Category Archives: Invasive Plants

Controlling English Ivy and Clematis vitalba in the Landscape

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.

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Bocconia frutescens: Choice Tender Garden Plant or Invasive?

 

Bocconia frutescens with its inflorescence of single seeded fruit, one of the ‘woody’ Poppies that comprise the genus.  Macleaya cordata, from the same family, has a similar look, though topping out at around 8′ and is herbaceous in habit dying to the ground each winter.  Another Wiki picture of Bocconia f.  growing in Hawaii’ where it has escaped cultivation and threatens the few remaining native landscapes, particularly historically dry and mesic forests.

The title’s question isn’t something we in the Pacific Northwest need to worry about.  It will take an awful lot of global warming to make this plant cold hardy here and that may be part of its enticement!  I chose this from Jimi Blake’s list…because I am a sucker for cool foliage.  Sometimes called the Mexican Tree Poppy this is a Poppy, a member of the family Papaveraceae, a family currently containing 42 genera and 775 species, which is within the the ancient order, the Ranunculales, an order that includes some of the earliest of the ‘modern’ Eudicots to evolve.  This doesn’t mean that this species of Bocconia was around at the beginning of ‘time’, or even of this order, just that it comes from that particular genetic line, a line that has been traced back to its beginning, millions of years ago.  Recall that every plant, every organism is in ‘process’, that given the appropriate supporting conditions, consistent over time, will keep reproducing, generation after generation…and, that given the appropriate inducements, of consistent, changed conditions, different from those today, will work to adapt to them, each generation ‘responding’, those better adapted, surviving and reproducing, altering the species and, perhaps even becoming, producing, a new one.  One of the characteristics of this family and order, having arisen in a time when genetics and characteristics of plants were less strictly defined, is a wider range of physical or morphological variation than you might expect, which is evident when you look at the flowers of the many diverse species within these genera, this family and order…Bocconia frutescens’ small flowers looking very unlike those we would commonly think of when we picture a Poppy. Continue reading

The Lower Deschutes River: the Incursion of Invasive Plants and our Failure to Responsibly Maintain Native Plant Communities

This picture should give anyone more than enough reason to visit here, the Deschutes sliding out its mouth into the Columbia with the Washington side of the Gorge in the distance, the low angled early evening sun illuminating everything sharply.

 

[As I go over this post yet again, July 21, the 80,000 acre Substation Fire is still burning across canyon and wheat country here.  Included in the blaze are the 20 miles of the Lower Deschutes canyon down to the campground at the confluence with the Columbia.  Much of this burned down to within 2′ or 3′ of the riverbank including the historic Harris Ranch buildings.  So, when you look at all of these pictures, with the exceptions of where the fire hopped and skipped, everything is charred.  The Oregon Wildlife Federation, formed in the 1980’s to purchase and protect this portion of the canyon, has stepped up with $100,000 to help the area recover.  It will take considerably more especially if there is any intention of making headway regarding the spreading invasives problem.]

[Now, another 2 weeks later more massive fires continue to burn across the dried up West that has just experienced another record breaking month of heat, while the president goes on ‘bleating’ and blaming it on our ‘bad’ environmental laws and all of the water we’re diverting into the ocean!  ‘F’ing! moron!]

The last time we came here was eight years ago in December.  My memory of then is much like the experience on this evening…only it was clear and cold.  The light was similar except that then the low angled sun was due to winter, with that season’s urgency, not a late Spring evening like this outing.  This time it is warm, camp is comfortable and nearby and the greens are still gathered around the river and the still moist draws and seeps.  On that day we’d gone to Hood River for my birthday, to get out of town and there was a break in the weather so we drove here to these trails at the mouth of the Deschutes, hiked along the river, returning on the upper springs trail.  Winter or summer, green only sticks around a little longer than we do, before it retreats…life is shier here, tough, but shy.  The starkness of this landscape should be read as a warning to visitors, this is no easy Eden.  Life is earned here or at least requires a strength, patience and frugality that many don’t have.  This is much the same for people as it is for wildlife and plants.   Them that don’t, can’t.  That’s why it may be surprising to some that such a place has a problem with exotic invaders.  What could possibly look on places such as this as ‘favored’?  Well, Central Asia, especially its Steppe, with its continental, cold and dry climate containing many species that see such a place as this as home, or even better, without the competitors they faced back there.  The temperature can swing widely here on any given day while the seasonal extremes can vary as much as 125ºF from high to low.  Relatively few plants can thrive in this.  The dry summers with their very limited and sporadic thunder showers, combined with the ‘wet’ winters, total only 10″-12″ or so of precipitation, plus or minus, is another major limiting factor.  Of course, near the river, the moisture problem is moderated  and a broader range of invasives can find a ‘foothold’.  We, as a people, have ‘brought’ these weeds here with us in our travels, often as a result of our commerce.  Those that have made it here are spreading.  Too many prosper. Continue reading