I wrote the piece that follows while still a horticulturist working for Portland Parks about 20 years ago. It remains largely in its original form with a few additions, corrections and updates. Both plants are still under addressed in the landscape today. While employed I maintained my license as a public applicator of pesticides, a job requirement. I no longer have one, nor do I have a consultant’s license. In many cases herbicides can be an essential part of an effective strategy for the control of an established population of invasive plants. Invasive plants, like these, which are listed on your State’s Noxious Weed List, are there because of the the threat they pose to the environment and their capacity to infect and dominate a landscape, any landscape, across our region. In more than a few cases manual and mechanical methods of control alone are insufficient to ‘control’ the invasion and sole reliance on them will assure the failure of the establishment of a desirable landscape on a site. Herbicide use is thus justified. Large scale restoration projects are often dependent upon it. On a smaller residential property, with commitment and persistence, a homeowner may be successful, but even then they need to understand that there will be a continuing and significant threat of reinfection from surrounding properties, via birds carrying the fruit of Ivies and wind blown seed from Clematis. For some species, especially when the scale of the invasion and property are larger, its use may be essential. For many weeds this herbicide ‘threshold’ is very low before its use is a requirement. In this way scale works for homeowners as their properties and problems are smaller. Too often though properties are neglected and then the buyer inherits a serious problem. Using any herbicide will always have potential adverse effects on the environment, so if you choose to use it make sure you do so effectively. If you choose to use any of my herbicide suggestions, you are on your own. Do your research, understand your problem, to assure that your actions are effective, safe and responsible.
Getting Down to it: Your Viney Culprit is Probably Hedera hibernica, Irish Ivy, or More Rarely H. colchicum
English Ivy, a friend and co-worker announced early on in a then still continuing series of work meetings concerned with various issues of invasive plants, has been a kind of “anti-poster child” for those working in the regional conservation and restoration field. Its spread and control has been the subject of innumerable meetings, proposals and actions both fruitful and not. Eradication is no longer considered a realistic goal by many. The focus, rather, is on limiting its spread and control. Like other exotic invaders and introduced guests now run amok, from diseases to various shellfish and weeds, once a particularly well adapted species establishes a viable population base, it becomes a part of the disturbed novel landscape…it’s here and we’re going to have to figure out how to deal with it. This has always been the way of the world. The difference today is the rapidity with which these changes have been introduced through trade, the peripatetic travels of man (Man in the generic sense) and our never ending appetite for the consumption and disruption of land.