Sandy Hillers work to create a Knotweed free zone in the park

John Cockburn and Brian Dewalt

Throughout the summer a dedicated band of Sandy Hillers has been working hard to rehabilitate the natural habitat along the banks of the Rideau. In addition to weeding the poorly maintained gardens at the foot of the Adàwe Crossing bridge, a principle focus of their efforts has been to contain the spread of the invasive plant, Japanese Knotweed, along the Rideau River path between Strathcona Park and the entry to Robinson Village. Knotweed, imported as an ornamental shrub in the 1800s, outcompetes native flora and eventually crowds out all other plants. The group, numbering about 20 people, is working under the auspices of the Tree and Greening Group of Action Sandy Hill. The Japanese Knotweed project was initiated by Bryan Dewalt, with valuable input from Marilyn Whitaker and other members of the Tree and Greening Group.

Photo John Cockburn

The high point of the effort took place during the sweltering August 26-27 weekend, when volunteers returned to areas from which they had earlier dug out or cut back Knotweed plants; and covered these patches with geotextile cloth and about 100 millimetres (four inches) of mulch. The aim is to smother the remaining rootstock in these areas and prevent it from re-growing. This will create a Knotweed-free zone in sensitive areas near the riverbank and public pathway, and provide a buffer against large Japanese Knotweed infestations still growing on steep upper slopes, farther from the river.

Volunteers will follow up by removing any Knotweed plants that sprout around the edges of these control zones, and by planting a variety of robust native plants nearby to increase local biodiversity. Next year the City has undertaken to replant the area with native trees and shrubs.

It has been a noble effort by the group, given both the time and physical effort from the volunteers, as well as the time involved for the leaders to deal with the organizational complexities of obtaining a grant from the City for the purchase of geotextile landscape fabric, mulch and other supplies. In addition to the City’s support, the group was grateful to receive discounts on fabric and mulch from suppliers, Ritchie Feed and Seed, and Greely Sand and Gravel.

Work continues throughout the fall. Interested volunteers can make contact through the Tree and Greening Group listing on the ASH website.

Gabrielle Dewalt, Jane McNamara, Michel Gauthier, Joelle Sanderson, Bryan Dewalt, Marilyn Whitaker, present but missing from photo are Rhéal Gauthier, Susan Young, Sabrina Mathews, John Cockburn.
Photo John Cockburn
Japanese Knotweed
Photo John Cockburn