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30 MILE-A-MINUTE WEED (Persicaria perfoliata) PLANT DESCRIPTION Mile-a-minute weed, also known as Devil's tearthumb, is an aggressive, fast-growing broadleaf summer annual vine. It can be seen in the summer as a climbing or spreading vine capable of taking over large areas. Mile-a-minute weed grows very fast and can quickly grow into thick mats covering the ground or climbing over other vegetation. LEAF: The leaf is light green, small, and triangular with straight edges. The underside of the leaf and leaf stem are armed with downward-pointing sharp spines. Mile-a-minute weed vines have unique cup-like leaves encircling the stem. STEM: The stem is very slender but distinctly square shaped and armed with sharp downward pointing spines. FLOWER: The flowers are small with a whitish pink color and are produced in an upward pointing cluster from within the cup-like leaf, eventually developing berries. FRUIT/SEED: Mile-a-minute weed fruit is formed in erect, tightly-arranged clusters of green berries that ripen to a waxy dark blue. REPRODUCTION: The seeds of mile-a-minute weed function as the primary means of reproduction. Seed can be transported by water and wildlife. Seed production can vary based on site conditions and can stay viable for several years. WHY IT IS NOXIOUS: Mile-a-minute weed poses a significant threat to wet habitats due to its ability to outcompete native vegetation. Due to rapid growth this aggressive weed can also cause significant maintenance concerns if left uncontrolled. SEASONAL IDENTIFICATION WHEN TO FIND: Look from late spring to fall near waterways for masses of vines with triangular leaves and blue berry clusters. SPRING IDENTIFICATION = MODERATE Young mile-a-minute weed has triangular leaves with straight edges. In spring, it also has distinctive, cup-like leaves that wrap the stem at nodes where branches occur. The thin stems and undersides of leaves are armed with downward pointing sharp spines. SUMMER IDENTIFICATION = EASY From summer to fall, mile-a-minute weed can flower. Its small whitish pink flowers form in spike clusters of 10–15 blossoms. Mile-a-minute weed grows very quickly and forms dense mats or may grow on top of other vegetation. FALL IDENTIFICATION = EASY From late summer until the first frost, mile-a-minute weed will have clusters of bright blue berries. This makes identification very easy. The clusters form above the cup-like leaves on the stem. WINTER IDENTIFICATION = EASY TO MODERATE In winter months, brown to grey, slender, narrow stems may remain. The stems form dense thickets and retain sharp spines. SIMILAR-LOOKING SPECIES ARROWLEAF TEARTHUMB (Persicaria sagittara) has a similar squared stem with many small spines. The leaves are narrow and shaped like an elongated heart. HALBERDLEAF TEARTHUMB (Persicaria arifolia) has a similar squared stem with many small spines. The leaves are wide and long, and shaped like a spear head. SAW GREENBRIER (Smilax bonanox) is also a climbing vine but it has triangle leaves that have wide, rounded corners and almost lobed edges. The stem has large, stout, flattened spines. LOW HIGH ohio distribution roadside distribution growth seeds ability to dominate difficulty of control WHERE TO FIND: Mile-a-minute weed is not prevalent in Ohio but has been observed along the Ohio River. Mile-a-minute weed requires adequate moisture to germinate, so look near waterways in full sun areas. Mile- a-minute weed can climb over all other vegetation, including trees, and has the ability to form large dense mats. CONTROL METHODS: MECHANICAL: Hand pull young plants before spines harden, or wear gloves to prevent getting pricked. Mow to reduce seed production if accessible. CHEMICAL: Broadcast pre-emergent herbicide to soils of infested areas in spring before seeds germinate. Make directed foliar applications to young mile-a-minute weed with non-selective herbicides in spring to summer. CULTURAL: Avoid creating disturbance to existing desirable plant community. RECOMMENDATION SUMMARY: Mile-a-minute weed is an aggressive, fast-growing summer annual vine that can overtake desirable vegetation and trees. Mile-a-minute weed grows rapidly throughout the growing season, so it is important to treat early. Chemical control is the best option for this weed. Foliar-applied herbicides may provide the best control but can cause off- target damage to plants that mile-a- minute weed has overtaken. If a large colony produces seed, prevent future germination by making pre-emergent herbicide applications to soil in spring before seeds germinate. Follow up with directed foliar herbicide applications to address any survivors. Avoid disturbance to surrounding desirable plant community in order to limit the spread of this weed. Mowing will have little effect on mile- a-minute weed but can reduce seed production. When hand pulling, gloves are recommended to avoid injury from the spines. Failure to control mile-a- minute weed will allow this fast-growing, aggressive vine to produce seeds that can be spread by wildlife and waterways, creating major ecological and maintenance concerns. summer annual RIVM LEVEL OF CONCERN

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