“Ditch Weeds”
The often-overlooked importance of roadside habitat and why we should stop spending money trying to keep them trimmed and mowed.

Staff contribution by Kristen Sandvall

image of yellow ladys slipper (Cypripedium parviflorum)
Cypripedium parviflorum (yellow lady’s slipper) along and unmowed wet roadside edge in Halton Region, ON

We drive by them everyday and so they seem of little importance as we rush to work and then rush back home after work.  Often there is a disconnect in our brains about the plants which have managed to find a home in our manmade roadside constructs. Some places it has become a place for invasive plants to take hold and spread, but in other cases it has become the only place some native plants have a place left to call home.

Roadside Edges Have Become An Increased Habitat For Plants, Insects, and other Wildlife

We often forget or sometimes don’t know what an area once looked like before development.  Whether it be for agriculture, subdivisions, malls, or parks. What was land once rich with slopes and hills, forests and grasslands, streams and wetlands is now cleared, flattened and drained. What we are left with is relatively flat land with a set of interconnecting ditches that lead “somewhere”.  This has drastically reduced habitat for many plants, insects, and other wildlife.  We often think of the patches of forests we leave dotted in the landscape as sufficient habitat for all species but really this is only appropriate habitat for a select number of species.  This also leaves no room for species to travel from one place to another.  On this rapidly increasing disturbed landscape we have created across southern Ontario, this often leaves one place for all other species to fend for themselves. Roadside edges.

image of indian hemp (Apocynum cannabinum
A visitor stopping for some nectar at an Apocynum cannabinum (Indian Hemp) in a moist unmowed roadside edge in Halton Region, ON

Ditches and the sloped grades of Highways and roadsides can provide a space for some of the native flora and fauna, not encompassed in forested areas, to live. It may not be ideal, but in some cases, it is the only place in an area species can find a suitable place to live.  So that seems great, we have some semi-suitable habitat for these displaced species, right? Well unfortunately it doesn’t stop there. We don’t let these spaces remain as places for native flora and fauna to grow. We trim them, mow them, dig them out, plant them with non-native lawn grasses to keep them ‘neat and tidy’.  We make it tough for these species to remain and reproduce and the conditions we provide favour non-native and invasive species if any.  We create spaces devoid of life for the sake of this ‘neat and tidy’ aesthetic which we try and maintain not even usually for ourselves, but more often for the fact of “What would the neighbours think?”. I see it and I hear it quite frequently.  It is tough to be the first one to break the norm but usually soon after this norm is broken most tend to follow suit either thinking the same thing all along or soon convinced it’s the right thing to do.

image of Michigan Lily (Lilium michiganense)
Lilium michiganense (Michigan Lily) in a moist roadside edge Norfolk country, ON. the Monarch (Danaus plexippus), Great Spangled Fritillary (Speyeria cybele), Spicebush Swallowtail (Papilio troilus), hummingbirds, and some bee species can be seen visiting the flowers for nectar. This species is becoming increasingly uncommon due to loss of habitat and population fragmentation.

We Must Take Action To Preserve Habitat Along Roadside Edges

Unfortunately, it doesn’t stop with the homeowners’ efforts to provide and preserve habitat along roadside edges of their own property.  In the last number of years’ counties and municipalities have been mowing, trimming, and digging roadsides more frequently.  There is the understanding that this is just what municipalities need to do to maintain roadsides, but much of this work can be counter productive. Many of the woody plants being trimmed are frequently trimmed improperly leading to potential for disease and a rapid regrowth of weakly attached stems which extend closer to the road and become more likely to break and fall off. For shrubby material, being completely cut off removes slower growing flowering type growth and encourages stronger quicker vegetative growth typically extending closer to the road then it did before.

For many of the invasive plants which now dominate our ditches and road edges, trimming typically only encourages their spread while unfortunately for many of their native counterparts this action of repeated cutting prevents the plant from reproducing. In many cases this gives invasive plants the opportunity to replace native species in these spaces. Proper invasive species control involves complete removal or chemical control of a species, anything less and growth is only encouraged.

image of Wild Blue Phlox (Phlox divaricata)
Phlox divaricata (Wild Blue Phlox) found along a shaded roadside edge Norfolk County, ON. Spring nectar source for hummingbirds and butterflies.

We have recognized in recent years that many pollinator populations are on the decline.  Keeping roadways trimmed eliminates the much need food supply pit stop to get pollinators from one location to the next. For pollinators who live permanently in an area trimming can suddenly eliminate most of their local food supply where they have decided to call home and it can be difficult or sometimes impossible for them to pick up and relocate.

If the goal is to protect the roadways, we are seemingly spending more taxpayer dollars doing extra repeated work trying to maintain road edges as clean tidy places at the same time doing more damage to our local flora and fauna.  Municipalities perform the functions they feel their patrons need and want. It is up to the people to let their municipalities know their views on these topics if we want things to change.

image of smooth serviceberry (Amelanchier laevis)
Amelanchier laevis (Smooth Serviceberry) a species primarily found along woodland and roadside edges. These are important places for species such as this which flower and fruit best here, and so best reproduce here. Serviceberries are also an early spring nectar source for bees

Increase Roadside Habitat Through Improved Practices

We have made it tough for our native flora and fauna in our developed world.  Hopefully one day we can increase habitat along roadsides by cutting less, removing more invasives, and planting back native species for the sake of the plants, we ourselves and wildlife rely on.  Imagine our extensive roadsides covered with native wildflowers buzzing with bees and butterflies.  No matter the conditions there is probably a native plant that will grow there. If roadsides were covered with our native flora and fauna maybe that trip to and from work may even become slightly less rushed. One day I hope we can change our perception of ditches and roadside places to be that of a place where native species can grow and provide habitat, living alongside us in peace.

The Importance of Roadside Habitat