Category Archives: Invasive Plants

Knapweeds in Redmond’s Dry Canyon and the Pursuit of a Healthy Landscape

Leave a reply

Redmond’s Dry Canyon looking south from the west rim on the Maple Street Bridge. The area in the immediate foreground burned this last summer.

If you garden, or maintain a landscape, you come to understand that not all weeds are the same. Each will have its own ‘strengths’, or perhaps you might call it ‘virulence’. Any particular weed, just like any other plant, will respond ‘positively’ to supportive growing conditions, conditions which often closely align with those which exist in its place of origin. Plant explorers and nursery growers are always looking for ‘new’ plants for landscape use. in a way, they have to walk a fine line. They must find plants, that with reasonable effort on the part of the gardener, can thrive across a range of conditions, unless they are looking for specialty plants, for narrow, niche, markets. The introduction of new plants must be somewhat measured, our enthusiasm tempered, because plants which are too adaptable, too vigorous, may possess the ability to escape our cultured gardens and find a place in the surrounding, uncultivated, landscape.

For Central Oregon, when we look beyond our regional natives, we must keep this in mind. Exotics from similar growing and climatic regions around the world offer both promise and threat. We want our plants to be successful, but not too. Sometimes through the process of trade, the movement of livestock and agricultural products, particularly aggressive species hitch a ride. A few weed seeds can be easy to miss. If they are aggressive enough and go unnoticed, a distinct possibility, it is likely that they wont be detected until a sizable local population asserts itself…and if no one is watching, that can be a fateful error. One group of plants, with many wonderful possibilities, also include species which can be exceedingly problematic here in Central Oregon, these are from regions sometimes referred to as Steppe. Continue reading →

On Weeds, Disruption and the Breaking of Native Plant Communities: Toward a More Informed Working Definition of Weeds

Leave a reply

The bottom land in Redmond’s Dry Canyon was used for decades as low quality pasture, the native community pretty much obliterated. Those areas with surface rock are more likely to retain more of the original plant community, although Cheatgrass has invaded much of those areas as well. The is looking southerly over one of the larger ‘pasture’ areas near the disc golf course. There is very little Cheatgrass through this section south of West Rim Park. It includes a few native seral species which typically occupy disturbed sites as a site transitions, including Gray Rabbitbrush you see here. Found in this area too is Secale cereale, Annual Rye, a non-native, which appears to have been planted along more formal paths to limit Cheatgrass spread(?).  Junipers are moving in. Sagebrush hasn’t yet.

It is commonly said that a weed is a plant out of place…and of course ‘we’ are the one’s who decide this. Some will try to argue that there are no weeds, that all plants belong and if we only left weeds alone landscapes would reach a balance on their own. If one’s time frame is long enough this may be the case, though this will take considerably longer than one of our lifetimes, and then there is our inability to actually leave landscapes on their own, or to at least consciously moderate our disturbance of them. Weeds are plants. They are not a separate classification of plants. They are plants removed from their places of origin and released into another where they have competitive advantages. Most people still simply tend to refer to plants they don’t like or want as weeds. These positions are at odds with one another. This leads to confusion and a lack of clarity, undermining any urgency to take action.

Weeds have become ‘personal’, their status a matter of ‘opinion’….A weed is a weed only if “I” agree that it is, or perhaps some ‘expert’, such as when agricultural scientist identify them as an economic threat to farms and label them as ‘noxious’. Without agreement and urgency there is a tendency to do nothing about them. Plants in general are attributed little intrinsic value. For many people they are just there. Native plants we vaguely understand as belonging to a place, but most people would be hard pressed to identify and name many at all. Quite different species are often lumped together, their relationships unnoticed. Natives are reduced to being ‘background’, their status reduced to decoration, attractive or not, a ‘space’ filler, perhaps a hinderance to what we would chose to do with a place. Continue reading →

Spruce Park, Redmond’s Newest Park and Our Neighbor: a horticultural critique

1 Reply

Redmond’s Spruce Park looking NNE from the SW corner toward Gray Butte and Smith Rock in the background. The border beds which follow much of the loop path are ‘native’ plantings according to the conceptual plan. It is common to claim that most of the plants are natives in designed natural areas, but native is not synonymous with ‘natural’. Although natives are used here concessions have been made including such plants as Echinacea purpurea ‘Pow Wow Wildberry’ and Rudbeckia ‘Goldsturm’. In a strict sense Ponderosa Pine aren’t native to this immediate locale either, they require more precipitation than we normally get and the Autumn Blaze Maples are a hybrid of two northeastern North American species.

A landscape, in nature, is a whole, functioning system, capable of perpetuating itself, through out the seasons and years, relying entirely on its own conditions and the cycling of energy and resources occurring on and within it. This is also the definition of a modern sustainable landscape. Ideally they require no inputs or energies supplied from offsite aside from the sun, precipitation and the normal cycling onsite of nutrients and water. A human made, contrived landscape, as all of those built by us today are, may be ‘judged’ by how well they function on ‘their own’, by how well they fit this ideal. Labor and outside inputs necessary to maintain a landscape are then indicators of how out of balance, how far from ‘ideal’ nature and genuine sustainability, a landscape is. A contrived landscape, which ignores the relationships integral to a healthy landscape community ‘demands’ more and more maintenance and support. Given its design and use, a landscape which ignores its site and relationship requirements will deteriorate from the intended design, losing to death component plants while gaining, increasingly, more unwanted available weed species. Design, conditions and use are essential to determine, in this sense, what a ‘good’ landscape is. Continue reading →

Controlling English Ivy and Clematis vitalba in the Landscape

Leave a reply

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.

All Ivies have a juvenile and mature phase. The juvenile leaves tend to be more angular, deeper lobed and smaller than the mature leaves. Wikipedia
Hedera hibernica with its more ’rounded’ mature leaves and fruit.

Continue reading →

Bocconia frutescens: Choice Tender Garden Plant or Invasive?

3 Replies

 

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

Leave a reply

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 →