INVASIVE SPECIES THROUGHOUT MICHIGAN | PRIVET

Crisp, frosty mornings mean falls finally here and people are heading out to the woods.  The leaves are falling, which means it’s a great time to spot nonnative plants that bloom later in the year, like privet.  Privet refers to any number of shrubs or trees in the genus Ligustrum, which has over 50 species in the genus that are native to the old world.  Currently all nine species of privet dispersed mostly throughout the Southeastern portion of the United States are considered invasive species.

The first species of privet was introduced to North America in the 1700’s as an ornamental shrub,  often used for hedges or foliage in gardens.  It is a native to Europe and North Africa and managed to escape cultivation and colonize most of the worldly the 1900’s.  Privet can be most commonly found in areas where there is disturbed soil, typically along fence rows, old fields, forest edges, and ditches.  It thrives especially well in riparian forests, which is typical throughout most of the southeastern  United States.

Privet makes such a successful invasive because of its ability to out-compete native vegetation, due to its ability to adapt to different light conditions so well.  In low light environments, privet is able to produce fewer and larger ramets than its competitors. The larger ramets make privet more “tree-like” making it better competitor to its shrub-like counterparts.  Privet also has the capability of reproducing both sexually and asexually.  During sexual reproduction, privet produces seeds, that are easily dispersed through wind and by animals.  The seeds can colonize rapidly in disturbed soil, such as abandoned agricultural land, land affected by fire, forest clearings, erosion on river banks, and so forth.  It’s ability to mature quickly shortens generation cycles making dispersal even easier and further.  The fruits are small, lustrous, black, berry-like drupes that ripen in September and persist on the shrub through winter. Making now a great time to observe and record locations of existence!

One reason privet is so invasive in the United States is because it has few native shrub competitors. Most of the Lower Peninsula has encountered some form of privet, which forms dense thickets which are chocking out our native species. So when you’re out in the woods this season, keep your eyes open for privet.  Monitor sunny, disturbed, grasslands and meadows located in the forest and the woodland edges.  Remember it retains its fruit and leaves late into the fall.  Hand pulling small plants is easy and works efficiently!

This article is part of the ongoing series on invasive species funded in part with funds from the Michigan Invasive Species Grant Program through the Department of Natural Resources, Environmental Quality, and Agriculture and Rural Development.

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