Christine Roberts and Marcus Maddalena at George G. Newton Nature Reserve © Kirsten Dahl
Volunteering as a nature reserve steward is a rewarding experience with many benefits, such as the satisfaction of helping preserve natural habitat. That may include removal of invasive plants that outcompete native species and reduce biodiversity.
Huron Bruce Nature (HBN) has cared for the George G Newton Nature Reserve since 1996 creating and maintaining trails and working with partners to return former farmland to a natural state. In addition to regular upkeep, each year HBN organizes several work parties to remove invasive plant species.
Focus on Invasive Species: Garlic Mustard and European Buckthorn
Garlic mustard is a fast-spreading, invasive herb brought to Canada from Europe in the early 1800s. It is a biennial plant which, in the second year, produces flowers and abundant seeds that are easily spread by humans and animals and can remain viable for many years. It releases chemicals in the soil that disrupt natural processes and deter other plants from growing.
Common or European buckthorn is a highly invasive shrub or small tree that was introduced as an ornamental species in the late 1800s. It grows quickly to form dense thickets under which few plants can grow. Birds and animals eat the berries and spread seeds but it’s not considered a nutritious food source.
Several areas of the George G. Newton Reserve are heavily infested by both garlic mustard and buckthorn but with limited manpower, the club focuses on particular sections and experiments with control strategies.
Each spring HBN members concentrate on hand pulling garlic mustard at the entrance with particular attention to removing plants close to the trail to reduce the risk of spreading seeds deeper in the property in the treads of footwear. A second area of concern is a creek bank that supports a variety of native ephemerals and perennials.
Farther along the main trail are the remains of a barn foundation; an area completely overrun by garlic mustard. For the past few years this section is mowed using string trimmers to deny the plant the opportunity to produce flowers and seeds.
Buckthorn removal is tackled in the fall when the plant is easier to identify because it retains its leaves longer than native species. Armed with extractigators, a heavy pulling tool for woody plants, HBN members pull small to medium-sized trees and pile them on fallen logs to dry.
From 2023 to 2024 an estimated 1500 square feet of forest was cleared of buckthorn.
Positive Signs
When the garlic mustard work party returned May 2, 2025 they were surprised by the scarcity of mature plants in the targeted areas and in fact, a second work day was deemed unnecessary.
A subsequent visit revealed the presence of many first-year plants, and the club understands that it will need to continue pulling for years to come. However, in the near term it’s an encouraging sign that consistent effort over time seems to be yielding results. For the present the absence of new plants adding to the seedbank is regarded as a success.
This fall Nature Reserves staff will work alongside HBN members in its ongoing fight to control buckthorn. Larger buckthorn trees will be cut and the stumps chemically treated while previously cleared areas will be expanded and planted with native shrubs to increase biodiversity and improve the overall health of the forest.
The war on invasive plants in the George G. Newton Reserve is far from won but incremental victories with supportive allies like the Nature Reserves team helps maintain the resolve of the Huron Bruce Nature stewards.
Christine Roberts is a retired elementary school teacher. She is the president of Huron Bruce Nature and a steward of the George G Newton Nature Reserve. She is heavily involved in habitat gardening and native plant education in her home area of southern Bruce County.
