By Britt Slattery, USFWS
Scientific name: Polygonum perfoliatum
Mile-a-minute is an exotic annual vine that can grow up to 14 or 15 feet in height. Its leaves are green and triangular shaped. The stem has downward facing barbs, that are also present on the undersides of the leaves. Flowers are self-pollinating. The fruits average around pea size. They are blue in color which, in turn, make them very attractive to birds, and other wildlife. The plant has been known to grow over 5 inches in a day.
Mile-a-minute has a wide range of suitable habitats. Its four known locations in the park are Shop Run, Hull School Trail,
Common names include Mile-a-minute, Asiatic Tearthumb, Ishimikawa, Minuteweed, and Devils Tail.
Mile-a-minute is known to out compete natives for resources. The plant grows very fast, and will absorb nutrients quicker than its competitors. It will cover the native plants from available sunlight, which doesn’t allow them to photosynthesize. This in turn puts stress on the sun-loving natives and eventually kills them.
There are a couple strategies taken by the National Park Service to prevent further growth. The most effective is to pull the plants by hand. This has been attempted at all known sites in the park. This is effective but very time consuming.
Weed AsideTM Weed Killer has been sprayed on the more overgrown sites in the park. It is a herbicidal soap solution, which selectively kills weeds, including mile-a-minute (Gurneys, 2005). An effort is made to control mile-a-minute in the spring so the it doesn’t have the chance to produce seeds.
References and Links:
Mountain, W.L. 1989. Mile-a-minute update – distribution, biology and control suggestions in Regulatory Horticulture 15(2)21 – 24.
Further information can be found:
Integrated Taxonomic Information System (ITIS) Report U.S. Department of Agriculture.
Germplasm Resource Information Network database which is sponsored by the Agricultural Research Service, U.S. Department of Agriculture.
PLANTS National Database, a website supported by the Natural Resource Conservation Service.
Did You Know?
The small circular pits (Opferkessels) often found in the rocks of Shenandoah National Park’s cliffs and summits are formed by standing water.