Invasive plants have no natural predators such as insects or disease in their new land, and they spread quickly across the landscape, competing with native plants for resources and often offering little value to wildlife. In North America, some invasive shrubs include European buckthorn (Rhamnus cathartica), European barberry (Berberis vulgaris) and several species of honeysuckle (Lonicera spp.) The conscientious gardener will work to remove invasive shrubs and other exotic plants from her garden or woodlot, although it may take several years and multiple attempts to be successful.
Pull young saplings in the spring. They will come up more easily and cleanly when the ground is soft and wet.
Cut larger shrubs or small trees with pruners or a hand saw in the late summer or autumn. Making multiple cuts over a period of time—such as cutting the tree down to two feet, then a week later cutting it down to one foot, then a week after that cutting it down to the ground—will weaken the shrub and hasten its demise.
Cover the stump with a tin can, such as an old coffee can, to prevent sunlight from reaching the plant. Alternately, you can cover the stumps with heavy-duty black plastic, weighted down with rocks or bricks.
For large infestations where it is not practical to cover every stump, paint the freshly cut stumps with a 20 to 50 percent solution of glyphosate herbicide, such as Round-up or Rodeo. These herbicides will kill other plants indiscriminately, so apply the chemicals carefully and always follow package instructions to the letter. Herbicides are best applied in the fall, when the shrubs are sending nutrients down to their root systems.
Continue to pull any saplings that emerge in the spring. Some invasive shrubs seeds may remain viable in the ground for up to five years.
Plant native shrubs in their place to provide food and shelter to local wildlife and shade out any sprouting invasives. Some shrubs that are native to North America include serviceberry (Amelanchier spp.), ninebark (Physocarpus opulifolius), New Jersey tea (Ceanothus americanus) and American hazelnut (Corylus Americana).