 |
 |
|
KC Weed News - October 2007 (PDF Version for Printing) TOPICS BELOW
It’s hard to know where to start with this month’s weed. Himalayan blackberry is such a common sight in the Pacific Northwest that it is easy to overlook it when thinking about weeds. Blackberry is the one plant that everybody knows – most of us have eaten its berries, been pricked by its thorns, and struggled to keep it from overwhelming our backyards. It amazes people new to the area that it isn’t native to the Northwest. Personally, I find it almost frightening how an introduced plant could become so well-established in just a little over a hundred years. Have you heard the story behind Himalayan blackberry? In the 1880’s, California horticulturalist Luther Burbank started propagating a blackberry species he called the Himalaya Giant. He thought the seeds were from India but we now know that they were from an Armenian species. Indeed, he brought us the same blackberry that was being widely introduced to Europe starting about 1835. This blackberry variety quickly became the most frequently cultivated blackberry in Europe due to its large, sweet fruit and amazing growth. And, not surprisingly, the same thing happened in the United States. Dave Battey, local historian and horticulturalist from the Snoqualmie Valley, gave me this quote from the 1885 promotional literature about the Himalaya Giant: “A single cane may grow twenty feet – even fifty feet, in one season….Aggregate cane growth of a single plant in a single season may exceed 1,000 feet – one fifth of a mile. As for fruit production, the Himalayan far surpasses any blackberry ever known. A single bush may bear 200 pounds per season.” Dave writes that “After a decade of probation, the Himalayan took its place as the pre-eminent blackberry on the Pacific Coast….For several years the blackberry could not be propagated fast enough to meet the demands of the public.” In 1914, a horticulture book wrote that the Himalayan is “somewhat difficult to manage”, and the variety became much less popular over time. I have read that Himalayan blackberry is still used in developing new varieties of tasty berries, but that the pure species isn’t generally used due to the obvious difficulty in managing it. Of course, in terms of the impact on our landscape, the damage has already been done. This plant has no trouble propagating itself and continuing to expand and overwhelm new territory when given the opportunity. Even though it is clearly a widespread plant, you might ask whether Himalayan blackberry is really a serious problem or just an annoying pest with really tasty berries. It is often dismissed as a plant that simply takes advantage of disturbed areas, but there is concern among some ecologists that it is having a much more serious impact. An article by Sam Chan and Kathy Mass-Hebner points out that Himalayan blackberry lacks the deep, bank-stabilizing roots of native wetland and riparian species and that its presence often masks eroding stream beds and incised banks. In addition, they write, “Himalayan blackberry growing along banks encourages erosion during seasonal high flows. The shallow root system does not protect the banks well from being undercut. Once undercut, the banks collapse under the weight of the brambles; widening the channel. Steep banks, high erosion rates, and dense shade from the blackberry thickets make it more difficult for native vegetation to re-colonize the exposed banks.” The Oregon Department of Agriculture summarizes the problems with Himalayan blackberry succinctly and directly: “Himalayan blackberry is the most widespread and economically disruptive of all the noxious weeds in western Oregon. It aggressively displaces native plant species, dominates most riparian habitats, and has a significant economic impact on right-of-way maintenance, agriculture, park maintenance and forest production. It is a significant cost in riparian restoration projects and physically inhibits access to recreational activities.” I also agree whole-heartedly with their comment about controlling blackberry: “Any control strategy can be considered short-lived unless projects are planned and funded for the long-term.” Unlike Oregon, Himalayan blackberry is not officially classified as a noxious weed in Washington. However, it is classified as a Weed of Concern in King County and as Invasive Vegetation by King County DDES and several municipalities in the county. If you would like information about the status of blackberry in King County or at the state level, contact the King County Noxious Weed Program at 206-296-0290 or noxious.weeds@kingcounty.gov, or the Washington State Noxious Weed Board at 360-902-2082 or noxiousweeds@agr.wa.gov. For more information, check out our newly created web page on Himalayan and evergreen blackberry with links for further reading. Autumn rains bring weeds back to life. It’s time to check for re-growth in areas where you controlled weeds earlier in the season. Tansy ragwort, spotted knapweed, common hawkweed, and others have a way of growing back from cut stems and even flowering again late in the season. Other weeds are busy growing rosettes and this is a great time to tackle those plants: garlic mustard, milk thistle, tansy ragwort, and poison-hemlock to name a few. Wet soil makes pulling weeds easier. Now is the time to get out and pull, dig, and wrench up your weeds. The soil is moist and the weather is cool – and we can all use a little fresh air and exercise this time of year. Also, the disturbance caused by pulling weeds will do less damage to nearby roots as garden ornamentals and native plants go dormant. Weed wrenches are available for loan by contacting our program at 206-296-0290 or noxious.weeds@kingcounty.gov. Remove weedy vines from trees. It’s getting a lot easier to see English ivy and old man’s beard (wild clematis) now that deciduous trees are losing their leaves. Traces the vines to the ground and pull up the roots or at least separate the roots from the upper growth. Clear trunks of all strands of ivy and clematis up to chest height and then let the upper stems die back. Remove as much of the root as possible, especially near the base of the trees, to stop the vines from growing back up the trunks. Take care not to spread seeds. Pulling or mowing weeds in seed can make the problem even worse for future years. Pay special attention to cleaning equipment and boots when moving around your property. Remember that soil has seeds in it from the weeds growing there and that means your muddy boots are moving weeds around. When pulling weeds in seed, try to gather them up carefully in a bucket or other container to transport them to the yard waste bins or burn pile. If you have noxious weeds in seed (like tansy ragwort), bag them carefully while you pull them and then tie up the bag before taking it away. Mulch areas cleared of bindweed, blackberry and other weeds. All that hard work of repeated cutting and pulling during the growing season can be helped by covering the areas cleared with thick mulch or a combination of cardboard and mulch. In areas that get flooded in the winter, wait until spring to do this. Remove bracken fern from pastures. Although native to forests in the northwest, bracken fern is toxic to most livestock, especially in large quantities. If your pastures are filled with bracken, now is a good time to pull up as much as you can. Fertilizing fields and adding lime can help reduce the problem over time (and it’s good for your grass too). Plant natives into natural areas. Competition from well-established plants is a great way to reduce weed problems. Healthy native trees and shrubs can help hold back invasive blackberries, knotweed, Scotch broom and other aggressive invasive weeds from taking hold. This is a great time to plant shrubs, trees and perennials. Their roots will get lots of rain over the fall and winter, making them stronger and more able to survive our summer dry period next year. On September 19, the King County Council approved the noxious weed program’s report and recommendations on how county land managers might better control weeds on county lands. At the Council’s request, the noxious weed program developed a report listing county lands, identifying the responsible land manager, evaluating the land manager’s weed control efforts, and providing recommendations for how county land managers might improve the results of weed control on county lands. One of the benefits of this report is that county land managers can better identify the gaps in their knowledge about weeds on their lands. King County manages about 4,000 parcels covering 32,100 acres, or about 2 percent of the land area in the county. This vast area is composed of a wide range of properties – from large natural areas and parks to stormwater ponds and road rights-of-way. Out of that large area, a small percentage have been surveyed for weeds. Although we have a fairly good record of the regulated noxious weeds, it became clear from this report that we know very little about the extent and distribution of non-regulated noxious weeds such as Scotch broom, knotweed and English ivy. Similarly, the report shows a relatively high level of control for regulated noxious weeds by most county land managers (in fact, county land managers have a slightly higher level of control on average than private property owners) but reveals that relatively little is being done about non-regulated noxious weeds on most county lands. Although some agencies are working to control non-regulated noxious weeds, the work is generally project-based and not systematic or long-term. The report also demonstrates that the level of funding being applied to noxious weed control varies widely across agencies and doesn’t necessarily reflect the level of weeds present. For example, the report states that “The Parks and Recreation Division noxious weed control budget is extremely small in relation to the area of land managed and the extent of noxious weeds infesting this land”. The report identifies seven key strategic issues and makes recommendations for each. For example, budget consistency is a key issue identified. The recommendation is for county land managers to consistently and explicitly budget for noxious weed control. The report recommends a systematic survey of weeds on natural lands managed by the county to better define their extent and impacts. The noxious weed program is in the process of planning this survey, contingent on funding for 2008. Other recommendations follow from this survey. Using the survey results, county land managers will be able to more accurately allocate their budget and resource needs for noxious weed control on their lands. Also, multiple-year planning will be possible once the overall scope and distribution of the problem is known. Finally, the report identifies the basic need for better communication and outreach activities with park users and citizens. Increased citizen participation in volunteer and stewardship activities is identified as a key ingredient for successful long-term weed management on public lands. For more information on the county lands noxious weed report, contact Steve Burke, 206-205-6927, steven-j.burke@kingcounty.gov, or Roy Brunskill, 206-296-0290, roy.brunskill@kingcounty.gov. The Washington State Noxious Weed Control Board has hired Alison Halpern for the position of Executive Secretary. Cindy Orr, Executive Assistant to the Board, sums it up well in her announcement: “Alison has done excellent work while serving the Board as Education Specialist since 2005. Her outreach efforts, innovative education techniques, technical reports, website development, publications and customer service have made great strides in WA regarding weed awareness and control. Although Alison will be moving just across the hall, please welcome her into the new position.“ The Education Specialist position that Alison held will be discussed at the next Board meeting (see below for information on date and location). We wish Alison well in her new position! It’s time once again for the annual review of the Washington State Noxious Weed List. Every year, the Noxious Weed Committee makes its recommendations for changes to the weed list to the State Weed Board. The Weed Board then holds a public hearing to take comments and votes on the proposed changes. This is the opportunity for stakeholders and the general public to participate in setting noxious weed priorities for the state. New weeds can be added, old weeds can be removed or changed in priority, and new areas can be designated for control for specific weeds. Some of the changes being proposed at this year’s hearing that affect King County include:
The State Weed Board Meeting and Public Hearing will be held on November 14, 2007 at the Washington Cattlemen's Association, 1301 N. Dolarway Rd., Ellensburg, WA 98926. For more information, contact Alison Halpern, 360-902-2082 or noxiousweeds@agr.wa.gov. The Washington State Department of Ecology is accepting comments on the new Aquatic Noxious Weed Permit. The comment period runs Wednesday, November 14 at 5 p.m. Comments can be submitted to Ecology by mail or electronically. There are two public workshops with hearings scheduled during the comment period.
For more information, contact Kelly McLain at the WA State Department of Ecology, 360-407-6938, kelm461@ecy.wa.gov. When faced with river banks of knotweed, most people don’t know where to start. Not Dave Olson of Cedar Village. After seeing knotweed march down his beautiful stretch of the South Fork Snoqualmie River, Dave took action. Last year, he arranged for us to hold a training for his neighbors about knotweed and started rallying them to action. He took the initiative to purchase a knotweed stem injection gun and after some hands-on training with the injector, he got busy controlling the knotweed patch on his river bank and a few other areas he could get to before the rains brought the river up. At the same time, Dave advocated with us to search for funding for a more systematic knotweed project on the South Fork similar to what we began on the Middle Fork Snoqualmie last year. This year, Dave’s work really started to pay off. First, with Dave’s help, we were able to begin surveying the upper South Fork Snoqualmie to find the beginning of the knotweed and then apply some of our knotweed grant resources to controlling these uppermost infestations. We were able to control knotweed covering about 6.5 acres in Ollalie State Park and we hope to continue with the work next season if funds allow. Meanwhile, Dave once again rallied his neighbors in Cedar Village and across the river in the River Bend community and they got serious about stem-injecting knotweed along their own river fronts. Their work went a lot faster after borrowing a second stem-injector from Kelly Heintz of WA DNR. At the end of the season, Dave and 16 neighbors had stem-injected most of the knotweed along both sides of the river, about ½ mile on either side and one big island in the middle. One lesson Dave shared with us is that stem-injection doesn’t work on knotweed that has been cut back repeatedly. This is a good reminder for all of us – if you think there is a chance for using stem-injection, then don’t cut down your knotweed! The stem-injection method works best on full grown canes that are wide enough to inject. Given all the challenges and the difficulty of doing knotweed control, it is truly inspiring to see what this group of neighbors has done with limited resources and their own hard work. If you would like to find out more about Dave Olson’s project or our own South Fork Snoqualmie knotweed control work, contact Monica Walker at 206-296-0290 or monica.walker@kingcounty.gov or Sasha Shaw at 206-263-6468 or sasha.shaw@kingcounty.gov. If there ever was a good example of science proving the obvious, this is it. A recent research study from Germany has shown that weeds are spread along roadsides by vehicles. Of course this is pretty intuitive, but it is important to have good research to support our best guesses and to show us more about how this mechanism works. The researchers collected seeds dropped in tunnels to see what really falls off of vehicles on the highways. By using tunnels, they ensured they were just looking at seeds from transportation, not wind. They found out that vehicle transport doubles the seeds being dispersed near busy roads. Furthermore, this effect favored invasive species more than local native species and enabled plants to greatly expand their range. Many of the species were carried quite a long distance before dropping. In addition to fairly common weeds, they discovered seeds from invasive species that hadn’t established in the area yet but could do considerable damage if they did. All told, they found seeds from 39 different invasive species. There is a short summary of the study in New Scientist, 8/4/2007, Vol 194 Issue 2615, p,52, “Plant invaders hitch a ride”. The original article “Long Distance Dispersal of Plants by Vehicles as a Driver of Plant Invasions” by Mortiz Von Der Lippe and Ingo Kowarik was published in Conservation Biology, Vol 21, No. 4, pp. 986-996. Do you take horses or other animals into wilderness areas? If so, you have probably heard about the new requirement to use only certified weed-free straw and feed in Forest Service wilderness areas. The rule went into effect on January 1 for Pacific Northwest forests and will be in effect nationwide on January 1, 2009. The Backcountry Horsemen I've spoken to already use feed pellets, which are allowable under this ruling, so they shouldn’t have to make any changes. Commercially processed feed pellets and steamed, rolled grains are considered weed-free feed. Viable seeds are destroyed in the making of these products, so they aren’t considered a vector for spreading weeds. However, for those who bring in straw and hay, they may have to make some changes. For information on what is allowed and what isn’t, check out the WA State Weed Board’s FAQ page on weed-free forage or the USDA Forest Service’s FAQ. As we all know, prevention is the best way to stop weed invasions and to reduce the damage invasive species can cause in natural ecosystems. This is even more important in remote wilderness areas where detection of new infestations is very difficult. Using weed-free materials will be a great help in reducing introductions of weed seeds to these remote and important wild lands. For those new to the idea, here’s how the Forest Service defines weed-free: “Weed-free certified hay or crop products have been inspected according to standards used by the North American Weed Management Association (NAWMA) and member states. Under NAWMA standards, fields are inspected to ensure the absence of seed and reproductive parts from listed invasive weed species. Fields which pass the inspection are state certified and the producer may then officially label the products as a weed-free hay or crop product. In a like sense, state certified weed-free mulch comes from fields that pass inspection and are then state certified and labeled for use in restoration and re-vegetation projects.” For Washington residents, obtaining weed-free forage is still a bit of a challenge. There is no state-wide weed-free certification program in Washington, although county noxious weed boards will have the opportunity to receive training for certifying hay and crop products starting in 2008. Currently Pend Oreille County has the ability to certify weed-free hay and several neighboring states also have the ability – Oregon, Idaho, Montana and others. If you are a producer in King County and would like to find out about weed-free certification or if you have any other questions about this, please contact Steve Burke at 206-205-6927, steven-j.burke@kingcounty.gov or Alison Halpern at the State Weed Board at 360-902-2082, noxiousweeds@agr.wa.gov. The 57th Annual Weed Conference will be held November 7-9 in Yakima. This is Washington’s main weed conference for crops, ornamentals and vegetation management. The conference website is www.weedconference.org. This is a good conference for people in the field of weed control or vegetation management. Here are a few topics that seemed particularly relevant to weed control in King County:
There is still time to apply for several King County DNRP grants that are available for community-based environmental projects led by cities, tribes, schools and community-based organizations. Deadlines for these grants range from October 31 to November 5, 2007 – see below for descriptions. For applications and information visit http://dnr.metrokc.gov/wlr/pi/grants.htm or contact Ken Pritchard, (206) 296 8265, ken.pritchard@kingcounty.gov.
The domain name for all of King County websites and email addresses is changing from metrokc.gov to kingcounty.gov. This will take place in stages over the next year and a half so the old addresses will still work for awhile. However, you can start using the new emails now and we have a new easy link to our website: www.kingcounty.gov/weeds. As the transfer moves forward, the links in this newsletter and earlier additions may not work, but the quick address above will continue to work and you can always navigate to the individual pages from the index page. Hopefully this will not cause too much of an inconvenience. Please feel free to contact Sasha Shaw (206-263-6468) if you encounter any problems with accessing our website. August 2007 Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact a staff member at the King County Noxious Weed Control Program, please call 206-296-0290 or by reach them by email. |
| Please direct questions & comments regarding noxious weeds to Program Staff, King County Noxious Weed Control Program.
For questions about the
Updated: October 19, 2007 |
Related Information:
|
||
|
King County | Natural Resources and Parks | Water and Land Resources | News | Services | Comments | Search Links to external sites do not constitute endorsements by King County. |
