keep vegetation down, but historical practices show us that there is another way, and it's resurfacing as a solution to habitat loss, water & air pollution, invasive species management, crop pollination, and climate change.
In January 2023 Assemblymember Connolly introduced Assembly Bill 99 to require Caltrans to respect resolutions passed by counties banning pesticide use on state highways. This bill is shedding light on California's use of pesticides (like RoundUpTM) on highways throughout the state and opening up discussion on what roadside maintenance would look like with a lot less chemicals.
Enter "Pollinator Highways". President Obama noted the opportunity roadsides could provide in habitat creation as part of his federal strategy to promote the health of honey bees and other pollinators. Pollinator Highways have been studied by the University of Florida as a way to increase habitat for beneficial insects like butterflies and bees while decreasing maintenance costs and increasing adjacent crop yields. The research team found that pollinator species flourished when native flowers and grasses were planted next to highways and allowed to grow with minimal or no mowing. This is the world that opens up to us when we move away from chemical road maintenance.
The Florida Department of Transportation has been discovering the benefits of pollinator highways and has planted thousands of acres of roadsides with native grasses and flowers. This has led to an estimated total value of over $500 million annually! FDOT estimates that this amount could be doubled if "wildflower areas were designated and sustainable maintenance practices such as reduced mowing were widely adopted." FDOT listed specific benefits include pollinator services, carbon sequestration, improved air quality, reduction of invasive species, pest control by wild insects, runoff reduction, and aesthetics (see graph below.)
https://rosap.ntl.bts.gov/view/dot/55914/dot_55914_DS1.pdf It's worth noting that native plants along roadsides serve as powerful filters for pollution. Most highways are lined with ditches that flow directly into adjacent waterways. Plants such as grasses and willow have been shown to offer natural filtration to polluted water, removing chemicals like gasoline, oil, and lead before it enters sensitive environments. When pesticides are used on roadsides, the earth is bare and pesticide-laden dirt easily becomes flow-clogging sediment in nearby streams. If roadsides were vegetated, the soil would stay in place. Roadsides managed for habitat also combat climate change. Healthy soils with active fungal networks are powerhouses for sequestering carbon. If the soil is treated with chemical herbicides, however, the balance of beneficial fungus is impaired and the soil cannot capture carbon from the atmosphere. Synthetic herbicides are also manufactured from fossil fuels so cutting them out of routine road maintenance naturally reduces climate impacts. Though the ability of roadways to serve as beautiful interconnected tracts of habitat for pollinators, they can also, in some cases, mean the spread of weeds considered to be "invasive species." Nature abhors a vacuum. If we leave bare earth resulting from repeated pesticide use, nature will fill it in with something. If the soil is degraded, it will be filled in with the hardiest, toughtst plant, which oftentimes is a thorny plant that is considered "invasive." If instead of leaving bare earth we healed the soil and planted plants that we (and native pollinators) like along our roadsides, in time this will naturally crowd out the unwanted species while creating a functional habitat corridor. Pollinator highways have also been shown to limit the spread of invasive insects by inviting native beneficial insects to come in and take care of the problem before it creates issues for commercial farmers. There is a huge potential for roadsides to become wildlife corridors and provide valuable habitat. Pollinator Highways are a proven non-toxic alternative to roadside spraying and are common in numerous climate zones throughout the United States. By working with the natural world instead of against it to solve our biggest problems, we can save a lot of time and money. There is a whole new reality that we are being invited to step into that could benefit everyone: Caltrans, farmers, and communities, all together, if we could just see past the chemical paradigm. It's time to bring flower power back to California! Sources: http://rightofway.erc.uic.edu/wp-content/uploads/2018/05/2A4-FDOT-ecosystem-services-roadsides-report.pdf http://fnpsblog.blogspot.com/2014/06/study-roadside-vegetation-can-provide.html https://obamawhitehouse.archives.gov/the-press-office/2014/06/20/presidential-memorandum-creating-federal-strategy-promote-health-honey-b https://www.flawildflowers.org/fdot-wildflower-program-procedure https://www.nurserymag.com/article/ufifas-mowing-pollinators/ https://bioone.org/journals/florida-entomologist/volume-98/issue-4/024.098.0412/Reducing-Mowing-Frequency-Increases-Floral-Resource-and-Butterfly-Lepidoptera/10.1653/024.098.0412.full https://www.icoet.net/2019/program/presentations/102 https://www.pollinator.org/roadsides https://www.pollinator.org/pollinator.org/assets/generalFiles/Maintaining_Roadsides_for_Pollinators.pdf https://rosap.ntl.bts.gov/view/dot/55914/dot_55914_DS1.pdf