InvasiveInvasive KnotweedKnotweed ControlControl inin KingKing County,County, WashingtonWashington

Sasha Shaw Education Coordinator King County Noxious Weed Program Seattle, 206-263-6468 www.dnr.metrokc.gov/weeds WhereWhere isis KingKing CountyCounty Anyways?Anyways? ¾ LocatedLocated inin WesternWestern WashingtonWashington ¾ CoversCovers 2,1002,100 squaresquare milesmiles extendingextending fromfrom thethe crestcrest ofof thethe CascadeCascade RangeRange toto PugetPuget Sound,Sound, includingincluding VashonVashon IslandIsland ¾ 1.81.8 millionmillion people,people, includingincluding SeattleSeattle ¾ AboutAbout 1,5001,500 farms,farms, mostmost underunder 5050 acresacres ¾ 25,00025,000 acresacres ofof parksparks andand trailstrails ¾ 38%38% ofof thethe countycounty isis ownedowned byby StateState andand FederalFederal GovernmentGovernment ¾ MajorMajor riversrivers include:include: White,White, Green,Green, Cedar,Cedar, SnoqualmieSnoqualmie (South,(South, Middle,Middle, North),North), SouthSouth ForkFork Skykomish,Skykomish, SammamishSammamish KnotweedKnotweed inin KingKing CountyCounty ¾ Widespread, urban to rural and coastal to foothills; heaviest concentrations found along riparian corridors and road rights-of-way, also in residential gardens, wetlands, and upland areas ¾ UW Herbarium: most collections made since 2001, a couple of earlier collections in 1973 and 1987 ¾ Four invasive knotweed species occur, at times together • P. X bohemicum is most common, usually male, sometimes female flowers, 2-3 meters tall • P. cuspidatum all female, 1.5 to 2.5 meters tall, fairly widespread • P. sachalinense, both female and male specimens (usually female), 5 meters tall, not as common but can be quite dominant in some areas • P. polystachyum, bisexual, a few scattered populations, each very dense but not expanding into adjacent areas noticeably quickly ¾ One long-time King County resident first saw knotweed in the 1960’s in North Bend 20012001 SurveySurvey ofof RuralRural KingKing CountyCounty ¾ Roads, trails, & levees of east and north King County z Snoqualmie Watershed: • Heavy infestations along lower river and also upland and roadside, less so on tributaries and in upper watershed z Cedar River Watershed: • Main river and creeks had sizable infestations, more limited within the Cedar River Watershed z Green River Watershed • sizable infestations on lower, less on middle and upper watershed z : • Significant infestations but limited or none on tributaries and upper z Greenwater River (on border with Pierce County) • None seen z Himalayan Knotweed: only a few limited populations found ¾ Conclusions: z Identified riparian areas that had limited knotweed where control might be cost-effective and provide significant habitat improvements

PublicPublic InterestInterest andand ConcernConcern aboutabout KnotweedKnotweed inin KingKing CountyCounty

¾ MoreMore peoplepeople atat workshopsworkshops andand eventsevents areare awareaware ofof knotweedknotweed nownow thanthan 33 yearsyears agoago ¾ GrowingGrowing interestinterest inin gettinggetting knotweedknotweed controlledcontrolled onon publicpublic propertyproperty

z In other words, we get a lot more complaints than we used to about knotweed! ¾ MostMost peoplepeople whowho havehave itit wantwant toto getget ridrid ofof itit

z Most who have tried have not been very successful

z Increasing demand for better control information and for help doing the control ReasonsReasons LandownersLandowners GiveGive forfor NotNot ControllingControlling KnotweedKnotweed ¾ Past efforts were mostly not effective ¾ Physical control is too difficult

z Either have to dig too deep or have to cut stems more often than they can manage ¾ Chemical control is too expensive, too complicated, or simply not acceptable to them for other reasons

z Don’t know where, when, or what to spray

z Stem-injection guns and aquatic herbicides are expensive

z Permit and licensing requirements are expensive and/or confusing

z Lack of spraying experience / scared of the unknown

z Don’t want to use herbicides (at all) ¾ Worry that knotweed will just re-infest their property from upstream or roadsides after all their hard work (what’s the point if everyone doesn’t control it!) MeasuringMeasuring thethe PublicPublic InterestInterest

¾ We responded to 100 phone or email inquiries or requests for presentations on knotweed in 2006

z This was 13% of our total inquiries for the year; an increase of 100% from three years ago

z 5 presentations or training workshops solely on knotweed; and most others included knotweed as a featured weed ¾ Knotweed fact sheets distributed in 2006

z Printed copies: 1,010 distributed at events and by mail

z Online version: 989 downloads of the online version ¾ Conclusion

z Growing concern and more efforts to control but still not as much as there could be given the wide distribution Knotweed,Knotweed, Knotweed,Knotweed, EverywhereEverywhere KingKing CountyCounty KnotweedKnotweed ProjectsProjects

¾ ShareShare similarsimilar strategiesstrategies z Cooperative and inclusive of all stakeholders • Need strong community and stakeholder support z Comprehensive and top-down z Protect and restore fish and wildlife habitat ¾ PresentPresent differentdifferent challengeschallenges z Public vs. private ownership z Restrictions on methods – EA’s/BA’s, owner choices z Funding limitations (this is pretty universal!) ¾ NoxiousNoxious WeedWeed ProgramProgram projectsprojects areare onlyonly partpart ofof thethe knotweedknotweed effortsefforts inin thethe countycounty z Cities like Lake Forest Park, Kent, Maple Valley, etc z Private landowners Miller/Walker Creeks KnotweedKnotweed ProjectsProjects OverviewOverview

¾ GreenGreen RiverRiver KnotweedKnotweed CWMACWMA

z Upper and Middle Green River, lower Soos Creek and Crisp Creek ¾ SouthSouth ForkFork SkykomishSkykomish KnotweedKnotweed CWMACWMA

z , Tye River, upper South Fork Skykomish, ¾ MiddleMiddle ForkFork SnoqualmieSnoqualmie

z 2006 was first season of work

z Middle Fork Snoqualmie, Roaring Creek ¾ Miller/WalkerMiller/Walker CreekCreek ProjectProject

z Knotweed is one of many invasive weeds in this project, started in 2006 20062006 GrantsGrants andand PartnerPartner ContributionsContributions Source Amount Match Rivers

USDA-FS $31,200 $31,200 Green, Mid Fork FHP Snoqualmie WSDA $15,000 Mid Fork (+ herb.) Snoqualmie USFWS $6,678 $7,000 Green Title II/RAC $7,226 $7,300 SF Sky

CWMA $10,884 All three Partners TOTALS $70,988 $45,500 $116,488 DataData CollectionCollection MethodsMethods

¾ SurveysSurveys z Roadside and trailside spot checks z Stream-walking z River surveys by inflatable rafts and kayaks ¾ DataData –– collectedcollected withwith GPSGPS unitsunits z Knotweed species, area infested, % cover of knotweed, growth stage, habitat type, proximity to river, condition of knotweed, UTM coordinates z Treatment method recommendation based on site conditions z Gross area=total area of knotweed infested land z Cumulative area=sum of the area of knotweed patches DataData Collection:Collection: ReallyReally HardHard WorkWork ControlControl MethodsMethods UsedUsed

¾ Foliar spray z From early July to mid-October z Backpacks or truck-mounted tank with hose z 2 % Aquamaster or AquaNeat (glyphosate) plus 1% Habitat (imazapyr) and 1% Agridex (surfactant) ¾ Stem-injection z From mid-July to late September z JK Injection stem-injectors, mostly long needles but short needles later in season z 3 ml undiluted Aquamaster or AquaNeat (glyphosate) in every cane with at least ½ inch wide stems (between first two nodes) ¾ Cut and Spray Combination z Did this in 2004 and 2005 but not 2006 because results showed no increase in control over spraying alone ¾ Covering with Geotextile Fabric z One site had this treatment; flooded areas lost fabric and knotweed continued to come up around fabric CoveringCovering MethodMethod

Uh Oh!! FoliarFoliar TreatmentTreatment StemStem--InjectionInjection

Dead knotweed canes following treatment with stem injection gun GreenGreen RiverRiver KnotweedKnotweed ProjectProject

¾¾ MostlyMostly publicpublic landslands –– predominantlypredominantly state,state, countycounty andand citycity ¾¾ SomeSome privateprivate propertiesproperties ¾¾ FishFish hatcheryhatchery ¾¾ MostMost sitessites treatedtreated werewere withinwithin 600600 feetfeet ofof thethe river,river, mostmost rightright onon thethe riverriver ¾¾ OneOne large,large, highlyhighly visiblevisible sitesite (Neely(Neely Mansion)Mansion) aa bitbit fartherfarther offoff waswas alsoalso treatedtreated

20062006 GreenGreen RiverRiver SurveysSurveys

¾¾ IntensiveIntensive riverriver surveysurvey ofof 16.516.5 riverriver milesmiles ¾¾ RemainingRemaining 3838 riverriver milesmiles spotspot checkedchecked atat knownknown sites,sites, roadroad crossings,crossings, andand selectselect propertiesproperties ¾¾ 2.52.5 milesmiles ofof SoosSoos andand CrispCrisp CreekCreek surveyedsurveyed onon footfoot wherewhere theythey flowflow intointo thethe GreenGreen RiverRiver 20062006 ControlControl

¾ AllAll knotweedknotweed onon thethe upperupper 5454 milesmiles fromfrom thethe upperupper watershedwatershed toto AuburnAuburn NarrowsNarrows controlledcontrolled

z 27 sites on the river or < 500 ft from the river were controlled

z An additional 22 sites located > 500 ft from the water were not controlled due to budget constraints ¾ AlsoAlso 1313 sitessites onon firstfirst couplecouple ofof milesmiles ofof SoosSoos andand CrispCrisp CreekCreek werewere treatedtreated

z Additional sites have been reported on Soos Creek but a detailed survey still needs to be done ResultsResults

¾ Stem-injection still being used along river’s edge and where selectivity is especially important

z Getting about 90-99% effectiveness ¾ Foliar spray with glyphosate or glyphosate/imazapyr for re-growth, large sites

z Necessary follow-up to stem injection due to smaller stems on re-growth

z Results are mixed – 75% to 90% ¾ Net infested acres reduced in project area

z From 9.6 acres in 2005 to 6.7 acres in 2006, a 30% reduction ¾ Density of knotweed has decreased from >75% cover to <25% on all sites treated (most <10%) ¾ Two sites had no knotweed in 2006; one new site identified LargeLarge SitesSites areare ReallyReally Persistent!Persistent!

Neely Mansion Site: 3 years of treatment

Before control, starting to cut

2006, after spraying, still some regrowth

2005, showing re-growth ¾ Above: Flaming Geyser State Park regrowth early 2005 ¾ Left: Same area prior to treatment 2004 FutureFuture IssuesIssues onon thethe GreenGreen RiverRiver

¾ HeadingHeading intointo maintenancemaintenance phasephase forfor upperupper andand middlemiddle watershedwatershed z TPU is controlling their own sites now z Some other landowners/managers may also be able to take on follow up monitoring and control z Ongoing need for our program to re-survey and respond to new growth ¾ But,But, Wait,Wait, ThereThere’’ss MoreMore z 2006 floods may mean a resurgence of new sites z Still considerable knotweed populations in upland areas of the watershed and on upper parts of some creeks flowing into the river z Lower Green River and its watershed remain heavily infested with knotweed Snoqualmie/SkykomishSnoqualmie/Skykomish ProjectsProjects MiddleMiddle ForkFork SnoqualmieSnoqualmie ProjectProject WhyWhy thethe MiddleMiddle ForkFork Snoqualmie?Snoqualmie?

¾ Complemented and expanded on existing efforts to remove invasives in watershed z MidFORC Community Group z Mountains to Sound Greenway Trust z Cascade Land Conservancy z King County Parks ¾ Middle Fork basin drains 8% of King County (over 110,000 acres) and is the longest river system in the county ¾ Snoqualmie Valley is one of the highest quality areas in the county for agriculture, forestry and natural resources ¾ Middle Fork is mostly free-flowing without fill and bank protection and provides high-quality habitat to cutthroat, rainbow trout and whitefish ¾ High quality salmon runs below Snoqualmie Falls depend on upper river’s water quality MiddleMiddle ForkFork SnoqualmieSnoqualmie ProjectProject ¾¾ InitialInitial surveys,surveys, grantgrant request,request, intensiveintensive surveys,surveys, andand controlcontrol allall completedcompleted fromfrom AprilApril toto SeptemberSeptember 20062006

z $39,231$39,231 spentspent inin 20062006 (not(not countingcounting ourour match)match) ¾¾ RaftingRafting surveysurvey showedshowed upperupper limitlimit ofof knotweedknotweed asas RMRM 4.54.5 ¾¾ RoadsideRoadside surveysurvey identifiedidentified aa fewfew roadsideroadside sitessites inin upperupper watershedwatershed ¾¾ AllAll qualifiedqualified asas prioritypriority sitessites MiddleMiddle ForkFork SnoqualmieSnoqualmie SummarySummary ¾ 55 ½½ riverriver milesmiles werewere controlledcontrolled (including(including 11 milemile onon aa tributarytributary RoaringRoaring Creek)Creek) ¾ 5353 totaltotal sitessites werewere foundfound onon riverriver andand 5151 werewere controlled,controlled, mostmost onon privateprivate propertyproperty z 44 sites privately owned, 4 King County, 5 Washington State ¾ AllAll sitessites treatedtreated byby stemstem--injectioninjection withwith glyphosate,glyphosate, mostmost donedone withwith workwork crewscrews fromfrom WCCWCC andand EarthcorpsEarthcorps z 18.5 days with crews of 6 including crew supervisor ¾ 10.810.8 netnet acresacres treatedtreated withinwithin 27.527.5 grossgross infestedinfested acresacres z 0.75 acres not treated due to running out of time and money Mid Fork Snoqualmie 2006: Before and After Shots SkykomishSkykomish RiverRiver CWMACWMA

¾ River provides high value habitat for fish and wildlife as well as for recreation and other uses ¾ Knotweed infestations are widespread downriver of Skykomish but upper reaches are not as bad ¾ Goal of project is to halt the invasion of knotweed in the upper watershed and to begin to reduce the impact on the river as a whole ¾ Received $10,000 in Title II funds in 2005 and $7,200 in 2006 (matched equal amounts in both years) ¾ Project area includes upper reaches of South Fork Skykomish, Foss and Tye Rivers ¾ Crosses private, forest service, state and BNSF property Controlled 2006 SkykomishSkykomish RiverRiver CWMACWMA

¾ Surveyed 21 non-contiguous miles in 2005 and 15 miles in 2006 including a raft survey, stream-walking on smaller tributaries and road surveys ¾ Project Area: 21.2 gross acres – 9.3 net acres treated 2005, 2.42 net acres treated 2006 (less $$ available) ¾ Crew time: 6 days of 6 member crews, down from 13 days in 2005 due to decreased funding ¾ Methods used: stem-injection near river, foliar spray on re-growth and road rights-of-way

z Contracted with WCC and Earthcorps crews

z USFS hired contractor to spray ROW sites using glyphosate

z 2 private landowners adjacent to river began controlling knotweed on their own Knotweed

Knotweed infesting a remote area on the upper Skykomish River Same site after treatment in 2005 Very little knotweed left in 2006, willows and other native species remain MillerMiller andand WalkerWalker CreekCreek ProjectProject

¾ Watershed-wide invasive weed control ¾ Port of Seattle funded ($35,000 grant) ¾ Knotweed and other weeds ¾ Relatively high quality urban stream through Burien and Normandy Park 4,100 sq ft of knotweed controlled over 39 ¾ Strong community support sites, most small and patchy and less than 25% cover, a few denser sites FutureFuture KnotweedKnotweed ProjectProject PrioritiesPriorities ¾¾ ContinueContinue toto fosterfoster andand developdevelop cooperativecooperative partnershipspartnerships andand locatelocate fundingfunding sourcessources ¾¾ MonitorMonitor sitessites treatedtreated inin previousprevious yearsyears ¾¾ ProvideProvide followfollow--upup treatmenttreatment wherewhere neededneeded ¾¾ ContinueContinue rapidrapid responseresponse controlcontrol ofof newnew infestationsinfestations wherewhere possiblepossible ¾¾ ConductConduct additionaladditional surveyssurveys ¾¾ ContinueContinue offeringoffering citizencitizen educationeducation andand technicaltechnical supportsupport SashaSasha ShawShaw KingKing CountyCounty NoxiousNoxious WeedWeed ProgramProgram 201201 SouthSouth JacksonJackson St,St, SuiteSuite 600600 Seattle,Seattle, WAWA 9810498104 206206--263263--64686468 [email protected]@metrokc.gov www.dnr.metrokc.govwww.dnr.metrokc.gov/weeds/weeds