University of Missouri Extension

IPM1021, New December 2003

Vine Weeds of Missouri

Japanese knotweed 
Japanese knotweed

Growth habit

  • Perennial

Other names

  • Japanese bamboo
  • Mexican bamboo

Origin

  • Eastern Asia

Control classification

  • Difficult

Note

  • Before using any any herbicide, read and follow directions on the label accompanying that product. Reference to specific trade names does not imply endorsement by the University of Missouri; discrimination is not intended against similar products.

Japanese knotweed (Polygonum cuspidatum)

Japanese knotweed is an escaped ornamental plant that can quickly form dense clumps in which no other vegetation can survive. The plant regenerates from rhizomes and reaches heights up to 6 feet, which gives it a shrublike appearance. Some refer to the weed as Japanese or Mexican bamboo because of its hollow and jointed stems.

Like other members of the Polygonaceae (smartweed) family, papery sheathlike ocreas are found along its stems where the leaves join. Leaves occur alternately along the reddish stems and range in size from 3 to 6 inches in length; their shape is broadly ovate. Leaf veins have a distinct red color. Flowers are produced in clusters in the leaf axils and are a white color.

After frost, the stems of the plant persist through the winter.
 

 

Wild thing
 

IPM1021 Vine Weeds of Missouri | University of Missouri Extension

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