Have you noticed this invasion yet?

The plant is the Glossy Buckthorn. It has become a real worry not just to landowners but to Kejimkujik National Park and National Historic Site, which is trying to have it removed the minute it appears. It got a jump on us, because we thought it was just more wild cherry trees growing and naively let them be. Now I am mowing and cutting the plants down.

McGill University's Canadian Biodiversity Project describes the Glossy Buckthorn as a native of Europe, imported to North America in the 1800s to be used for landscaping. Like many imported species, it has become naturalized and thrives, extending from Nova Scotia to Manitoba but concentrated in Ontario.

The plant was imported for hedgerows as early as 1850 in places like Wisconsin. It was first introduced in Canada in London, Ontario, in 1898; in Ottawa in 1899 and in Guelph in 1906, and spread from there. It was noticed growing wild in the St. Thomas area by 1950, in Toronto by 1953 and in the Georgian Bay area by 1968. By 1975 it was being recorded east of Ottawa, according to the McGill project.

It was first recorded at Kejimkujik National Park in 1980, possibly the fairly large plant that was identified again in 2004 near the entrance to the warden's compound. It began to spread. Efforts to eradicate it began seriously this year, with staff and volunteers cutting the plants, digging up the roots or pulling up the plants altogether. Darien Ure, Ecosystem Scientist at the park, told me that a couple of other Glossy Buckthorn plants had been identified in the park, and that they would be removed wherever they occur.

It grows in both wetland and upland habitats, inundating the edges of woodlands, fencerows, fields, prairies, swamps and bogs. You can recognize it by its shiny leaves and, at this time of year, its purplish-black berries.

Biologists consider the Glossy Buckthorn an aggressive and dangerous species. Because of the dense shade it produces, it kills off other species native to our woodlands. We've noticed, for example, that the alders we used to have at the bottom of our field are being squeezed out. The Glossy Buckthorn also plays host to a fungus that attacks oats and grasses.

It seems to be spread by starlings, robins and waxwings, which release the seeds through their droppings.

Controlling the Glossy Buckthorn is difficult. It won't survive on fields that are mowed regularly, but cutting them down around the edge of fields is problematic, because they sprout like mad when cut. Constant cutting tends to weaken the plant, but in a large area, that is not always possible.

Darien Ure has been dealing with the outbreak at the park. She said that one method of control is to pull the plants out of the soil using a device called the Weed Wrench, a tool that provides the leverage to pull the plant out (available from the Weed Wrench Company, in Oregon). She thought it had been used with some success by the Clean Annapolis River group.

The larger buckthorn plants require heavy equipment to remove them, or they can be cut off and the stumps treated with an herbicide.

Darien sent me a report from a group in London, Ontario, called ReForest London, which is a non-governmental organization working with trees and shrubs in the city. It sent a team of nine people to the city's parks to remove the plants and – to emphasize how difficult it is to remove it – set up a multi-year management plan.

In the first year, all seed-bearing plants are removed from the area being controlled. In the second and third year, all emerging seedlings are removed. Then native plants are reintroduced, to provide shade that retards the growth of the buckthorn. Thereafter, the area must be monitored to control immature plants.

The University of Maine suggests that cutting a ring through the bark of each plant will prevent resprouting, but that is impractical if there are thousands of plants. It also suggests mowing, repeated cutting, excavation or successive burning.

To me, that sounds like a major battle, and the reason I write this is to suggest that if the invasion is just beginning on a person's property, the owner should get to removing the plant right away. We, and many like us, have, on the other hand, our work cut out for us.

Tom Sheppard can be reached at twsheppard@gmail.com