Mile-A-Minute Weed

mile a minute weed

(Persicaria perfoliata)

Other names: Asiatic tearthumb 
*Detected in Michigan*
WATCH LIST

WHAT TO LOOK FOR
  • Fast-growing annual vine with leaves shaped like equilateral triangles. 
  • Narrow, delicate, green or red stems.
  • Recurved barbs on stems and undersides of leaf blades.
  • Alternate, light green leaves, 1”-3” wide. 
  • Individual, round leaves (ocreae) encircle the stem below the flower/fruit spike.
  • Small white flowers in early summer.
  • Spikes of pea-sized blue fruit appear in July. 

A cluster of mile-a-minute weed vine showing triangular leaves and fruit spikes.

 

 

 

 

 

 

 

Mile-a-minute weed leaves are light green and triangular.

Mile-a-minute weed stems and leaves showing recurved barbs.

 

 

 

 

 

 

 

 

Small, curved barbs line the stem and leaf blade.

Mile-a-minute weed's spike of blue, pea-sized fruit.

 

 

 

 

 

 

 

 

Small, blue berries grow in spikes above circular leaves that wrap the stem.

mile a minute weed

Mile-a-minute weed can overtake and smother trees and shrubs.

Photos courtesy of Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

REPORT THIS SPECIES

If you see mile-a-minute weed, take one or more photos, make note of the location, date and time of the observation, and report to:

ABOUT THIS SPECIES

Habitat: This herbaceous, annual, trailing vine colonizes open and disturbed areas with a preference for very wet soil. Typical infestation areas include stream banks, open space, roadsides, forest edges, and fence lines. Mile-a-minute weed thrives with abundant sunlight and uses its recurved barbs to attach to and climb over other plants.

Native Range: India to Eastern Asia, China, and islands from Japan to the Philippines

U.S. Distribution: Reported in Connecticut, Delaware, Massachusetts, Maryland, Michigan, Mississippi, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Virginia, West Virginia, and Washington.

Michigan Distribution: Identified in Calhoun County. 

Michigan Status: Mile-a-minute weed is on Michigan’s watch list.

Local Concern: Mile-a-minute weed can grow up to 25’ in six to eight weeks.  Dense, prickly thickets overtake native vegetation. Christmas tree farms, orchards, reforestation and restoration areas are at risk because of the vine’s propensity to smother tree and plant seedlings. Seeds may survive in the soil for up to six years.

Means of Introduction or Spread: Each fruit contains a single seed, and vines can produce up to 3,500 seeds per year. Fruits are eaten by birds, deer and small mammals which can spread seeds miles away from the original plant. 

Control: As an annual, mile-a-minute weed can be controlled by regular tilling or mowing to prevent flowering or seeding. Young and mature plants can be removed manually before fruits ripen. Double bag all plant material and allow to decompose in sunlight for several days before removing waste to a landfill or incinerator. Infested areas should be monitored regularly for regrowth.

MORE INFORMATION:

Mile-a-minute Weed Invasive Species Alert - Printable PDF