June 2005

TOPICS BELOW

• Weed of the Month: Tansy Ragwort
• Oh No! Garlic Mustard in Bellevue!
• Noxious Weed Found at Composting Facility
• Title II Funds for Skykomish Knotweed Project
• Grant Received for Goatsrue Control Project
• Upcoming Workshops on Noxious Weeds

Weed of the Month: Tansy Ragwort
(Senecio jacobaea)

If I had to choose one plant to be the poster child of our noxious weed program, it would be tansy ragwort. In the 1970’s, King County didn’t have a funded noxious weed program. However, a dedicated volunteer weed board and concerned citizens were already hard at work tracking tansy ragwort infestations on old-fashioned notecards and asking road crews and pasture owners to control this toxic plant. Since those early years, we have become much more high-tech with computer databases and GIS mapping, and we have a paid staff of weed specialists to roam the county hunting down noxious weeds like tansy ragwort. Unfortunately, this wily, persistent and deadly member of the dandelion family is already too well-established to stop easily and remains a widespread problem in our county. We are making progress every year, but tansy ragwort continues to torment pasture owners and vegetation management crews, and sadly, to poison horses, cattle and other animals. This is definitely a problem that will take a county-wide effort to solve.

Tansy ragwort came here by accident in the early 1900’s from Europe and Asia – as a contaminant in crop or alfalfa seed and in ballast water from ships. It quickly spread and established itself in the cool, moist climate of the Pacific Northwest, from British Columbia to northern California. It can survive east of the Cascades, but we definitely have the lion’s share on this side of the mountains. This plant is tricky to control because each plant can produce up to 200,000 seeds and these seeds can survive for up to 16 years. Most of the seeds fall within 33 feet of the parent plant, but some seeds can travel far and wide on mowers, animals, wind and water. Plants that are mowed will sprout from the crown and grow more, shorter flowering stems. Wherever there are plants, seeds lurk, ready to replace any pulled plants. Control of established infestations will take many years; there’s just no way around that.

As summer approaches, tansy ragwort flowers are starting to open up and will start setting seed in warmer parts of the county in late July and continue to seed in cooler parts of the county through September. Between now and September, our program will inspect about 2500 properties and over 1000 roadside sites for tansy ragwort. Since 2001, when we began tracking this weed county-wide, the number of new infestations has dropped off somewhat, but we are still finding new areas every year as word gets out and as our staff is able to cover more ground. Last year we recorded tansy ragwort infesting almost 100 acres of land in the county. As one population, that might not be too overwhelming. But divided into 3000 infestations, this is an immense amount of work that will take many years to achieve. We can use everyone’s help in finding infestations and especially in getting the word out on the importance of thorough and persistent control of this noxious weed.

If you have any concerns about tansy ragwort or find any new infestations, please contact us at noxious.weeds@kingcounty.gov or use our online form.

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Oh No! Garlic Mustard in Bellevue!

It was bound to happen, but it doesn’t make it any less scary. Garlic mustard, a Class A noxious weed of the highest priority, has spread out of Seattle! Other than one site in Lake Forest Park, these two new sites in Bellevue are the first infestations we know of in the county outside of Seattle. The sites are both in south Bellevue – one near Westwood Highlands Park and one near Lakemont Blvd and 164 th Ave SE. We found the garlic mustard infestations thanks to the alertness of Bellevue Parks personnel (who have done an excellent job controlling the plants on parks property) and to a private citizen who contacted us as soon as he found the plants. The garlic mustard at both of these new sites has been controlled but we are concerned that there are more infestations in Bellevue and neighboring areas. We don’t know how the weeds got to these sites so it is hard to predict where it will show up next. We will do surveys in likely areas to see if we can find more, but garlic mustard is already in seed so it will be a race to find plants before the seeds mature.

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Noxious Weed Found at Composting Facility

An unusually large infestation of absinth wormwood was recently found at a commercial composting facility, evidently transported in on a truck delivering yard waste to the facility. This Class C noxious weed is fairly common in eastern Washington, but so far we have only found scattered infestations in this county, mostly on roadsides and railroads. Because of the limited distribution here and the potential impact on pastures, the King County Weed Board requires control of this plant to stop it from spreading in our county. This discovery is a reminder that high-priority noxious weeds should not be put into yard waste because the risk of spread is too high. One city, Issaquah, has included “noxious weeds” on the list of materials to keep out of yard waste. If other cities follow suit, this should improve our chances of stopping these new invaders from spreading through yard waste transport equipment.

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Program Awarded Title II Funds for Skykomish Knotweed Project

We are excited to start work this year fighting knotweed on the South Fork Skykomish River thanks to an award of $11,250 in Title II Funds from the Mt. Baker Snoqualmie National Forest. In initial surveys we did late in 2002 with the Forest Service, we identified 21 acres of invasive knotweed in 38 infestations on the South Fork of the Skykomish River, Money Creek and Beckler River. Weed specialist Monica Walker will be leading the project by following up on those surveys and beginning to control priority infestations in the upper watershed. She will coordinate efforts with the stakeholders in the watershed and employ WCC crews to carry out the control work. We are hoping that this is just the beginning of what we will be able to accomplish in stopping the spread of invasive knotweeds in this high quality watershed.

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Pulling Together Grant Received for Goatsrue Control Project

Thanks to a Pulling Together grant our program has received from the National Fish and Wildlife Foundation, we will be able to aggressively control all known infestations of goatsrue, a Class A noxious weed, in King County and track down any new sites through a public outreach campaign and surveys of the areas near known populations. Weed specialist Amy Yahnke will be spearheading our efforts to eradicate this high priority weed, considered a high priority noxious weed by both Washington State and the Federal Government. We recently saw this plant described (but not for sale) on a gardening website (http://davesgarden.com/guides/pf/go/1200/index.html) so it is possible that we will find intentional plantings as well as escaped populations. However, if we act quickly and get the word out, hopefully we can stop this plant from being planted here and get closer to our goal of eliminating it from Washington altogether.

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Upcoming Workshops on Noxious Weeds

The noxious weed program is holding free public workshops on invasive plants and noxious weed management. The goals and topics for these vary and there may be space limits so please contact our program for more information if you are interested.

• June 14, 6:30pm-8:30pm, Olympic View Elementary, 504 NE 95th St., Seattle, "Neighborhood Bullies: Invasive Weeds in Urban Lands." A slide show on invasive plants that are threatening community parks, waterways and natural areas. Learn how invasive weeds spread, where they come from, and what communities can do to stop them from spreading any further. Register by calling Sasha Shaw at 206-263-6468 or by email at sasha.shaw@kingcounty.gov.
  
• June 27, 6:30pm-8:00pm, Maple Valley Library, 21844 SE 248th St., Maple Valley, "Pasture Bullies: Noxious Weed Workshop for Rural Landowners". Free workshop on pasture weeds and invasive plants that are wreaking havoc in the county. Come learn about common and uncommon weeds with a slide show and a live weed show and tell. Everyone is welcome but space is limited so please register ahead with Sasha Shaw at 206-263-6468 or sasha.shaw@kingcounty.gov.

We also hold workshops and presentations for specific groups. Please contact Sasha Shaw or 206-263-6468) if you would like a presentation on invasive plants or noxious weeds for your group, staff or community.

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.

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