Roadside Attractions

There is a road in Headwaters that I visit every year in May. Between the gravel shoulders and the cedars and tamaracks of the nearby woodland, yellow lady’s slipper orchids open their exotic-looking blossoms. In the Saugeen-Bruce Peninsula, these orchids grow in dazzling abundance along roadsides. Here they are rare, but that only adds to their mystique.

The cheerful patch of lady’s slippers are harbingers of high summer when our roadsides erupt into a dazzling riot of wild bloom – from blue chicory and black-eyed Susans to orange daylilies, pink sweet peas and purple clover, among many others. As summer recedes, these are followed by the regal purples and golds of asters and goldenrod.

But each year, just as this bounty of bloom reaches its peak, it falls victim to the blades of municipal mowers. The bad old days of roadside herbicide use are well behind us, but in aggregate, these cutting programs mean the loss of many thousands of acres of insect habitat – insects that pollinate plants and feed birds.

Some cutting along our roadside verges is certainly necessary to keep sightlines clear of trees and shrubs that might hinder a driver’s vision. That this cutting of woody vegetation allows sunlight to spark the growth of wildflowers is an unintended but welcome consequence.

However, in this age of declining biodiversity, perhaps it is time to manage this cutting more intentionally – to maximize and protect these wildflower havens throughout the year. Such an approach would reduce cutting frequency and be scheduled to avoid periods of peak bloom.

Most wildflowers don’t grow tall enough or densely enough to inhibit roadway visibility. Where they might, along some curves or roads with narrow shoulders, selective cutting could occur. Management that acknowledged the ecological value of roadside wildflowers might even leave some stretches of road uncut in some years, allowing flowering plants to set seed, reproduce, and feed seed-eating birds.

Beyond safety, works departments in Headwaters cite various reasons for cutting. In Caledon, for example, where cutting takes place at least three times a year, a spokesperson responded to my query about the rationale behind the practice by noting it also keeps “ticks and other insects away from roadsides.”

This response is puzzling. Ticks are undeniably harmful, but it is unclear how these worrisome arachnids would menace drivers or cyclists, and pedestrians tend to walk on the shoulders, not through the vegetation.

More puzzling is why we need to protect road users from “other insects.” How do insects compromise road safety? With the global decline in insect populations, long gone are the days when a drive in the country included turning on the wipers to clear bug-spattered windshields. And “other insects” include pollinators, and a vast array of insects that feed birds such as swifts and swallows. Aerial insectivores, according the 2019 State of Canada’s Birds report, are declining more rapidly than any other category of birds largely because of their diminishing food supply.

“Aesthetics” is another reason offered to support frequent road cutting. But aesthetics are in the eye of the beholder. Tidy, well-mown lawns are an enduring feature of our domestic landscapes, especially in the urban commons of our front yards, so perhaps it’s no wonder some of us want to see that routine extended to public roadsides. But increasingly more of us are pushing the aesthetic envelope by substituting trees, shrubs and perennials for the near ubiquitous grass, creating personal landscapes that are more ecologically friendly and far more interesting.

Perhaps this progressive thinking should be brought to the management of our roadside verges? Complete consensus is probably elusive, but with public attitudes evolving, it is worth seeking feedback from Headwaters residents to provide guidance for road departments. Cutting could be reduced on selected thoroughfares, with the results monitored and the community invited to weigh in with their impressions.

Other jurisdictions are already exploring the opportunities that roadsides offer to biodiversity. A National Planning Framework published in Scotland in 2009, for instance, proposed that “Major linear infrastructure projects such as railways, roads, pipelines and cables should be seen as opportunities to strengthen green infrastructure and ecological networks.” A subsequent report released in 2013, called The Management of Roadside Verges for Biodiversity, identified roadsides as potential “stepping stones” linking isolated fragments of quality habitat.

The Scottish report does not ignore the potential pitfalls of roadside naturalization and particularly notes that sightline safety is paramount. The report also acknowledges that wildlife such as butterflies and birds may suffer increased road mortality along naturalized verges.

A Canadian registered charity called Pollinator Partnership Canada (P2C) likewise acknowledges on its website that “some pollinators, including bees, are indeed killed by traffic, but the positive benefits of creating roadside habitat outweigh the losses.”

The Scottish report recognizes that the biodiversity potential of roadside verges differs from place to place – that a one-size-fits-all prescription for roadside management is not appropriate. Management regimens should be informed by soil type, existing vegetation and the moisture levels of individual sites.

Closer to home we can look to the Rural Lambton Stewardship Network and its subsidiary not-for-profit division, Ontario NativeScape, for some guidance. In 2002 RLSN naturalized 220 acres of Ministry of Transportation lands along 38 kilometres of Highway 40 between Sarnia and Wallaceburg with prairie grasses and wildflowers, and christened it the Highway 40 International Prairie Passage. Twenty-two years on, Jake Lozon, the public land manager for RLSN, describes the project as an “amazing” success.

Even so, Lozon acknowledges there remain competing views on how roadside verges should be managed. He told me some RLSN roadside naturalization projects are mowed regularly by adjacent landowners, even though the project locations are clearly signed as restoration sites.

The Lambton example also demonstrates the necessity of site-specific management of roadside verges. Though successful in Lambton, it would not necessarily work here. Southwestern Ontario soils and climate historically supported prairie and savannah habitats. Our soils and climate are different.

For its part, Pollinator Partnership Canada advocates for roadside management designed to bolster pollinator populations nationwide and paints a tantalizing picture of what might be possible: “A successful pollinator habitat project on a roadside or transportation corridor holds the promise of supporting the buzz of bees, the hum of birds, and the wondrous migration of monarch butterflies while bringing your community great satisfaction.”

With funding from the federal and provincial governments, P2C published the Technical Guide for Enhancing, Managing and Restoring Pollinator Habitat along Ontario’s Roadsides. The report opens with this statement: “With over 270,000 kilometres of roads in Ontario, marginal habitats such as roadsides are a significant, yet often overlooked resource for pollinator conservation.”

To do the math on one local example, take Mono Centre Road in Dufferin County between Highway 10 and Airport Road, a distance that includes about 10 kilometres of wild verge. About 1.5 metres (approximately 5 feet) are routinely cut from the sides of this paved rural thoroughfare. This amounts to the cutting of 3 hectares (7.4 acres) of vegetation – much of it wildflowers – two or three times a year.

Extrapolate that estimate to even a small portion of the 270,000 kilometres of roads in Ontario, and the aggregate amount of lost wildflower acreage reaches massive proportions. To reiterate, some cutting is required. But again, can we reduce the frequency and avoid prime bloom periods? Pollinator Partnership Canada thinks we can. It says pollinator activity should inform cutting decisions and recommends “annual or biannual mowing regimes” and waiting until “late fall when the pollinator habitat has finished blooming.”

P2C also encourages planting native wildflowers along our roadsides and the attendant reduction or elimination of “invasive” species. There are some noxious invasive species we should seek to control, such as dog-strangling vine, phragmites and giant hogweed. But naturalized non-native wildflowers such as chicory, Queen Anne’s lace and the various clovers merit a different approach. Attempts to replace these non-natives with native wildflowers would be a daunting prospect, likely doomed to failure. Further, recent research has found these non-native wildflowers may not be the ecological pariahs we’ve long thought them to be.

Surprisingly, many introduced species of roadside wildflowers are favourites of native butterflies. A paradigm-challenging study conducted by Dr. Heather Kharouba of the University of Ottawa found that native butterflies preferred to sip nectar from non-native wildflowers. Monarch butterflies, for example, visited non-native plants 58 per cent of the time. The findings suggest it is too simplistic to automatically consign all non-native flora to the negative side of the ledger.

Kharouba’s study also found that some non-natives bloom earlier in the year than natives, providing nourishment to butterflies, bees and other pollinators before the natives ramp up flower production. Non-natives such as Queen Anne’s lace can also feed caterpillars like those of the beautiful black swallowtail butterflies. Further, most of these introduced wildflowers flourishing along roadsides are present precisely because they have been visited by pollinators.

Of course, it’s not only insects that like non-native wildflowers. Many of us delight in the summertime tapestry of colour that daisies, clovers, orange daylilies (aka “ditch lilies”), chicory and many other introduced plants bring to our byways.

This is not to say non-natives should take precedence over natives, however. Natives such as asters, goldenrod and milkweed are brilliant ecological and visual stars and should be encouraged over introduced species where possible.

Milkweed, of course, feeds monarch caterpillars, and the asters and goldenrods are top-tier pollinator favourites. And aside from their ecological value, they are visually stunning. But recognizing that non-natives may also be playing important ecological roles may save us the time and treasure necessary to control them.

In response to climate change, all our local municipal governments are undertaking concerted reviews of their procedures and priorities to boost sustainability and enhance biodiversity. A new approach to the management of roadside verge habitats should be part of the mix. We need to look at research and projects like the prairie corridor in Lambton for guidance. We need to consult Headwaters residents and honour their feedback regarding roadside maintenance. While our towns and townships should be lauded for their commitment to keeping us safe through their cutting regimens, cutting should be modified to maximize the benefit of roadside verges for pollinators and butterflies, and to maintain the joyful tumult of flowers that brighten our travels through the countryside.

As you read this in the summer, know that in May I wandered once more along that special roadside in Headwaters, reacquainting myself with gorgeous yellow lady’s slipper orchids. These peerless wildflowers flourish along this roadside because of cutting that allows sunlight to reach them. They remind us that thoughtful cutting can create opportunities for wildflowers and the many creatures that benefit from them – including the humans who delight in their beauty. The key is the timing and the frequency.