A Lightspeed Invasion
There is a thorny vine that every gardener should be aware of: Mile-a-Minute Vine (Persicaria perfoliata), and this is no misnomer; it is on a supervillain level of “garden evil" due to its volatile and aggressive nature. On average human hair will grow at a rate of 15cm (6in) a year, which feels like a normal rate of growth and is hardly noticeable on a daily basis, this vine grows just as far but on a daily basis. One can only imagine the devastation it has caused on ecosystems in the northeastern quadrant of the USA. Suffice to say Mile-a-Minute gives a new meaning to “a creeping doom”, our next invasive plant highlight is not a vine to underestimate.
The problem began in the early 20th century. While many of the invasive species on the continental US arrived as ornamental species, Mile-a-Minute made its way across the Pacific to Pennsylvania by accident. However, much like all other invasive species this is where the dissimilarities end. This vine can swallow a forest over the course of a summer, reproduce and spread at an unbelievable rate, and survive in colder climates. Of course as
the name suggests this vine will spread at an almost lightspeed rate if left unperturbed. It grows over all native species, denying them light and space, and chokes the ecosystems it infects. The image you see here exemplifies the desolation it causes. The second weapon it employs is the resilience of its seeds. Found in their fruits these seeds can float in rivers waiting to be deposited for up to a week and can be passed by birds who eat the berries and take root with little to no effort. The vines themselves need no pollinators and will produce seed bearing fruit for nearly five months (June to October). Needless to say this plant is a formidable force.
Identifying this plant can be relatively easy depending on how advanced the infestation is. One must look for a sea of triangular leaves on barbed vines, the leaves will grow to an average of 2.5-7 cm (1-3 in) and the vines will have a woody gray color. While its flowers are relatively inconspicuous one can use its berries as identifying markers. Similarly to its cousin the Porcelain Berry the Mile-a-Minute vine will produce purply blue berries that grow to the size of small grapes. They are produced by small circular shaped leaves called ocreas which are found every several inches on the stem and contain future flowers inside.
While the possibility of the flowers opening is not guaranteed, the Mile-a-Minute vine will self-pollinate and produce fruits that are blue. These berries are one of its primary methods of reproduction and must be removed before they fully mature to avoid further spread.
Removing the infestation should be equally easy to enact, a sort of balance to how easily it will kill native species. Removing the young vines in late-spring to early summer before fruiting is one of the most effective methods. It is not recommended to use herbicides for eradication as the native species struggling to survive beneath will be adversely affected while only achieving mediocre results. Other sources recommend repeated mowing or weed whacking to prevent growth and spread however this method does require careful monitoring. As this plant is not an ornamental species and was instead brought over as a contaminate of holly seeds there are no recommended alternatives to plant other than existing native species. If you are uncertain about what to place in its stead we always recommend consulting google and your loca
l nursery for specialized options.
By adding to our list of invasive species, we intend to bring awareness to as many species that plague their ecosystems. The Mile-a-Minute vine is most certainly a grave threat to many fields and the woodlands that border them. The best course of action that any individual or entity can take is to remain vigilant and committed to ensuring biodiversity for a more diverse tomorrow.