Privet

This time of year, I am known by those who ride in the car with me to call out “Privet!  Privet!  Privet!” in the same tone that others might use to acknowledge rattlesnakes on a footpath or hippopotami in the swimming pool.  The only difference being that privet is far more common than the other monsters, so I sometimes have no chance to breathe between curses.  I have in fact on some occasions experienced rattlers politely and quietly slithering away.  I only wish I could say the same of Privet!

Privets are woody landscape plants of the genus Ligustrum, and they are native to parts of Africa, Asia, and Europe.  They have been favored for hedging material in Europe for centuries, most widely since the start of World War II in Britain when landowners were asked to cut down their iron fences so the metal could be used to make weapons.  Substitution required a fast-growing hedging material that grows vigorously in many conditions.  Ligustrum vulgare, common privet, and its cousin Ligustrum sinense, Chinese privet, to the rescue! 

Needless to say, any plant that was widely planted in Great Britain in the 1930’s and 1940’s became by definition a favored plant in the United States and the Antipodes, where horticulture and garden design followed Britain’s lead closely.  Here and there, privet had been planted in America by British colonizers, but it took off into the wild in the 1950’s.

Privet was no rescue plant for temperate gardens on this side of the Atlantic. 

At the close of 2025, it will no longer be legal to propagate, sell, or purchase privet in the state of Ohio.  For good reason.  Privet is one of the most invasive plants ever to have been introduced into the United States.  It is already being attacked by gardeners and governments throughout the nations of New Zealand and Australia.  It is a classic example of an invasive plant success story.

How, in particular, you may ask?  There are many mechanisms by which it outcompetes desirable native plants.

Privet leafs out some weeks ahead of most shrubbery native to the south, east, and midwestern USA.  Driving through Cuyahoga and Geauga counties at the end of March, we can all see a lovely fresh green understory, 3’ to 12’ tall, emerging in the woods beneath the still empty branches of our deciduous trees.  Along streams and riverbanks, rich margins of green shrubbery billow forth.  Upon inspection, literally all of this early greening turns out to be thickets of privet, and it is already shading any possible sites where native plants might otherwise have taken hold.

Of course, the privet has to have the opportunity to set seed into the wild spaces of our woodlands.  We can thank our birds for that.  The fruit of privet is a small black berry, about 5mm in length, containing a pair of seeds.  Here in Ohio the fruits are produced primarily in late summer and fall, although they may hold on the plant into the following spring.  When birds eat the berries, the seeds pass through birds’ guts, are scarified, and drop to the ground encased in a small “plop” of birdie fertilizer.  One mature plant can produce over ten million seeds each year.

Seeds may also be spread by running water.  The privet thickets that establish themselves along streambeds drop berries into the stream, which carries the berries to a point where they are caught along the streambank.  A seed sets.  Another privet plant grows.  Another ten million seeds are set annually.

Aha, you may ask, but where did the plants producing these berries come from in the first place?  From the human who chose to plant them, of course.  It is often quite easy to see that a major outcropping of privet bursts forth only a few yards away from an intentionally planted hedge. Humans are the offenders who began this privet invasion.

We have also planted privet unwittingly.  Ligustrum is a genus within the plant family Oleaceae, the olives.  So is the genus Syringa, the lilac.  For well over a century, the more delicate cultivars of lilac have been grafted onto hardier rootstock from a related plant, usually common privet.  If the lilac portion of the plant dies off above the graft, or if the rootstock sends out suckers, the intended lilac plant in fact reverts to privet.  Your great grandmother’s historic privet hedge might in fact have been planted 100 years ago as her prized lilac hedge.  Many “outbreaks” of privet near older homesteads began their lives as lilacs.  This method of lilac propagation is still recommended.  Please do not do it;  use an alternative means.

The roots of privet plants also range widely and shallowly from the main plant structure, and establish clonal colonies.  Thus roots of one single plant can spread underground, with new shoots rising from the rootstock and establishing what appears to be a second plant, then a third, then an entire stand, but in fact the new plants are merely clones  of the first.  Ad infinitum.

And, finally, there are the flowers arrangers.  In fall, many arrangers rely on homegrown fruiting branches for a framework of a seasonal arrangement.  Privet not only leafs out early in spring;  it also holds its foliage relatively late in fall.  So an unwitting arranger may clip a few branches of dark olive green, tidy foliage laden with shiny blue-black berries to set off dahlias and asters in an autumn display.  And then the arrangement is discarded into the compost heap or trash.  Another innocent human, spreading privet.

Speaking of innocence – if your garden does include privet, please take extra care of children and pets around the plant.  The berries are poisonous to people and dogs, and recent studies suggest eating privet berries and foliage can also sicken horses.  Some people may develop rashes or hives after rubbing the foliage.  Asthma attacks and respiratory allergies are also connected to blooms of privet pollen scattered by its highly scented June flowers.

Studies published in 2010 suggested that within 100 years privet would have become what is known as a “noxious weed” in the state of Ohio.. From that designation, planting and propagating it would be made illegal not many years later.  Yet it gained the noxious designation only ten years later, and will be illegal here in two more years.  This plant, and all of the nine species of it now introduced to the USA, is one of the worst enemies of our native plants, of our waterways, and of our ecosystems.  Please do not plant it.  Please do not treasure it.  Please remove its baby seedlings from your garden.  And if you have a privet hedge, like so very many homes in Ohio, please consider replacing it with a native plant that will support our ecosystem and our food chain.