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Persicaria perfoliata (Polygonum perfoliatum)

Biological Category 
Plants
Species Type 
Vine
NY Invasiveness Rank 
Very High
LHPrism Status 
Tier 3 - Established
Key Characteristics 
Leaf
Lime-green leaves shaped as an equilateral triangle with stem attached in the middle on the under-side of the leaf.
Fruit
Small blue to purple berry arranged in a grape-like cluster at the tips of stems, ripening July-October.
Stem
Curved prickles along stem and leaf stalks. Stems have joints with a round leaf-like stipule (see photo above)

Vertical Tabs

Description 

Mile-a-minute is a member of the Buckwheat family (Polygonaceae). It is a bright green, spiny, herbaceous annual vine capable of forming dense vegetative mats. Its bright blue berries, emerging towards the end of the summer, are perhaps the most conspicuous feature of the species.  These fruits are arranged in long clusters in the axils of the leaves and contain a single, black, glossy seed. (3) Mile-a-minute is also highly visible in spring when broad, triangular, lime-green leaves begin to clamber over surrounding vegetation. (5). These leaves are distinctively triangular, hairless, and thin, with prickles on the midrib on the leaf’s underside. Sheathing ocrea, a saucer-shaped leaf-like structure, surround the stems at leaf nodes and are a good diagnostic feature of the species. (5) Mile-a-minute's flowers are inconspicuous and lack any showy petals. Arranged on a spike up to an inch long, flowers are found in the axils of the upper leaves, or at the terminal point of the plant’s vine. (5)

Introduction History 
Mile-a-minute was first introduced to North America with ship ballast, in Oregon, in the 1830s. It did not establish permanent populations until it arrived inadvertently at a nursery in York County, PA, in the 1930s. The species is now extant in at least 11 states. (3, 4)
Ecology and Habitat 
Mile-a-minute will invade any open, sunny habitat and is commonly found along railroads, powerlines, woodland edges, riparian areas, and low meadows. The species prefers moist, well-lit habitats but can colonize drier, shadier sites too. Seed production and survivorship will be lower in these areas. (3)
Reproduction and Phenology 
Mile-a-minute seed production is highly variable and appears to be significantly impacted by light levels. A single plant may produce seven to forty seeds per year. The species is self-fertile and although bees have been observed visiting flowers, fruit production is generally the result of self-pollination. (6) Fruits can remain buoyant for over a week and are transported vast distances by birds, particularly migratory species. Seeds are known to remain viable at rates of 95% buried in the soil for at least three years. (2) Vectors include birds, small mammals, water and horticultural trade (3)
Impacts of this species 

A spiny, herbaceous, annual vine, mile-a-minute gets its name from the celerity with which it grows. Capable of impacting the vegetative communities it invades from the canopy level down, mile-a-minute’s dense, smothering growth blocks light, limiting other plants’ ability to photosynthesize and germinate. In fact, mile-a-minute mats may be so thick they kill other thicket or mat-forming invasives such as Japanese honeysuckle. (2)

Management Methods 

Biological Control
The Asian weevil (Rhinoncomimus latipes) has established populations throughout the Mid-Atlantic and New York and appears to impact Mile-a-minute’s competitive ability by decreasing annual growth and flowering. (3) For more information on biological control, please visit our mile-a-minute biocontrol website.

Manual or Mechanical Control
Pulling / Digging Up: Pulling by hand is an effective method of control for smaller populations of mile a minute. Gloves must be worn if undertaking this method due to the species’ sharp spines. 

Mowing: Regular mowing, particularly in open areas will reduce or halt fruiting. (7)

Girdling: not applicable

Prescribed Fire: Little information is available on the efficacy of fire as a management tool for mile-a-minute. However, as a shallowly rooted annual vine it is likely a controlled burn would kill the vine.
    
Torching: Anecdotal evidence suggests torching may be a successful control method when done early in the season. 

Prescribed Grazing: Not applicable

Soil Tilling: Tilling is generally not appropriate in the fragile, often moist soils mile-a-minute colonizes. However, this management strategy will eradicate infestations if performed before seed set. (2)

Mulching: Mulching may help reduce the seed bank and cover bare ground after infestations have been controlled via spraying and or pulling, however, this will also reduce the reestablishment of other, native vegetation in the area, too

Solarization: No information available

Hot Foam Spray: No information available

Chemical Control
The pesticide application rates and usage herein are recommendations based on research and interviews with land managers.  When considering the use of pesticides, it is your responsibility to fully understand the laws, regulations and best practices required to apply pesticides in a responsible manner.  At times, the pest you seek to treat may not be on a pesticide label, requiring a 2ee exemption from NYSDEC.  Always thoroughly read the label of any pesticide and consult the NYSDEC or a licensed pesticide applicator with questions.

Foliar Spray: A 1-2% solution of glyphosate is effective at managing mile-a-minute, although repeat applications may be necessary. Infestations managed in this way should be revisited in 2-3 weeks to monitor for regrowth. Always read and follow all instructions on the herbicide label. (8)

Cut Stump: Not applicable

Basal Bark: Not applicable

Hack-And-Squirt

Stem Injection: Not applicable

Pre-Emergent Spray: Not applicable

Summary of Best Managment Practices 

General management overview and recommendation
As with any other invasive infestation complex, infestations of mile-a-minute are best managed via a combination of mechanical and chemical means.  Small seedlings and plants can be hand pulled while larger shrubs must be sprayed to attain good control. All managed infestations should be monitored to ensure exhaustion of the seed bank for at least three years and to prevent reinvasion from nearby populations. Any new seedlings can be hand pulled or sprayed. 

Post treatment monitoring
Any infestations managed by chemical means must be revisited in 2-3 weeks to check for treatment efficacy.  Due to the long-distance dispersal mechanisms of mile-a-minute, managed infestations must be checked for reinvasion, particularly if the site is down river from known seed sources. 

Disposal Methods
Waste material can be burned or composted so long as management was completed prior to seed set. Any fruit must be bagged and disposed of.