 |
 |
|
KC Weed News - May 2007 (PDF Version for Printing) TOPICS BELOW
In 1997, when I first stumbled onto the almost solid stretch of meadow knapweed growing along NE 116 th St. in Kirkland, it seemed very strange to see a rangeland weed in the middle of an urban center. Then I followed the trail of pretty pink-purple flowers down 112 th Ave NE to a hillside covered with an interesting mix of Scotch broom, spotted knapweed and meadow knapweed. It was an exposed, sandy hill that was perfect habitat for these weedy plants. The strange thing was the hill’s location behind a charming apartment complex called the Park at Forbes Creek that borders an equally lovely salmon creek. The broom and spotted knapweed were pretty much restricted to the sandy hillside, but the meadow knapweed had found its way up the road, into commercial and vacant lots, and even into fields and lawns with well-established grass and other vegetation. Later on, I also found meadow knapweed growing in some really nice pastures on the outskirts of Kirkland as well as along more roadsides and even a park or two. Clearly this was a plant that was well-suited to western Washington conditions. It is possible that both spotted and meadow knapweed traveled to Kirkland on the railroad that cuts through town. However, it is also very interesting that, according to a long-time resident of the area, the site of the Forbes Creek Apartments had formerly been a gravel quarry. My source even told me that he remembered watching the meadow knapweed spread from the former quarry up to NE 116 th St. and beyond. I don’t know when the site was a quarry, but the apartments were built in 1988. It looks like meadow knapweed has been spreading in Kirkland since at least the 1980’s if not before. Since that first year our program started tracking meadow knapweed, we have found this plant growing on 74 parcels and roadsides in Kirkland alone. And even worse, meadow knapweed is not found only in Kirkland. In 2006, we found a total of 106 sites in the county as a whole, covering an area of 8.3 acres in total. Besides the rather unexpected cluster of infestations in Kirkland, most of the other populations are in the Kent/Covington area, south King County or near railroads and highways. We continue to find new sites and some of the established populations are proving very persistent and tough to eliminate. In King County, we discovered what other west side counties have as well. This type of knapweed is altogether too well-suited to our climate for comfort. It grows very well in rich pastures as well as poor soils along roads and railroads. In fact, it seems to prefer moister soil, unlike the other knapweeds that are mostly restricted to dry, disturbed sites in western Washington. In eastern Washington, meadow knapweed is fairly small and grows in discrete patches. In western Washington, however, meadow knapweed can grow well over 3 feet tall, especially where it gets enough rain, and can form extensive monocultures, completely pushing out grasses and other pasture species. Meadow knapweed may get its competitiveness from its origins as a fertile hybrid of two other knapweeds – brown and black – neither of which are particularly common in Washington (although we have had small patches of brown knapweed in King County at times). Often with fertile hybrids, the child plant has greater vigor and a broader tolerance to a variety of conditions than either parent plant. Meadow knapweed has both of these advantages. Its vigorous, deep roots keep it alive through our summer drought and allow it to out-grow grasses and other plants when water becomes available. Its tough, unpalatable leaves resist insects and grazing. And its pretty flower heads produce numerous seeds that quickly germinate given any exposed soil. For information on identification and management of meadow knapweed, check our page on meadow knapweed or call one of our weed specialists at 206-296-0290. Other good resources online include: http://cru.cahe.wsu.edu/CEPublications/pnw0566/PNW0566.pdf and http://www.co.whatcom.wa.us/publicworks/pdf/weeds/meadow_knapweed2.pdf. Because of meadow knapweed’s impacts to pasture productivity and native habitat and its relatively limited distribution, control is required in King County. We encourage you to report sightings of this plant as soon as possible so that we can notify the appropriate agency or property owner. You can call us at 206-296-0290, send an email to noxious.weeds@kingcounty.gov or use our online infestation report form. Time is running out for stopping garlic mustard. Now is the time to make sure no flowering plants remain – pull up and bag the garlic mustard before the seed pods mature. If you need more motivation to take this plant seriously, check out the recent news article on garlic mustard on the Columbia Gorge in Oregon. The spread of this plant along our state’s southern border is definitely alarming and even inspired one homeowner along the Gorge to say: “The county should be out here knocking on every door and telling property owners to get rid of it”. Keep watching for giant hogweed in urban areas, parks, and anywhere else it has been spotted in the past. Check the noxious weed map for King County to see if it has been seen in your area. Hogweed’s large, jagged leaves and thick, purple-blotched stems are tall enough to spot above other plants now and the flowering stems are starting to develop. Hogweed won’t be full size until June but controlling it now is easier before flower heads open. CAUTION: avoid getting the sap on your skin because it can cause painful blisters and scarring. Contact our program if you find this plant in a new location in the county. Mow Canada thistle when you see green buds (probably by late May or early June). The root reserves are lowest right as buds develop so mowing at this time and repeating each time buds form can help weaken the plants. If areas are grazed heavily and thistles remain, cutting the thistle can really help reduce its vigor and give the grasses a chance to recover. If bull thistle is your problem, just cut the stems an inch or two below the surface before the flowers form (usually by June). Get out your weed wrenches for Scotch broom pulling. The soil is still fairly loose in most places and flowering broom plants are easy to spot this time of year. However, pulling broom by hand is not an easy matter once they get over three feet tall. Luckily, most broom infestations can be effectively controlled with a handy tool called a weed wrench. Many cities and non-profit organizations are using weed wrenches for broom control and might have them available for special projects. King County residents can also borrow one of our weed wrenches – just call Suzanne at 206-296-0290 to reserve one and then come to our office in Seattle to pick it up. Be an informed consumer – avoid introducing invasive plants into your garden. Take along a King County Noxious Weed List when you go shopping at plant sales and nurseries this spring and call our office for a copy of Garden Wise: Non-Invasive Plants for Your Garden. Also, ask or research how the plant you are considering behaves in the garden and beyond. Avoid plants that self-seed or spread aggressively beyond where they are planted. If your neighbor has tons of seedlings to share, find out more about the plant before accepting their gift. It’s nice to have plants that fill in an area quickly, but if the seedlings are getting out into natural areas and damaging ecosystems, it’s better to choose a less dangerous alternative. Time to get busy on bolting and early flowering weeds. This is the month when most noxious weeds really get going and many will be flowering by the end of the month. What this means is that now is the best time to find and control many noxious weeds. Before flowers form, members of the sunflower family like tansy ragwort, knapweeds and hawkweeds can still be controlled with herbicides and can also be pulled or dug up without having to collect the flowering stems for disposal. In May, expect to see the following noxious weeds flowering: Dalmatian toadflax, milk thistle, spotted knapweed, yellow hawkweed, orange hawkweed, possibly meadow knapweed and sulfur cinquefoil and of course garlic mustard and gorse, already moving toward seeding. If we are lucky, we won’t see tansy ragwort flowering in May, but it will definitely start bolting this month. Giant hogweed is also starting to form flowering stems but probably won’t have flowers this month. Report designated Class A and B noxious weeds on roads and trails . King County has started their annual roadside vegetation management program (see their recent press release for more information. Cities and State crews are also getting busy working on noxious weeds along roadsides. However, even with their hard work and our own efforts to send them locations of regulated noxious weeds, we can't be everywhere and some sites get missed. If you see a patch of tansy ragwort or any other regulated noxious weed growing on a road right-of-way or park, contact our office and we will make sure the right agency or property owner gets notified quickly. We can be reached at 206-296-0290 or you can use our online infestation report form. We’ve been busy producing lots of new fact sheets on noxious and invasive weeds. Check out the brochures page for new and updated fact sheets on these weeds: bittersweet nightshade, blackberry, bull thistle, Canada thistle, garden loosestrife, knotweed, poison hemlock, meadow knapweed, milk thistle, Scotch broom, and yellow archangel. Other fact sheets and brochures are also available and we have more in the works, so check back often! All our materials are available printed as well. Just call Suzanne at 206-296-0290 and she can mail you what you need. In addition to working individually with landowners, the King County Noxious Weed Control Program offers free workshops on invasive and noxious weeds. There are classes scheduled throughout the county from early May through early July. All classes are free and open to the public. Details are available at www.dnr.metrokc.gov/weeds/classes.htm.
I also encourage community associations to contact our program if they would like to schedule a presentation on noxious weeds in their area. For more information on any of these workshops or to schedule a presentation contact Sasha Shaw at 206-263-6468 or by email at sasha.shaw@kingcounty.gov. The noxious weed program will once again offer two workshops for vegetation management crews and others who need to identify and manage noxious weeds as part of their work. Using live specimens and slides, we will focus on how to identify and control noxious weeds that are designated for control in King County. In addition, we will have a guest speaker on the topic of strategies to reduce herbicide use through non-chemical weed control methods. We have applied for WSDA pesticide recertification credits for both of these classes. See our workshops schedule for a more detailed agenda.
To register and receive updates on the class agenda, please contact Sasha Shaw at 206-263-6468 or sasha.shaw@kingcounty.gov. Please feel free to pass this information on to others who may be interested as well. Both classes are free and open to the public. Come join us and lots of other great groups in Tukwila on May 12. This is a free, all-day event to educate and inspire people to welcome wildlife - such as birds, butterflies, and other wildlife - into their backyards, gardens and communities. The event will host a variety of activities and educational opportunities on how to attract and support wildlife through garden and landscape practices, and creating and preserving wildlife habitat in our region. Our program will have a booth with lots of noxious weed information and handouts and we are also giving a talk on noxious weeds and climate change. Saturday, May 12 - 10am to 3pm, Tukwila Community Center - 12424 42nd Ave. S., Tukwila, (206) 768-2822. http://www.backyardwildlifefair.org/ The Class B noxious weed garden loosestrife (Lysimachia vulgaris) currently covers about 40% of the Lake Sammamish shoreline, including significant stretches of the two large public parks at either end of the lake. While agencies work on getting the weed under control on public land, King County is asking for private homeowners to voluntarily control any of these plants on their lakefront property. Since each of the four cities bordering Lake Sammamish have different regulations on shoreline vegetation control, and since merely removing the weeds without replanting the shoreline could potentially result in erosion, King County will hold two public workshops in July 2007 on garden loosestrife control, city regulations, and shoreline naturescaping. All shoreline homeowners will receive an invitation to the workshops, and the general public is also welcome to attend. For more information contact Katie Messick at 206-296-0290 or Katie.messick@kingcounty.gov. King County received an Early Infestation Grant from the Washington State Department of Ecology to attempt eradication of garden loosestrife (Lysimachia vulgaris) from the mainstem Snoqualmie River. Surveys in 2005 and 2006 located small, scattered patches of the weed between Fall City and the mouth of the river in Snohomish County. Over the next five years, contractors will spot spray the garden loosestrife with the aquatic formulation of triclopyr, which has proven effective against garden loosestrife elsewhere. King County is working to inform all stakeholders and secure permission to spray the weeds from all affected landowners along the river. Please contact Katie Messick (katie.messick@kingcounty.gov) with any questions. Stop the spread of aquatic hitchhikers! King County has established a pilot program to train volunteers to survey lakes with public boat launches for Brazilian elodea and other submerged noxious weeds. The goal is early detection and rapid response to these hard-to-find and harder-to-control weeds. Based on similar programs in New England, the King County Weed Watchers will survey eleven lakes in south King County in 2007. The volunteers are being trained to identify Brazilian elodea, hydrilla, fanwort and Eurasian watermilfoil as well as native look-alikes and a variety of floating and emergent plants. If the program goes well in 2007, we will expand it to other lakes in future years. For more information, contact Katie Messick at 206-296-0290 or Katie.messick@kingcounty.gov. April 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: May 2, 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. |
