Download - Japanese Knotweed
Japanese KnotweedJapanese Knotweed
By Linda TuckerBy Linda Tucker
Polygonum cupsidatumPolygonum cupsidatum
Also called Also called Fallopia joponicaFallopia joponica Buckwheat family (Buckwheat family (PolygonaceaePolygonaceae)) Common names:Common names:
Japanese KnotweedJapanese Knotweed Mexican BambooMexican Bamboo Chinese ChokeweedChinese Chokeweed
Native to eastern AsiaNative to eastern Asia
How Did it Get Here?How Did it Get Here?
First introduced from Japan into the First introduced from Japan into the United Kingdom in 1825United Kingdom in 1825
Was introduced to the United States from Was introduced to the United States from the U.K. in the late 1800sthe U.K. in the late 1800s
Introduced as an ornamental plantIntroduced as an ornamental plant In recent history, heavily planted at mine In recent history, heavily planted at mine
reclamation sites in PAreclamation sites in PA
About the PlantAbout the Plant
PerennialPerennial Grows between 3 and 10 feet highGrows between 3 and 10 feet high Stems are reddish green, jointed, and Stems are reddish green, jointed, and
hollowhollow Broad, alternate leavesBroad, alternate leaves Flowers: small and greenish white and Flowers: small and greenish white and
grow in spikesgrow in spikes
What Does It Look Like?What Does It Look Like?
Where is it Found?Where is it Found?
Moist environments, such as stream Moist environments, such as stream banks, islands, and wetlandsbanks, islands, and wetlands
Also found along roadsides and railroadsAlso found along roadsides and railroads Can live in open sun or partial shadeCan live in open sun or partial shade Can tolerate harsh conditions such as Can tolerate harsh conditions such as
high temperatures, high salinity, high temperatures, high salinity, droughts, and floodsdroughts, and floods
DistributionDistribution
How Does it Spread?How Does it Spread?
Reproduces through Reproduces through two methods:two methods: SeedsSeeds Fragmentation of the Fragmentation of the
rhizomerhizome
Rhizome can be 40 Rhizome can be 40 to 60 feet in lengthto 60 feet in length
Ecological ImpactsEcological Impacts
Japanese knotweed grows quickly and Japanese knotweed grows quickly and denselydensely
Crowds out native plants and limits Crowds out native plants and limits biodiversitybiodiversity
Causes stream banks to be less stable Causes stream banks to be less stable and susceptible to erosion during floodsand susceptible to erosion during floods
Urban ImpactsUrban Impacts
How to Get Rid of ItHow to Get Rid of It
Eradication is very difficultEradication is very difficult If it is cut, it will grow back due to the rhizomeIf it is cut, it will grow back due to the rhizome It can be dug up, but any remaining rhizome It can be dug up, but any remaining rhizome
can grow back and you can actually spread the can grow back and you can actually spread the rhizome this wayrhizome this way
Herbicides such as Glyphosate and Triclopyr Herbicides such as Glyphosate and Triclopyr can be used effectively in combination with can be used effectively in combination with cuttingcutting
How to Prevent How to Prevent SpreadingSpreading
Don’t plant Japanese KnotweedDon’t plant Japanese Knotweed Wash your shoes before entering and Wash your shoes before entering and
after leaving natural areas to remove after leaving natural areas to remove seedsseeds
Do not dig up the rhizome, as you may Do not dig up the rhizome, as you may accidentally spread rhizome fragmentsaccidentally spread rhizome fragments
Some Positive QualitiesSome Positive Qualities
Excellent source of vitamins A and CExcellent source of vitamins A and C Good source of resveratrol, which can Good source of resveratrol, which can
lower bad cholesterol and reduce the risk lower bad cholesterol and reduce the risk of heart attackof heart attack
Tastes similar to rhubarb and can be Tastes similar to rhubarb and can be used in baked goods, soups, used in baked goods, soups, marmalades, or just steamed and eatenmarmalades, or just steamed and eaten
ReferencesReferences
http://www.in.gov/dnr/files/Japanese_Knotweedhttp://www.in.gov/dnr/files/Japanese_Knotweed.pdf.pdf
http://dnr.wi.gov/invasives/publications/pdfs/http://dnr.wi.gov/invasives/publications/pdfs/japanese_knotweed_control.pdfjapanese_knotweed_control.pdf
http://www.forestpests.org/acrobat/jknot.pdfhttp://www.forestpests.org/acrobat/jknot.pdf http://www.wildmanstevebrill.com/http://www.wildmanstevebrill.com/
Plants.Folder/Knotweed.htmlPlants.Folder/Knotweed.html http://www.dcnr.state.pa.us/forestry/http://www.dcnr.state.pa.us/forestry/
invasivetutorial/japanese_knotweed.htminvasivetutorial/japanese_knotweed.htm
Questions or Comments?Questions or Comments?