Backyard Invasions: Backyard Invasions: Noxious Weeds in Noxious Weeds in Seattle's Greenspaces Seattle's Greenspaces Sasha Shaw Sasha Shaw King County Noxious Weed Program King County Noxious Weed Program 206-296-0290 206-296-0290 [email protected][email protected]
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Backyard Invasions: Noxious Weeds in Seattle's Greenspaces Sasha Shaw King County Noxious Weed Program [email protected].
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Backyard Invasions: Noxious Backyard Invasions: Noxious Weeds in Seattle's Greenspaces Weeds in Seattle's Greenspaces
Sasha ShawSasha ShawKing County Noxious Weed ProgramKing County Noxious Weed Program
DefinitionsDefinitions Impacts of Invasives in Urban AreasImpacts of Invasives in Urban Areas Invasive Vines, Trees, Shrubs and Other Invasive Vines, Trees, Shrubs and Other
PlantsPlants What Can We Do?What Can We Do? ResourcesResources
What is a Weed?What is a Weed?
a plant out of placea plant out of place
takes water, nutrients or takes water, nutrients or habitat from desired habitat from desired plants (subjective)plants (subjective)
threatens an area’s threatens an area’s values or benefitsvalues or benefits
Are All Weeds Bad All the Time?Are All Weeds Bad All the Time?
Lots of weedy plants Lots of weedy plants are used by birds, are used by birds, insects and peopleinsects and people
One person’s weed One person’s weed can be another can be another person’s pride and joyperson’s pride and joy
Native plants used to Native plants used to be called weedsbe called weeds and still are for some!and still are for some!
American goldfinch lunches on bull thistle seeds
What are Native Plants?What are Native Plants?
Adapted to local Adapted to local climate and soils; climate and soils; foundation for local foundation for local ecosystemecosystem
Co-evolved with Co-evolved with native animalsnative animals
Provide food, Provide food, shelter, nesting shelter, nesting materials for wildlifematerials for wildlife
Gumweed (Grindelia integrifolia) on Puget Sound beach, native to Pacific coast from BC to California
What is an Invasive Weed? What is an Invasive Weed?
Non-native, Non-native, aggressively aggressively spreading spreading DestructiveDestructive Competitive Competitive Difficult to Difficult to
controlcontrol
Invasive knotweed spreading into an open forest
Good PlantGood Plant Bad WeedBad Weed
Bleeding Heart (Dicentra formosa) Herb Robert (Geranium robertianum)
Some invasive weeds resemble native plantsSome invasive weeds resemble native plants Invasive weeds exploit conditions similar to their home Invasive weeds exploit conditions similar to their home
range and don’t have natural enemies keeping them in range and don’t have natural enemies keeping them in checkcheck
What is a Noxious Weed?What is a Noxious Weed?
Non-native plant that impacts Non-native plant that impacts agriculture, wildlife, human agriculture, wildlife, human health, land values or natural health, land values or natural resourcesresources
Defined and regulated by Defined and regulated by state law (RCW 17.10)state law (RCW 17.10) control required only where weed is control required only where weed is
not widespreadnot widespread goal of law is to prevent spread of goal of law is to prevent spread of
new invaders to un-infested areasnew invaders to un-infested areas
What are the Weed Classes?What are the Weed Classes?
Class A WeedsClass A Weeds – new invaders, control – new invaders, control required statewide, still a chance to eradicaterequired statewide, still a chance to eradicate
Class B and C DesignatesClass B and C Designates – control required in – control required in King County, still have a chance to stop them King County, still have a chance to stop them from getting establishedfrom getting established
Non-Designates and Weeds of ConcernNon-Designates and Weeds of Concern – – widespread invasive weeds in King County, widespread invasive weeds in King County, control not required but definitely a good idea control not required but definitely a good idea whenever possible!whenever possible!
How do weeds get here?How do weeds get here?
Orange Hawkweed: Orange Hawkweed: from garden store to from garden store to mountain meadowmountain meadow
Noxious Weeds Noxious Weeds Run Amok:Run Amok:
Impacts of Invasive WeedsImpacts of Invasive Weeds
EnvironmentalEnvironmentalImpactsImpacts
Invasives like English Ivy transform forests and natural areas, hurting trees, native plants and native wildlife species
Purple and garden loosestrife in Portage Bay choke out native plants and destroy wildlife habitat.
Diverse wetland habitat in the Nisqually delta provides food and shelter for many different kinds of birds and animals.
Impacts to WaterwaysImpacts to Waterways
Restoration crew removes reed canary grass that had filled in a stream channel, increasing flooding and reducing fish habitat
Impacts to RecreationImpacts to Recreation
Fragrant water lily and Eurasian watermilfoil in Lake Sammamish
Impacts to Public HealthImpacts to Public Health
Giant Hogweed - Sap sensitizes skin to UV radiation, resulting in severe burns, blisters, painful dermatitis and scarring.
Impacts of Invasives in SeattleImpacts of Invasives in Seattle
City-wide Surveys 1999-2000 and 2005City-wide Surveys 1999-2000 and 2005 8,000 acres of public lands in Seattle8,000 acres of public lands in Seattle Classified habitat types throughout the cityClassified habitat types throughout the city Recorded species names and percent Recorded species names and percent
covercover Study of all forest types in SeattleStudy of all forest types in Seattle Mapped density of invasivesMapped density of invasives
Ella Elman & Nelson Salisbury, EcologistsElla Elman & Nelson Salisbury, Ecologists(206) 522-0334(206) 522-0334www.seattleurbannature.orgwww.seattleurbannature.org
Invasive Plant Species CitywideInvasive Plant Species Citywide
11%
25%
17%
18%
20%
9%
In 47% of Seattle’s forests, the majority of the plant cover consists of invasive species
Most Prevalent Invasive SpeciesMost Prevalent Invasive Species
Five most invasive species in Seattle based on 1999-2000 survey
Seattle has 2500 acres of forested parklandSeattle has 2500 acres of forested parkland 60-70% of tree regeneration in Seattle’s forests 60-70% of tree regeneration in Seattle’s forests
is non-nativeis non-native Shade tolerant species are the biggest threat: Shade tolerant species are the biggest threat:
English holly and cherry laurel are the worstEnglish holly and cherry laurel are the worst European species of mountain-ash, hawthorne, and European species of mountain-ash, hawthorne, and
cherry are found throughout Seattle’s forests cherry are found throughout Seattle’s forests
If nothing is done, 30 to 40 years from now our If nothing is done, 30 to 40 years from now our forests will look dramatically different than they forests will look dramatically different than they do todaydo today
Tree RegenerationTree Regeneration
Conifer/deciduous ForestsConifer/madrone Forests
Case Study: Case Study: Deadhorse Deadhorse
Canyon InventoryCanyon Inventory
Distribution of Distribution of English holly and English holly and cherry laurelcherry laurel Red and orange Red and orange
high densityhigh density Yellow moderateYellow moderate Green lowGreen low
English HollyEnglish Holly((Ilex aquifoliumIlex aquifolium))
Tree 15 to 50 feet tall and Tree 15 to 50 feet tall and 15 feet wide15 feet wide
Bark smooth and grayBark smooth and gray
Leaves glossy, persistent, Leaves glossy, persistent, dark green, wavy and dark green, wavy and spinyspiny
Flowers are small and Flowers are small and whitewhite
Berries are bright red or Berries are bright red or orange and found in small orange and found in small bundles like the flowersbundles like the flowers
English HollyEnglish Holly((Ilex aquifoliumIlex aquifolium))
can form thickets of can form thickets of large, densely packed large, densely packed trees in shady forests trees in shady forests or open areasor open areas
spreads by seeds spreads by seeds eaten by birds; can eaten by birds; can establish in remote establish in remote areasareas
re-sprouts indefinitely re-sprouts indefinitely from cut stumps so from cut stumps so digging is best non-digging is best non-chemical methodchemical method
English Hawthorne (English Hawthorne (Crataegus monogynaCrataegus monogyna))
European Mountain-ash (European Mountain-ash (Sorbus aucupariaSorbus aucuparia))
European Sweet Cherry (European Sweet Cherry (PrunusPrunus aviumavium))
A small to medium A small to medium sized tree, generally to sized tree, generally to 50 feet, with a broadly 50 feet, with a broadly rounded crown rounded crown
Leaf 2 to 5 inches long Leaf 2 to 5 inches long with serrated marginwith serrated margin
Flowers showy, white, Flowers showy, white, one inch acrossone inch across
Cherries sweet, dark Cherries sweet, dark red to nearly black, 1/2 red to nearly black, 1/2 to 1 inch acrossto 1 inch across
Norway Maple (Norway Maple (Acer platanoidesAcer platanoides))
Common shade treeCommon shade tree Escaping into Seattle Escaping into Seattle
forestsforests Similar to native bigleaf Similar to native bigleaf
maple, but the leaf is maple, but the leaf is not as large or deeply not as large or deeply cutcut
Seeds spread their Seeds spread their wings wider and have wings wider and have no bristly hairsno bristly hairs
www.hort.cornell.edu
Invasive vinesInvasive vines Form dense groundcovers excluding Form dense groundcovers excluding
all native plantsall native plants Climb up and smother treesClimb up and smother trees Add weight to tree canopiesAdd weight to tree canopies
Form dense groundcovers excluding Form dense groundcovers excluding all native plantsall native plants
Climb up and smother treesClimb up and smother trees Add weight to tree canopiesAdd weight to tree canopies
English ivy Old man’s beard
English or Atlantic IvyEnglish or Atlantic Ivy((Hedera hibernica, H. helixHedera hibernica, H. helix))
Ivy leaves are evergreen, lobed, dull green, with light Ivy leaves are evergreen, lobed, dull green, with light veinsveins
Class C Noxious Weed – Control Not Required
English or Atlantic IvyEnglish or Atlantic Ivy((Hedera hibernica, H. helixHedera hibernica, H. helix))
• mature ivy mature ivy leaves are shiny leaves are shiny green and not green and not lobedlobed
• umbrella-like umbrella-like clusters of clusters of greenish-white greenish-white flowers in the fallflowers in the fall
• black, berry-like black, berry-like fruit in winter, fruit in winter, seeds mature in seeds mature in springspring
Class C Noxious Weed – Control Not
Required
Ivy mats smother understory plantsIvy mats smother understory plantsand tree seedlings - changing theand tree seedlings - changing thenatural succession patterns of forests.natural succession patterns of forests.
Ivy climbs trees, Ivy climbs trees, weighs down weighs down branches, shades branches, shades leaves, damages barkleaves, damages bark
English IvyEnglish Ivy
Class C Noxious Weed – Control Not Required
Old Man’s BeardOld Man’s Beard((Clematis vitalbaClematis vitalba))
Class C Noxious Weed – Control Not Required
Old Man’s Beard or Wild ClematisOld Man’s Beard or Wild Clematis
Old Man’s Beard covering trees at Magnuson Park
Old Man’s Beard on trees in Ravenna Park
Class C Noxious Weed – Control Not Required
Invasive ShrubsInvasive Shrubs
Form dense thickets excluding all Form dense thickets excluding all native plantsnative plants
Establish in disturbed sitesEstablish in disturbed sites Spread by birds, wind and peopleSpread by birds, wind and people
Form dense thickets excluding all Form dense thickets excluding all native plantsnative plants
Establish in disturbed sitesEstablish in disturbed sites Spread by birds, wind and peopleSpread by birds, wind and people
Controlling Scotch broom with weed wrenches at Marymoor Park
Class C Noxious Weed – Control Not Required
Cotoneaster ShrubsCotoneaster Shrubs
Thornless shrub up to 15" Thornless shrub up to 15" tall with arching branchestall with arching branches
Small leaves white-hairy Small leaves white-hairy underneathunderneath
Little white flowers and Little white flowers and dull red fruitsdull red fruits
Colorful fruits attractive to Colorful fruits attractive to birds leading to easy birds leading to easy spread and invasivenessspread and invasiveness
Increasingly common in Increasingly common in Seattle’s forestsSeattle’s forests
Invasive Perennials and Invasive Perennials and GroundcoversGroundcovers
Fast-growing invasives push out native Fast-growing invasives push out native wildflowers and groundcover specieswildflowers and groundcover species
Tall perennials out-compete even shrubs and Tall perennials out-compete even shrubs and small trees especially on streamssmall trees especially on streams
Often escapees from gardens or spreading from Often escapees from gardens or spreading from yard waste dumpsyard waste dumps
Can grow to 10 feet tall in one seasonCan grow to 10 feet tall in one season
Class B Noxious Weed
Policeman’s helmet spreads along creeks Policeman’s helmet spreads along creeks and out-competes and crowds out other and out-competes and crowds out other plantsplants
Policeman’s Helmet (Impatiens glandulifera) Class B Noxious
Weed
Policeman’s Helmet (Impatiens glandulifera)Policeman’s Helmet (Impatiens glandulifera)Class B Noxious
Typical stand of Bohemian knotweed with stiffly upright male flower clusters
Class B Noxious Weed – Control Not Required
Knotweed rapidly spreads along rivers as Knotweed rapidly spreads along rivers as fragments get moved by floods and grow into new fragments get moved by floods and grow into new clones downriverclones downriver
Knotweed Invasion on RiversKnotweed Invasion on Rivers
Class B Noxious Weed – Control Not Required
Despite knotweed’s large rhizome mass, it provides poor erosion control
Herb Robert (a.k.a. Stinky Bob)Herb Robert (a.k.a. Stinky Bob)
Class C Noxious Weed – Control Not Required
Herb Robert (a.k.a. Stinky Bob)Herb Robert (a.k.a. Stinky Bob)((Geranium robertianumGeranium robertianum))
Shallow roots make this plant easy to pull but seeds germinate all season so repeat visits to the same location are needed.
Small yellow mint-type Small yellow mint-type flowers in leaf axilsflowers in leaf axils Slivery markings on leaves of this popular garden Slivery markings on leaves of this popular garden
plant make it easy to spot invading into shady forestsplant make it easy to spot invading into shady forests
Proposed Class C Noxious Weed – Control Not Required
Poison Hemlock (Poison Hemlock (Conium maculatumConium maculatum))Class C Noxious Weed – Control Not Required
Aquatic WeedsAquatic Weeds
Choke out native water plantsChoke out native water plants Reduce fish and wildlife habitat value of Reduce fish and wildlife habitat value of
streams and lakesstreams and lakes Endanger swimmers and boatersEndanger swimmers and boaters Highly costly to manage once established Highly costly to manage once established
and almost impossible to eradicateand almost impossible to eradicate
Common Reed (Common Reed (Phragmites australisPhragmites australis))
•Large perennial grassLarge perennial grass
•Freshwater or brackish waterFreshwater or brackish water•Can grow to 12 feet tallCan grow to 12 feet tall•Leaf sheath looseLeaf sheath loose•Reproduction mostly by rhizomesReproduction mostly by rhizomes
Common Reed (Common Reed (Phragmites australisPhragmites australis))
Creeping rhizomes and stolons help Creeping rhizomes and stolons help this plant spread along waterways and this plant spread along waterways and form large clonesform large clones
Class C Noxious Weed – County-select
Eek! What Can We Do?Eek! What Can We Do?
First, Start at HomeFirst, Start at Home
Learn to recognize & eliminate noxious Learn to recognize & eliminate noxious weeds before they establishweeds before they establish
Choose non-invasive species for Choose non-invasive species for landscapes & gardenslandscapes & gardens
Control seed production Control seed production at a minimumat a minimum Replant with appropriate speciesReplant with appropriate species Dispose of noxious weeds properlyDispose of noxious weeds properly Check vehicles, clothing and equipmentCheck vehicles, clothing and equipment
Control Methods for Noxious Control Methods for Noxious Weeds ManagementWeeds Management
ManualManual
MechanicalMechanical
ChemicalChemical
BiologicalBiological
Control Chart by Minnesota Sea-Grant
•Pull seedlings and young plants when small, Pull seedlings and young plants when small, before root systems fully developbefore root systems fully develop
•Remove as much of the root as possibleRemove as much of the root as possible
•Limit disturbance and be sure to follow-upLimit disturbance and be sure to follow-up
Pulling and bagging tansy ragwort
Digging purple loosestrife
Manual control of Scotch broom
Manual ControlManual Control
•Useful to reduce size, seed production and to starve Useful to reduce size, seed production and to starve roots, especially when plants cover large areasroots, especially when plants cover large areas
•Weeds will resprout after mowing and can be spread Weeds will resprout after mowing and can be spread on equipment if not carefulon equipment if not careful
•Best results when combined with manual controlBest results when combined with manual control
Himalayan Blackberry can be mowed to remove brambles
Mechanical ControlMechanical Control
Safety:Safety:•Use with caution, protect skin and eyesUse with caution, protect skin and eyes
•Always follow the directions on the labelAlways follow the directions on the label
•Prevent drift into water, other plants, etcPrevent drift into water, other plants, etc
Applications:Applications:•Spot treatments, target the weed and Spot treatments, target the weed and avoid injury to desirable plantsavoid injury to desirable plants
•Incorporate other treatment methodsIncorporate other treatment methods
•Choose the least harmful herbicide that is Choose the least harmful herbicide that is appropriate for the weed and the siteappropriate for the weed and the site
Finally, Disposal and Follow upFinally, Disposal and Follow up
DisposalDisposal Remove flowers & seeds – bag Remove flowers & seeds – bag
and send to landfill or burnand send to landfill or burn Composting – use for common Composting – use for common
invasives, not for noxious weedsinvasives, not for noxious weeds On-site composting vs. clean On-site composting vs. clean
green yard wastegreen yard waste
MonitorMonitor The second and third year are The second and third year are
crucial for effective weed controlcrucial for effective weed control
Next Step,Next Step,Become a Weed WarriorBecome a Weed Warrior
Watch for new plant invadersWatch for new plant invaders Volunteer at invasive removal work parties Volunteer at invasive removal work parties
and stewardship eventsand stewardship events Organize your friends, co-workers, and Organize your friends, co-workers, and
neighbors to “adopt” a park or natural areaneighbors to “adopt” a park or natural area Spread the word on neighborhood bullies!Spread the word on neighborhood bullies!
Local Contacts for VolunteeringLocal Contacts for Volunteering King County Parks and Open SpaceKing County Parks and Open Space
Volunteer Coordinator: Tina Miller, 206-296-2990Volunteer Coordinator: Tina Miller, 206-296-2990 Calendar: Calendar: http://http://dnr.metrokc.gov/wlr/pi/calendar.htmdnr.metrokc.gov/wlr/pi/calendar.htm
Watershed Stewardship DirectoryWatershed Stewardship Directory groups and agencies helping to preserve and restore groups and agencies helping to preserve and restore
King County's watershedsKing County's watersheds http://http://dnr.metrokc.gov/wlr/wsdir/index.cfmdnr.metrokc.gov/wlr/wsdir/index.cfm
Seattle Urban Forests Seattle Urban Forests Contact: Peter Noonan, (206)233-5019Contact: Peter Noonan, (206)233-5019
Seattle ParksSeattle Parks http://http://www.seattle.gov/parks/volunteers/index.htmwww.seattle.gov/parks/volunteers/index.htm
Seattle CreeksSeattle Creeks Contact: Bob Spencer, (206) 684-4163Contact: Bob Spencer, (206) 684-4163
Sign up for newsletter at:Sign up for newsletter at:www.seattleurbannature.orgwww.seattleurbannature.org
It is a free, quarterly publication sent out by It is a free, quarterly publication sent out by e-mail only. Each issue features e-mail only. Each issue features information about SUN research in information about SUN research in Seattle’s forests and our current Seattle’s forests and our current community projects.community projects.
King County Noxious Weed ProgramKing County Noxious Weed Program
6 year-round staff and 8 6 year-round staff and 8 seasonal weed seasonal weed specialistsspecialists
Goal is to prevent and Goal is to prevent and reduce the economic, reduce the economic, environmental and social environmental and social impacts of noxious weeds impacts of noxious weeds
Weed surveys, education Weed surveys, education and outreach, landowner and outreach, landowner contact, site specific contact, site specific control optionscontrol options
King County Noxious Weed King County Noxious Weed Program StaffProgram Staff
Program Manager: Program Manager: Steve BurkeSteve Burke Education Coordinator: Education Coordinator: Sasha ShawSasha Shaw Admin Specialist: Admin Specialist: Suzanne RoweSuzanne Rowe State Lands Coordinator: State Lands Coordinator: Sean MacDougallSean MacDougall County Lands Coordinator: County Lands Coordinator: Roy BrunskillRoy Brunskill Aquatic Weed Specialist:Aquatic Weed Specialist: Katie MessickKatie Messick Seasonal Weed Specialists:Seasonal Weed Specialists:
Amy Yahnke, Dennis Chambreau, Trish MacLaren, Amy Yahnke, Dennis Chambreau, Trish MacLaren, Sarah Baker, Monica Walker, Karen Peterson, Maria Sarah Baker, Monica Walker, Karen Peterson, Maria Winkler, Frances LuceroWinkler, Frances Lucero
Contact us at 206-296-0290 or Contact us at 206-296-0290 or [email protected]@metrokc.gov
King County Noxious Weed King County Noxious Weed Control Program WebsiteControl Program Website
http://dnr.metrokc.gov/weedsWeed Photo Page:
Search by Common Name or Latin Name
Click thumbnail picture of plant
Sasha ShawSasha Shaw King County Noxious Weed ProgramKing County Noxious Weed Program
201 South Jackson St, Suite 600201 South Jackson St, Suite 600Seattle, WA 98104Seattle, WA 98104