Transcript Japanese Knotweed

Japanese Knotweed
By Linda Tucker
Polygonum cupsidatum
 Also called Fallopia joponica
 Buckwheat family (Polygonaceae)
 Common names:
 Japanese Knotweed
 Mexican Bamboo
 Chinese Chokeweed
 Native to eastern Asia
How Did it Get Here?
 First introduced from Japan into the
United Kingdom in 1825
 Was introduced to the United States from
the U.K. in the late 1800s
 Introduced as an ornamental plant
 In recent history, heavily planted at mine
reclamation sites in PA
About the Plant
 Perennial
 Grows between 3 and 10 feet high
 Stems are reddish green, jointed, and
hollow
 Broad, alternate leaves
 Flowers: small and greenish white and
grow in spikes
What Does It Look Like?
Where is it Found?
 Moist environments, such as stream
banks, islands, and wetlands
 Also found along roadsides and railroads
 Can live in open sun or partial shade
 Can tolerate harsh conditions such as
high temperatures, high salinity,
droughts, and floods
Distribution
How Does it Spread?
 Reproduces through
two methods:
 Seeds
 Fragmentation of the
rhizome
 Rhizome can be 40
to 60 feet in length
Ecological Impacts
 Japanese knotweed grows quickly and
densely
 Crowds out native plants and limits
biodiversity
 Causes stream banks to be less stable
and susceptible to erosion during floods
Urban Impacts
How to Get Rid of It
 Eradication is very difficult
 If it is cut, it will grow back due to the rhizome
 It can be dug up, but any remaining rhizome
can grow back and you can actually spread the
rhizome this way
 Herbicides such as Glyphosate and Triclopyr
can be used effectively in combination with
cutting
How to Prevent Spreading
 Don’t plant Japanese Knotweed
 Wash your shoes before entering and
after leaving natural areas to remove
seeds
 Do not dig up the rhizome, as you may
accidentally spread rhizome fragments
Some Positive Qualities
 Excellent source of vitamins A and C
 Good source of resveratrol, which can
lower bad cholesterol and reduce the risk
of heart attack
 Tastes similar to rhubarb and can be
used in baked goods, soups,
marmalades, or just steamed and eaten
References
 http://www.in.gov/dnr/files/Japanese_Knotweed
.pdf
 http://dnr.wi.gov/invasives/publications/pdfs/jap
anese_knotweed_control.pdf
 http://www.forestpests.org/acrobat/jknot.pdf
 http://www.wildmanstevebrill.com/Plants.Folder
/Knotweed.html
 http://www.dcnr.state.pa.us/forestry/invasivetut
orial/japanese_knotweed.htm
Questions or Comments?