Mile-a-Minute Vine in Princeton

Each year I conduct a solo campaign to keep the highly invasive weed Mile-a-Minute out of Princeton. It's a prickly annual vine that grows each year from berries produced the year before. Knock it out before it produces berries, and eventually there will be no berries to sprout. Otherwise, the infestation will grow and birds will spread the berries across all of Princeton, to spring up in backyards and vex homeowners with its thorns and rampant growth.

I know of two infestations--one at the Princeton Battlefield, the other down off West Drive on the gravel road to Rogers Refuge. Yesterday, passing by Princeton Battlefield, I stopped to uproot what Mile-a-Minute I could find and leave it on the lawn to dry in the sun. Like most annual plants, it has whimpy roots and can easily be pulled, wearing a good pair of gloves.

Princeton Battlefield has a remarkable history, which makes it all the more remarkable how ahistoric the landscaping is. Non-native turf is surrounded by giant kudzu-like topiaries of non-native porcelainberry vine growing over the native dogwoods that were proudly planted for the 1976 bicentennial. There's little hint of what the Clark Farm looked like on that fateful day in January of 1777. The lack of botanical context doesn't fit with the people and era the Battlefield is meant to celebrate. Plants were important to George Washington and other leaders of his time. They were farmers. It's not coincidence that the United States Botanic Garden was built to stand next to the U.S. Capitol building. What grew upon the land mattered back then. They didn't mow the lawn and think their work done.

Seeing a landscape so invaded and out of balance, I sometimes imagine a hospital with no doctors or nurses, only custodians dedicated to keeping the place clean. The patients are on their own, unless a volunteer doctor happens by to treat some localized infection. That's the situation in the vast majority of our landscapes, cared for by custodians armed with raucous mowers and leaf blowers, oblivious to the complexities of nature and its needs. 

In the meantime, I pull the Mile-a-Minute, trim back some small portion of the porcelainberry vines so the dogwoods might live another year, and wonder at the world's disconnect with nature.

The two photos show 1) porcelainberry vines overwhelming a dogwood tree, and 2) another sea of porcelainberry in which only the similarly invasive Canada thistle can manage to lift its pink flowers above the swarm.

15 Flowering Dogwoods Rescued from Smothering Vines at Princeton Battlefield

Saving legacies is what Princeton Battlefield is all about, and one legacy we sought to save during a big workday organized by Kip Cherry were flowering dogwoods planted for the nation's bicentennial in 1976. I do most of my habitat restoration work at Herrontown Woods in eastern Princeton, but have been visiting Princeton Battlefield periodically to help tame bamboo monsters, care for native chestnuts and prevent vines from completely smothering the dogwoods. Having ten able and spirited volunteers at this year's Battlefield Society's Clean-up Day made real progress possible.

Kip Cherry (front left) began the afternoon with a moving description of the great battle that took place there in 1777.

Ten of us then headed across Mercer Street to liberate the flowering dogwood trees lining the edge of the field. The dogwood flower buds, poking through the drapery of vine growth, provided inspiration, with their promise of beauty in the spring, and nutritious berries for the birds in fall.

This was the curtain of vines we cleared away with loppers and pruning shears, while dodging poison ivy and the thorns of multiflora rose.

Here's a "before" shot, showing porcelainberry draped over three dogwood trees. (photo from last fall in a previous post)

And here's the "after" shot, taken from underneath the rescued dogwoods. We worked to create an open space between ground and lower limbs so the vines cannot easily climb back up.

Thanks to our brave and skillful crew, who came from near and far to liberate fifteen dogwoods over the course of three hours.

I liked this pose when the work was done. As always happens on workdays, there were good conversations to go along with the physical work. I gained some Veblen House-relevant information about Long Island and Connecticut, and heard some positive testimonials about electric cars like the Chevy Volt, which combines 60 mile battery range with a backup gas engine. One owner said she'd spent only $9 on gas since last summer, and hadn't noticed any rise in her electricity bill from charging up the car at home. While restoring some history, it was good to hear the future in the form of electric cars might be at hand as well. The same thinking goes into saving legacies, whether they be dogwood trees or the world's climate.

Senator Kip Bateman and Assemblyman Reed Gusciora dropped by to help out.

Here is Kip Cherry's summary of the day:

"Our Clean-up Day was a big success! The sun peaked out, and from all reports everyone had a great time, the Park looked a lot nicer when we were done, the CWT t-shirts were well received, and the Sierra Club came through. Senator Bateman and Assemblyman Gusciora both arrived and put their shoulders to the wheel. A large group of kindergartners picked up fallen sticks, while others removed invasive porcelainberry vines from dogwoods, cut down bamboo, and cleared encroachment along the pathway to the Quaker Meeting House. Special thanks to Kim Gallagher and Steve Hiltner for leading teams, and to Gary Nelson and Randy Riccardo for their hard work!"

Porcelainberry: the Vine that Ate Princeton

Here it's Friday of National Invasive Species Awareness Week, and nary a post about invasive species!

First, readers should be aware that there are contrarians out there, writing books, articles and opeds, trying to deny that invasive species are a big problem. It's fascinating to analyze their mental gymnastics and deceptions, which are similar to those used to deny the reality and danger of climate change. I've picked apart their faulty logic in posts that can be found at this link.

Now, on to our porcelainberry tour of Princeton. You won't find it in shady areas, where other invasives like stiltgrass, garlic mustard and winged euonymus thrive. Rather, porcelainberry threatens to smother all of those sunny openings and edges that shade-intolerant plants depend on for survival. Porcelainberry is related to our wild grape, but much more aggressive. Your first impression will be, "What lovely multicolored berries!"

Your second impression, as it climbs up the stems of your shrubs, like this elderberry, might be, "Oh, a little rambunctious, but those berries are so pretty!"

Your third impression, as it turns your yard or park into a monocultural topiary, will be more along the lines of, "OMG! HELP!" No, this is not kudzu growing along a freeway down south. This is porcelainberry winning a modern day Battle of Princeton, with stealth and persistence far beyond anything we distracted humans might muster.

This is what a nearby patch looks like in December, just down the road from the Princeton Battlefield, along Quaker Rd between Mercer and 206. Invasive vines and shrubs can seem less overwhelming in winter, which is actually a good time to remove them. In spring and summer, though, all that growth energy can be intimidating.

And this is what porcelainberry is doing to the sunnier portions of our lovely nature trail off the DR Canal Towpath near Harrison Street. The blackbirds may say hello to the berries, but it's bye bye to the diversity of native wildflowers underneath that foliar blanket.

Turns out porcelainberry's a soccer fan. Here it is in the cheap seats at Princeton University's Roberts Stadium, at one end of the field,

and at the other.

Here it is (light blue and pink berries) in that "second impression" stage, climbing over a honeysuckle shrub (red berries) at Quarry Park. Give it a few years and it may reach the "OMG" stage.

I haven't seen much of it in eastern Princeton yet, but we'd be smart to keep an eye out and remove it before the berries mature.

Otherwise, sunny edges everywhere will look like these hapless flowering dogwoods, planted at Princeton Battlefield in 1976 for the nation's bicentenial, and now struggling to survive beneath a spreading blanket of porcelainberry.

Note: You can help liberate the dogwoods from the porcelainberry and other vines on Saturday, April 1 at 1pm. I've been collaborating with the Princeton Battlefield Society on invasive species work for the past several years, and will be leading a group to preserve the dogwoods that line the field on the north side of Mercer Street.

Another group of volunteers will be continuing the multi-year effort to reduce the bamboo clones near the Clark House, which we're actually having considerable success without herbicide. 

For purposes of identification, here are a couple closeups of porcelainberry. The berries are distinctive, with different shades of blue, red and white.

The leaves are easily confused with wild grape. This photo shows how variable is the shape.

I hope everyone's having a happy National Invasive Species Awareness Week. We'll end with a short Q and A:

• Are all nonnative plants invasive? No. Nonnative refers to origin. Invasive refers to behavior.
• Why are invasive plants invasive? Oftentimes, it's because the native insects/deer, etc don't eat them, giving them a competitive advantage. To regain the balance we lost by introducing species that evolved elsewhere, people end up having to be the herbivores, wielding saws and loppers.
• One nice thing about invasives? They get us out in the woods for workdays.