Self-Guided Walk: Ecological restoration in the Don

We enjoy thinking that our walks in Toronto’s natural areas are visits to remnants of wilderness that have endured centuries of city-building. However, after 200 years of growth, there is virtually no place in our city that’s not been transformed time and time again. Much of the natural heritage you enjoy is actually the result of ecological restoration efforts by people! On this 3.3km circular walk you’ll discover how the industrial legacy of the Don Valley has been transformed into natural heritage by visiting Beechwood Wetland, Sun Valley, and Cottonwood Flats.

Distance: 3.3km, circular route
Difficulty: Easy (paved path, mostly flat)
Washrooms: None

Walk route contributed by TFN member, Jason Ramsay-Brown. All waypoint photos and descriptions by the same unless otherwise attributed.

Walk start & end point

Walk starts outside of the Toronto Police Dog Services training facility at 44 Beechwood Drive. There is a small, free, public parking lot at the trail head. To access via TTC, take the 100 Flemingdon Park bus north from Broadview Station and exit at O’Connor Dr & Hopedale Ave. Walk down Beechwood Dr to the parking lot (about 10 minutes, very steep hill with no sidewalk.)

Waypoint #1Black walnut grove

Black walnuts (Juglans nigra) are an ecologically important native species, serving as larval host for many Lepidoptera (like the luna moth and banded hairstreak butterfly) and providing nutrient-rich nuts that feed a diversity of rodents. This grove of trees were planted here by the Toronto and Region Conservation Authority (TRCA) during the early 1990s.

Black walnut is “allelopathic” – they release a compound called juglone from their roots that inhibits the growth of other species of plants. Birch and pines are particularly sensitive to juglone, which explains why you won’t usually find them growing too close to a black walnut! Dog-strangling vine (DSV), an invasive species of great concern here in the Don Valley, is somewhat juglone-intolerant. This slope has been abundantly invaded by DSV, but if you look carefully you’ll see how these plants do not grow in the soil directly over the roots of these walnuts.

Waypoint #2Invasive phragmites

Dubbed “Canada’s worst invasive species,” this towering perennial grass, phragmites australis subsp. australis (better known as “phrag”), can be found throughout the Don Valley. 

Phrag accepts little competition, releasing toxins in to the soil that severely impacts the growth of other plants. It spreads aggressively via a rapidly growing network of roots and rhizomes which are able to shoot up new reeds every dozen centimeters or so. The resulting monoculture is a virtual green desert, providing little to no habitat value to the vast majority of visiting creatures.

Phrag also severely impacts general wetland function by lower surrounding water levels, altering water cycles, and trapping the nutrients it extracts from the mud in its rigid, fibrous stalks which take much longer to decay than most of our native plants would.

The combined impact of all of these effects is nothing short of catastrophic. Phrag removal in this area is an ongoing project by local stewards, but without the use of pesticides or heavy machinery, removal is painstakingly done reed-by-reed, using hand tools to cut each stalk a few centimeters under the soil surface. Using this method it is estimated it will take at least a decade before this patch of phrag is under control.

Waypoint #3Beechwood Wetlands

Heading south from here, the wooden fencing along the eastern side of the Lower Don Recreational Trail protects the Beechwood Wetland, one of the most remarkable ecological restoration projects in the whole of the Don Valley.

By the end of the previous century, decades of sustained industry and urban development in the area had left behind contaminated soil, mountains of refuse and a forest of invasive species, most notably Japanese knotweed (Fallopia japonica) which then accounted for nearly half of the biomass along this section of trail.

In 2002, through the combined efforts of several groups including the Federation of Ontario Naturalists, the Task Force to Bring Back the Don, the TRCA and the City of Toronto, heavy machinery was used to radically alter the landscape and transform a runoff ditch from the Don Valley Parkway in to what is now a fully-functional wetland.

These efforts were remarkably successful. Beechwood Wetlands is now frequented by an abundance of native animals including snapping turtles, green frogs, American toads, great blue heron, downy woodpeckers, and countless other species. Take some time to study the landscape and you’ll now spot amazing examples of purple-flowering raspberry, staghorn sumac, witch hazel, bur oak, cup plants, and over a hundred other native species thriving here.

Waypoint #4Beechwood Stewardship

Guarded by the wooden fencing found along this portion of the Lower Don Recreational Trail, the Beechwood Wetland is a constructed natural feature, painstakingly brought in to existence in 2002/2003. Had efforts stopped then, however, there is little question this amazing place would now be overrun by all manner of invasive species. A careful look around, however, will reveal that an amazing wealth of native biodiversity calls this place home, and for that we have the Beechwood Wetlands Stewardship Team to thank.

For the last couple of decades, citizen volunteers with the City of Toronto’s Community Stewardship Program have met here once a week during the warmer months. These stewards patrol the area, removing invasive species, planting new natives, cleaning up illegal dumping, and generally taking care of nature here at Beechwood.

Participation in the Community Stewardship Program is open to all Torontonians! For more information see:

Waypoint #5“Bill the Cat”

Photo courtesy John Routh

At 150+ years old, this bur oak (Quercus macrocarpa) is one of the oldest trees in this section of the Don Valley. Some folks spot the face of a much-loved Bloom County character in the bark patterns half-way up its trunk, earning it the moniker “Bill the Cat”.

Oaks are generally held to be one of the most ecologically important tree species in our local forests, said to sustain several hundred different species of wildlife and to contribute greatly to soil quality. This particular tree protects a genetic legacy all but lost throughout the valley, playing parent to seedlings uniquely suited to Toronto thanks to almost 10,000 years of evolution.

Waypoint #6Sun Valley – the old Leaside dump

The parcel of land in front of you, encircled by hardened trail, is not quite the natural feature you might imagine – below it lurks decades of city garbage some twenty-five metres deep in spots!

In the late 1930s, the then Town of Leaside purchased an exhausted clay quarry from Sir Henry Pellatt, the builder of Casa Loma. The giant hole in the ground was exactly what Leaside was looking for to deal with the mountains of garbage being produced by the quickly growing town. In the years just before its closure in May, 1965, the dump was said to be receiving over a hundred truckloads of industrial waste and sanitary landfill each day. After its closure, the site continued to accept ash from the Commissioners Street incinerator which was used to bury the dumping pit before finally being capped with cleanfill and topsoil and left to renaturalize.

Over the decades since, numerous plantings have been conducted on and around the area by the TRCA and City of Toronto. Little, if any, evidence of Sun Valley’s depressing past is obvious to visitors today.

Waypoint #72013 Planting

Much of the renaturalization in and around Sun Valley was completed by the hard work of citizen volunteers, and this particular spot is a great example!

On May 25, 2013, roughly 20 Torontonians of all ages, led by City of Toronto Forestry Staff, arrived here at 10am to sink over 100 trees and shrubs in to the soil. Species planted included elderberry, white pine, serviceberry, bur oak, and purple-flowering raspberry. Digging was extremely difficult as much of the main planting area was atop a buried asphalt roadway that presumably once serviced the Town of Leaside dump. Regardless, thanks to the perseverance of volunteers and staff alike, all stock was planted in under two hours!

The City continues to hold public tree planting & stewardship events throughout Toronto. If you’d like to try your hand at renaturalizing a bit of our city, check out:

Waypoint #8Welcome to Cottonwood Flats

If you watched local news in January of 1999, this area likely seems somewhat familiar to you – once one of Toronto’s most active emergency snow dump sites, reporters did a fair share of “on location” shots from here in the days that followed mayor Mel Lastman’s controversial enlistment of the Canadian army to help dig Toronto out of a pretty brutal winter.

Serving as a snow dump was only one role of many that Cottonwood Flats has played over years. In the early nineteenth century, it was the stomping grounds of Parshall Terry, who served in the first parliament of Upper Canada, and built his home nearby. In the mid-20th century, an insulation factory operated on the site. The beauty that now surrounds you didn’t exist until 2014.

Starting in 2009, the City of Toronto, TRCA, Task Force to Bring Back the Don, and Schollen and Company collaborated to renaturalize this once-abused area. The final restoration plan required all manner of heavy equipment, plant stock, patience, and months of hard labour. The end result is this small parcel of what ecologists would call “Exotic Forb Old Field Meadow”, and home to at least one-hundred species of vascular plants, roughly 30% of which are native species.

Waypoint #9Cottonwood Flats Songbird Meadow

Jokingly dubbed Toronto’s Worst Off-Leash Area, you won’t find a single gate in the continuous fencing that surrounds this one-acre bit of nature. This is by design, as the Cottonwood Flats Songbird Meadow was designed to serve as protected habitat for ground-nesting birds!

The enormous damage wrought by off-leash dogs may be the most under-estimated threat to nature in Toronto. Their uncontrolled movements are interpreted as direct and immediate threats my most wildlife, causing them to abandon feeding, flee nests, interrupt mating, and similar such behaviors. Their “bathroom breaks” are toxic to many plants, and with repeated disposal can kill saplings and maturing trees in a matter of months. While a single dog is, perhaps, not much of a threat all on its own, records indicate that Cottonwood Flats is visited by as many as 20 dogs an hour, the majority of which are off-leash. Without this fencing, the likelihood of any ground-nesters feeling safe long-enough to hatch a new generation here would be best estimated at near zero.

While ground-nesters haven’t exactly flocked here over the years, dozens of different species of birds make routine use of the Songbird Meadow, most plentifully: American robins, red-winged blackbirds, tree swallows, song sparrows, American goldfinch, and Baltimore orioles.

Waypoint #10CFMP Bird Circle Location

You are standing at the centre of the “CFMP Bird Circle”, an important location in an ongoing citizen science initiative, the Cottonwood Flats Monitoring Project (CFMP).

Started in 2017, CFMP is a partnership between the Toronto Field Naturalists (TFN) and the City of Toronto’s Natural Environment and Community Programs (NECP) section of Urban Forestry. Each year, TFN conducts two vegetation surveys and six site monitoring sessions at the Flats. Data collected is used by NECP to determine plant and animal biodiversity in the area and assess overall trends in species richness and abundance. Further, TFN uses the data to provide ecological enhancement recommendations that inform the City of Toronto’s ongoing management of the site, including invasive species control, species introduction, and habitat feature creation/maintenance.

Each monitoring session starts with a 10 minute observation period of the 50 meter radius of landscape that surrounds you. The majority of CFMP bird sightings are logged from this location, so hang out for a while and see what you discover!

Waypoint #11Slab City

Photo courtesy David Wallace Barr

This collection of concrete slabs is believed to have been dumped here around the 1950s, back when Cottonwood Flats was home to an insultation factory. When ecological restoration efforts began on the site in 2014, there was some discussion about hauling it all away. Instead, the slabs were stabilized and protruding rebar removed in hopes that it might serve as home or hibernaculum for local wildlife.

Nowadays, eastern cottontail rabbits are often found to warren in the slabs. Gartner snakes are spotted with some frequency. Pupa, chrysalis and cocoons have been discovered clinging to overhangs and nestled in crevices. There’s even evidence that coyotes sometimes make use of the site over the winter months!

Take a rest, sit for a while … who knows what might just poke its head out!

Waypoint #12Cottonwood Flats Wetland

Map graphic copyright 2010, Schollen and Company

The wetland cells and features in this area of the Flats were constructed in 2019/2020 after some four years of planning and study. The vision of a wetland here, however, predates these efforts by almost a decade.

The decommissioning of the emergency snow dump that once occupied this site opened up Cottonwood Flats for a variety of potential renaturalization projects. In 2010, Schollen and Company, in collaboration with the City of Toronto, TRCA, and Task Force to Bring Back the Don, developed a Landscape Concept Plan that, if built, would have seen most of the Flats transformed in to wetland!

The plan suggested that water from the Don enter the site via a small inlet located between the Metrolinx tracks and the bridge to Sun Valley at the north end of the Flats. This water would have flowed through a meandering trench surrounded by floodplain and small wetland cells that criss-crossed the area between the Don and what is now the eastern-most section of hardened trail, before emptying back in to the Don through an outflow channel located pretty much where you’re standing now. A secondary wetland would have also been constructed downstream from the outflow a bit, ending at the Metrolinx crossing at the south end of the site. This secondary wetland is, of course, the section of wetland actually constructed in 2019/2020.

You might be wondering why the original plan was shelved in favour of the meadow-like habitat that rose in its place instead. Budget, naturally, was a significant issue. A second, but equally show-stopping reason was consultation with the local community: many felt that a wetland would restrict their recreational use of the space for cycling, dog-walking, etc.

Waypoint #13Willows

The pussy willow (salix discolor) and peachleaf willow (salix amygdaloides) found here might be the two most important trees in all of Cottonwood Flats during the month of April. As the nearby cottonwoods are only starting to bud, these willows are already in full bloom, their nectar-rich flowers serving as a vital food source for early spring butterflies and other native pollinators!

To illustrate, a study of the pussy willow here, conducted by the Toronto Field Naturalists in April, 2018, documented visitation by some 52 butterflies of three different species in a single hour! More generally, over 450 species of moths & butterflies are said to depend exclusively on willows as hosts for their caterpillars. As food source and host plant, few of our native trees are as ecologically critical as the willow.

Waypoint #14Relic kiln from Middle Mill

This old stone kiln marks the original location of the Taylor Brothers “Middle Mill” pulp paper production facility. Founded in 1858, it was last of three mills built by the Taylor family along the Don River.

The Middle Mill continued operations under 1901 then bankruptcy transferred ownership to Mr. Robert Davies. By 1909, Davies’ had modernized the mill extensively, and his Don Valley Paper Company Limited was considered a model enterprise of the time. The business switch hands again in 1932 becoming the Howard Smith Paper Mills Company. In 1961 it was sold to Domtar who eventually outgrew the facility, and sold the property to the Metropolitan Toronto and Region Conservation Authority (MTRCA) in 1989.

MTRCA demolished much of the facility, and spent years remediating the land from the abuses of its industrial past to make way for the nearby Beechwood Wetland, an outstanding example of ecological restoration in the Don Valley. This kiln, and some of the facilities of the Toronto Police Dog Services campus just north of here, are the only surviving remnants of this history today.

Getting away: If you arrived via TTC, walk back up Beechwood Dr to O’Connor Dr and catch the 100 Flemingdon Park bus south back to Broadview Station at the bus stop located on the south east corner of O’Connor Dr & Beechwood Dr.

Toronto Field Naturalists wishes to acknowledge this Land through which we walk. For thousands of years, the Land has been shared by the Wendat, the Haudenosaunee, and the Anishinaabe. Toronto is situated on the Land within the Toronto Purchase, Treaty 13, the traditional and treaty Lands of the Mississaugas of the Credit First Nation. This territory is also part of the Dish with One Spoon Wampum, a covenant agreement between Anishinaabeg, Haudenosaunee, Wendat peoples and allied nations to peaceably share the land and all its resources. Today, the Land is home to peoples of numerous nations. We are all grateful to have the opportunity to continue to care for and share the beauty of this Land.