Got Knotweed? New OSU publication offers solutions.

Note, this is a reposted press release by Judy Scott, OSU Extension and Experiment Station Communications. And yes, this is my publication listed below so if you have questions, please contact me directly.

Giant knotweed spreads in a coastal community in Oregon.

Giant knotweed spreads in a coastal community in Oregon. Photo by R. Emanuel, OSU.

If ever a case needs to be made against introducing non-native plants to a new area, “woody knotweed” says it all. Like a sci-fi beast from outer space, woody knotweed seemingly wants to take over the Earth.

Imagine a weed that you can’t pull, cut or mow because you’ll encourage denser new growth.

Woody knotweed reproduces itself readily from small pieces of its own roots and stems and can contaminate the soil in which it grows. Knotweed-infested soil is considered a hazardous material in the United Kingdom.

A new Oregon State University Extension publication called “Biology and Management of Knotweeds in Oregon: A Guide for Gardeners and Small-Acreage Landowners” explains that the plant cannot be reasonably managed by non-chemical means. The publication is online and free of charge at Continue reading

Don't Move a Mussel in the PNW!

Just last month, Oregon Department of Fish and Wildlife inspectors discovered zebra mussels attached to a Michigan-based recreational boat arriving in Oregon at the Ashland Port of Entry. This was a strong wake-up call that the devastating mussels are on their way. It will only take one boat and one organism to infest Oregon waters.

US Fish and Wildlife Service have produced this video for helping show how easy it is to spread the mussels and how easy it is to prevent that spread into our state’s precious waterways.

To learn more about zebra and quagga mussels and programs aimed to prevent and detect their invasion, visit:

Watershed health is a gardener’s responsibility

Gardens can be both good and bad for watershed health. Photo: R. Emanuel.

Gardens can be both good and bad for watershed health. Photo: R. Emanuel.

Gardeners can have a huge impact on local watershed health. As hundreds, thousands and eventually millions of them influence the land use, inputs, water use and runoff patterns from their home landscapes, they shape the water quality of a watershed. Even little actions add up in a watershed.

Below are some resources I’ve drawn together for OSU Master Gardener trainings I’m delivering around the state this winter and spring. Hopefully others will find them useful too.

WaterWise Gardening Multimedia Presentation:

WaterWise ™ Gardening:

Surfrider Foundation Ocean Friendly Gardens:

Oregon Rain Garden Guide:

OSU Watershed Education Team:

Oregon Stormwater Solutions:

Protecting Water from Non-point Source Pollution:

Puget Sound Partnership (non-point source pollution):

Weeds and Climate Change

Here’s a new twist on an new problem: climate change (or increased warmth and carbon dioxide associated with climate change) may increase weed growth too. One of the chief arguments that climate change isn’t such a bad thing after all–the Green Earth argument–is the logic that greenhouse conditions and CO2 will assist humans with greater food crop and forest yields. One of the best arguments against this logic are that our crops (and forests) are not adapted to take advantage of the increased or decreased precipitation patterns–at least not where they are today. But it does appear that increased CO2 could be very good for weeds at least! For details, read the Weed Science Society of America press release posted below:

Knotweed on the Little N. Fork, Wilson River, Tillamook. Photo by R. Emanuel, OSU(LAWRENCE, Kansas) — Is global warming fueling a new generation of more aggressive weeds? According to recent research, the answer may be yes.

One of the major characteristics of a warming planet is an increase in the amount of carbon dioxide in the atmosphere. Rising carbon dioxide has been shown to help vegetable and grain crops grow more quickly, become more drought-resistant and produce potentially higher yields. Unfortunately, though, the impact of rising carbon dioxide seems to be far more pronounced in the weeds that compete with crops than in the crops themselves.

“Weeds are survivors,” said Lee Van Wychen, director of science policy for the Weed Science Society of America. “They can fill various niches and thrive under a wide range of conditions. While we have about 45 major crops in the U.S., there are more than 400 species of different weeds associated with those crops. There is always another weed species ready to become a major competitor with a crop if growing conditions change, such as an increase in carbon dioxide levels.”

The impact of rising carbon dioxide levels on weeds can be striking. In a study conducted by Dr. Lewis Ziska of the U.S. Department of Agriculture’s Agricultural Research Service, weeds grown under urban conditions of warmer temperatures and more carbon dioxide – conditions anticipated for the rest of the world in 50 years – grew to four times the height of those in a country plot 40 miles outside the city, where carbon dioxide and temperature reflected background conditions.

So what if there are a few more weeds? Well, Ziska’s research shows that common ragweed plants exposed to higher levels of carbon dioxide dramatically increased the amount of pollen they produced. A doubling in carbon dioxide led to a quadrupling of pollen. Some people are allergic to ragweed pollen, resulting in the “hay fever” response, including sneezing and watery eyes. Additional work by Ziska also suggests that even recent increases in carbon dioxide during the last 50 years may have led to bigger poison ivy plants with a more virulent form of the oil that causes people to break out in a rash.

“As the climate and carbon dioxide levels change, we can no longer assume the weed control strategies we used in the past will continue to work,” Ziska said. “Not only are some of the nation’s most invasive weeds spreading, but they are becoming more difficult and costly to control. Understanding the impact of increasing carbon dioxide on weed control is still in its infancy. While researchers explore new approaches, we will need to mix and match the strategies currently available.”

About the Weed Science Society of America

The Weed Science Society of America, a nonprofit professional society, was founded in 1956 to encourage and promote the development of knowledge concerning weeds and their impact on the environment. The Weed Science Society of America promotes research, education and extension outreach activities related to weeds, provides science-based information to the public and policy makers, and fosters awareness of weeds and their impacts on managed and natural ecosystems. For more information, visit

Post-Storm: Alive and Kicking

GOES IR, Monday 6:36 PM, Image courtesy of the National Weather Service.

This is just a quick update now that I can ford the flood waters and debris to get to the office, and have steady Internet connectivity. More news will come as we dig out and have more time to devote to these luxuries.

It’s been a wild ride here on the North Coast as those of you who have access to news can follow. Suprisingly, my family, neighbors, local coworkers, and I have been in what could be described as a news blackout due to the power outages, cable failures and just the fact that we’ve had more to do than keep up with the news. Rather than find out what’s going on in the region or even up the road, my neighbors and I been trying to secure sections of a roof, a barn, or fences, clear off the downed trees everywhere, and keep our families warm, dry and safe. As day 3 of no power, we hope that we’re through the worst of it. But progress will be extremely slow.

Highlights at this point (Wednesday, 12/5/07, 12:00 PM) (from South to North):

  • Nestucca River has dropped from a high of 20.5 feet on Tuesday (1.5 feet higher than 1996 flood of record);
  • the Trask River crested on Tuesday at 20.75 feet (4.25 feet above flood stage and 2.75 feet above 1996);
  • the Wilson River crested on Monday at 20.45 feet (above flood stage of 12.00 feet and 1 foot above 1996) and is currently at about 15 feet;
  • flooding on the Nehalem River has isolated the North end of Tillamook County and seriously flooded Vernonia in Clatsop County;
  • Foss Creek flooded at 24 feet (twice its bankful stage);
  • the Necanicum River at Sea Side was moderately flooded as of Monday but no new information is available;
  • Clatsop County is still largely without power and sections without water or sewer;
  • Tillamook County is still largely without power and significant sections are without water or sewer service, but schools and public life have restarted.

Here are three resources that have more information than I do (ironic given that my county clocked the highest winds), largely because we are so cut off due to communications and power failures:

I will update this blog as I can in the coming days. Hopefully with better and more news. Expect pictures soon.