Wisteria's Tamed and Wild Twinings

The front porch of Morven has an educational feature for gardeners.

Go to the right side of the porch and witness Chinese wisteria twining up and to the right. 

Go to the left end of the porch and witness Japanese wisteria twining up and to the left. 

This contrast in twining direction appears to be a thing. There's agreement that the two species twine in opposite directions, but disagreement on how to describe it. The Japanese wisteria's winding up and to the left is described as either clockwise or counter-clockwise, depending on the website. The two websites I happened upon agree, however, that the direction of twining is not determined by whether the plant evolved in the northern or southern hemisphere. This is disappointing, as I had hoped for a pattern, which would be all the more satisfying if it happened to match the direction of swirl when water goes down a drain. Alas, some other force must be at work.

What Morven's porch won't show you is just how aggressive wisteria's twinings can become after a garden is abandoned. To comprehend the scale of expansion, you would need to travel to Herrontown Woods, where the extent of a wisteria clone (Japanese by the look of its twining) is still apparent in the woods. There are two clones, both covering more than an acre each. At their exuberant zenith, they had grown up and over trees and rendered the ground a monoculture of their foliage. One clone, up at Veblen House, is now mostly vanquished, in large part due to the extraordinary persistence in years past by Kurt and Sally Tazelaar. The success of that work depends, however, on ongoing vigilance to cut any sprouts still rising from the remnants of its sprawling root system. 

We are still very much in battle with the other clone, however, across the stream from the Barden. Each year for about four years now, the town has paid contractors to spend a couple days each summer applying systemic herbicide to this or that side of the monster. The herbicide is absorbed and translocated down, to weaken the wisteria's massive network of roots and runners. I think of it as comparable to the medicines we use to maintain our own health, well targeted and no more than necessary. 

Then, this past fall, a volunteer named Bill Jemas (posing in the photo with a wisteria vine) contacted the Friends of Herrontown Woods, looking for a good project to give him the equivalent of a workout in the gym. He came several times a week for much of the fall, working largely on his own, checking in with me periodically with a question or two. Cut, cut, snip, snip--he took on the still very intimidating tangle with hand tools and perseverance, making the hillside navigable once again, dotted with piles he made of the cuttings. He then announced his family was headed to Florida for the winter. Reportedly returning this spring, his contribution to the battle has already given us hope that the wisteria monster will not eat the Barden, towards which it was headed, and can be subdued like the one at Veblen House, so that we need only snuff out a few stray sprouts each year. 

A couple related posts:

Another Perilous Embrace--Wisteria and Horse Chestnut : About the horse chestnuts near Morven, and the horse chestnut that was getting overrun by wisteria in front of the 1755 house at 145 Ewing Street. Why does one often find a horse chestnut growing near a historic house? Because they bloom around Memorial Day?

Trees and Thunderbolts : The puzzling story on the Morven grounds of how a thunderbolt killed not the tree it hit, but the tree next to it.

Wisteria Contained

As a land manager, having fought back many a runaway acre of wisteria in a woods, tangled with and been tripped up by its myriad tanglings, even walked upon the tranpoline-like, crazy quilt its runners can weave above the ground, I can still feel amazement when witnessing a wisteria molded by intention--first at its abundant flowering, and second, that someone has managed to keep its wanderlust in check. 

This house is a couple doors up from Hamilton Ave. on Linden Lane. Similar displays are likely in progress on the front porch of Morven and at Marquand Arboretum. They hearken back to an era when people had the time and interest to tend to their gardens, when gardening was a relationship, and gardens had personalities. My parents had such a garden in Ann Arbor, MI, where I would trim the wisteria growing up their patio trellis. The flowers were pretty, but never reached the magnificence of this display on Linden Lane.

The wisteria in this photo is thankfully in the front yard, along a town street. If the owner ever lost interest in carefully maintaining it, there's no nature preserve nearby for the wisteria to swallow, only the house and the neighbors' yards. Having witnessed and reckoned with the unintended consequences of inattention, I can see both the beauty and the Burmese python-like potential lurking within, its expansionist nature for now contained.

Related posts:

Where Vines Tackle Trees: A wisteria that grew so thick you could walk on its web of runners without touching the ground. 

Another Perilous Embrace--Wisteria and Horse Chestnut: When wisteria gets loose in a neighbor's yard.

The Pleasure and Aesthetics of Native Seed Collection

One of the more pleasurable and aesthetic outdoor experiences in the fall is gathering seeds. I claim no expertise, but adhere to one simple rule: let the stem below the seeds turn brown before harvesting. And harvest when the seeds are dry. Also, be messy. Let some of the seeds fall where they would have fallen if you hadn't come along to take some. Alright, that's three rules. But that last rule is especially enjoyable. How many times in your life have you been told to be messy? 

There are more official rules out there for seed collection, particularly of uncommon species, but nearly all the seeds I collect now are either from my backyard or the Botanical Art Garden, both of which I planted. It's gratifying to see these new populations of local genotypes thriving, and to expand their local presence further. 

The plants I harvest from tend to be generous towards a human tendency to procrastinate. Many species hold on to their seeds for months in the fall and into the winter. But the prettiest time to be picking them is sooner rather than later, as they become increasingly weathered and threadbare as winter progresses.

Harvest of wild senna, seen in the first photo at a lovely stage when the leaves contrast with the dark seed pods, can be postponed considerably, as the pods hold onto the seeds for months.

The bright, fluffy clusters of ironweed seeds are easy to identify on stems that can reach 8 feet.

Rose mallow hibiscus (Hibiscus moscheutos) holds its seeds in convenient cups. Best not to wait too long, because there's a slow attrition to spillage and insects as winter sets in.

As with other sedges, the seed clusters of morning star sedge (Carex grayi) will break apart as fall progresses. Some other local sedges with easily collectible seeds are squarrose sedge and fringed sedge.

The seeds of bottlebrush grass, attractively arranged along the stem, were already starting to fall off when I collected them in late October. Just grab the dried stem between thumb and finger and pull upward to strip the seeds. This is an attractive understory grass. 

The seeds of turtlehead (lower left in the photo) are still ripening, having shown their own form of procrastination, waiting until early fall to bloom.  

Collecting seed has extra meaning and purpose this fall, because many of them will be planted along a wooded slope in Herrontown Woods where a large clone of wisteria had pulled down some of the trees, creating openings where sun can reach the ground. Years of effort, particularly with the consistent, transformative work over the past year or two by volunteer Bill Jemas, has largely snuffed out the daunting wisteria clone that had taken over an acre or two, choking other growth as it steadily expanded along this broad hillside. It even somehow traversed the creek and was headed towards the Botanical Art Garden, adding another layer of urgency to knocking it out. Into the void created by our wisteria removal has come garlic mustard and stiltgrass, but this year we pulled those before they went to seed. 

With much of the slope now bare (the photo shows wisteria to the right, cleared areas to the left), it's time to introduce native plants. We could toss the seeds hither and yon, but I like to give them a better chance by being more deliberate. Deer are an issue, of course, given their appetite for native plants, and my plan is to plant seeds in small circles here and there, creating loci a couple feet wide. I like to scrape a thin layer of dirt away, scatter some seeds, then sprinkle some dirt on top and tamp it down. Then I'll place a 3 foot high plant cage around each circle. Those that grow inside the cage should be protected enough to mature and produce seed that can then scatter beyond the cage on its own in subsequent years. 

It's actually a good way to find out which species the deer leave alone, and which they munch on. We are, in a way, creating "deer feeders" by protecting a few plants inside the cages--plants that each year spread beyond the cages, where the deer can eat them. This approach has been successful at the Barden. Thanks to the town's investment in annual deer culling, many of the plants that sprout beyond the cage survive. 

Of course, all of this thus far is talk. Procrastination is a particularly powerful factor when it comes to getting plants or seeds in the ground. There's so much other work to be done! What's real and lovely, and has actually happened, is the seed collecting. 

Where Vines Tackle Trees

Perhaps we'd suffer cold more gladly if occasionally reminded of how a warmer climate can power unwanted invasions. Our cold NJ winter may, for instance, be knocking back the pine bark beetles that have been moving north into the Pinelands as the climate warms. And we can be thankful that Asian wisteria is not as aggressive here as it is further south. There's a place I used to live, in Durham, North Carolina, where the wisteria grows so densely you needn't touch the ground when you walk. The lateral shoots make a web on the ground,

while the vines reach up and rob the trees of sunlight.

Whole trees collapse, weakened by the weight and lack of sun. The wisteria, which probably started as one small plant brought home from the nursery long ago by a neighbor, has over the intervening decades invaded several acres of woodland that the homes back onto.

Now a 17 acre nature preserve, the woodland displays an exaggerated version of the classic eastern woodland profile--native trees with a mostly exotic understory. Most of the non-native invasives can also be found in NJ, but behave less aggressively because of the cooler climate. Here's a very robust climbing Euonymus, whose hairy stem rivals that of poison ivy.

This tree's branches are actually the lateral shoots of the Euonymus vine.

Elsewhere in the preserve are extensive swaths of Vinca major, English ivy, bamboo and privet, growing so densely that native understory species have little chance of surviving. The preserve was free of Japanese stiltgrass until its seeds hitchhiked in on the tire treads of vehicles brought in to do emergency repair on a sewer.

My friend Perry has been leading workdays to remove the thick stands of privet in this floodplain woods. On the left is before, on the right is after. Invasives removal creates pleasing vistas, safer trails, and sometimes leads to the discovery of a few solitary native shrubs that have been hanging on despite all the competition, such as hazelnut and blackhaw Viburnum.

Another Perilous Embrace--Wisteria and Horse Chestnut

It's almost like someone chose to plant horse chestnuts in front of Princeton's Monument Hall knowing that their blooms would coincide with Memorial Day ceremonies. Here, while taps is being played, one of the first African American marines, Wallace C. Holland, Jr, salutes, and fellow veteran and guest speaker Elana Duffy (under the bell of the horn) looks on.

Meanwhile, elsewhere in Princeton, in front of a home where Thomas Jefferson reportedly stayed when Princeton was briefly the nation's capital, another horse chestnut has less in the way of freedom to celebrate. The blue flowers are of a wisteria vine that's been steadily consolidating its claim to the tree's infrastructure.

From a distance, the scene looks like this, with the wisteria each year adding weight while reducing the tree's access to solar energy to maintain its strength. The effect is pretty, but we'll see how long the tree can take it.

Unlike the American colonies, the tree has no way to free itself of oppression.

Coyote Spotted at Princeton Battlefield

 A coyote was spotted at Princeton Battlefield this past Friday, March 24. 

Thanks to David Padulo for sending around this photo of the beautiful animal. 

At the time, David (hopefully not the coyote), was on his way to Port Mercer "to check off a Mercer County Life bird (Tundra Swan)," and so happened to have his camera. Port Mercer, for those like me who would assume there aren't any ports near Princeton, turns out to be just a couple miles upstream: the historic settlement where Quaker Road crosses the canal. According to David, the tundra swan was off track, a half hour away from where they are more typically seen, at Assunpink in Monmouth.

As an avid birder, David has taken an interest in Princeton's birding mecca, Rogers Refuge, and now leads the Friends of Rogers Refuge. David, shown here carrying a wood duck nest to a more auspicious location, represents a new generation of stewardship at the Refuge, taking over from Lee and Melinda Varian, who have done so much to keep trails open and control invasive species. 

Turning 83 has not deterred Lee from wielding a chainsaw to maintain the refuge. After meeting with David to discuss how the refuge's marsh might hold more water (a lot of water drains out of the refuge where this photo was taken), Lee and I spent a highly productive hour cutting a clone of wisteria vines that has been growing up and over some trees. If left to grow and expand, the wisteria would eventually swallow the forest surrounding this remarkable marsh. The nonnative wisteria can expand without restraint because there isn't the equivalent of a coyote to keep it within bounds. 

Garlic Mustard Pulling Party--Sunday, 10am

Join us this Sunday, June 11 at 10am, before the day heats up, to pull garlic mustard before its seedpods have a chance to burst. We'll have some refreshments on hand, the better to socialize while snipping off the seedpods. Veblen House is up the gravel driveway across the street from 443 Herrontown Rd, or walk up from the main Herrontown Woods parking lot off of Snowden (map here).

We should be able to get all the remaining garlic mustards--half having been pulled last week by volunteers. Garlic mustard is a biennial, meaning it bears seeds the second year and then dies. If we bag up all the seeds each year, the population will fade away, which is good news for native wildflowers we want to reestablish here next to Veblen House.

The first year, garlic mustard looks like this, gathering energy for the seedhead that it sends up the second year. The species was brought to America by European settlers wanting to have something green to eat in early spring, after the long winter. Unfortunately, the plant has very aggressively spread into nature preserves, crowding out native species. Even after several centuries, the wildlife still don't eat it enough to keep it in check.

Another invasive we'll cut back is wisteria. We have almost vanquished an acre-sized, kudzu-like clone of wisteria that just last year was smothering much of the garden and weakening trees. This year's mild followup is really important to starve the roots of any chance to rebound.

Bring hand-pruners and loppers, if you have them, gloves and work shoes. We'll also provide some tools.

Here's a weed we'll allow to grow: moth mullein, a few of which have popped up in the horse run next to the house.

Other projects of the Friends of Herrontown Woods (FOHW) to promote sustainable landscaping include caring for a detention basin at nearby Smoyer Park. The basin was converted from turfgrass to native grasses and wildflowers. FOHW is proactively removing highly aggressive weeds like Canada thistle and crown vetch before they can get established, and adding local native wildflowers like this Hibiscus moscheutos to increase diversity and color.

Whither Romance? Wisteria Meets Horse Chestnut

 It was just one of those things.
Just one of those crazy flings.

A trip to the moon on gossamer wings.
Just one of those things.

If they'd thought a bit about the end of it,
When they let the wisteria start climbin' round,
They'd have been aware that this love affair
Was too hot not

to fall down. (Stay tuned.)

--Lyrics mostly by Cole Porter

Fig Buttercup Alert--Little Flower, Big Problem

Yes, spring can be lovely, with some cheery displays of daffodils, and magnolia trees in their glory. But it's also an all too good time of year to witness with dismay and alarm the ongoing and accelerating invasion of the Princeton area by fig buttercup. Also known as lesser celandine, it's a small spring ephemeral that seduces with its pretty flower, then takes over your yard and garden.

It has already radically changed the spring landscape over in the Pettoranello Gardens and Mountain Avenue area, and I've watched it spreading from yard to yard over the past five years in my neighborhood near Hamilton Ave and Harrison Street.

These photos are from Maple Street just down from Nassau Street, where a still localized infestation is radiating out from one of the yards. A yard will have one or two plants the first year, dozens the next, quickly multiplying to hundreds and thousands. It's pretty easy to see whose yard was first by the density and extent of the invasion.

Across the street, the fig buttercup is taking over the lawn and flower beds.

The next door neighbor has an invasion in its earlier stages.

Why be concerned? There are many degrees and styles of invasiveness. I'll compare fig buttercup with other aggressive plants below, but here are the essentials: Fig buttercup is an introduced species that has escaped any limiting factors that may have been present where it evolved. It's poisonous, so nothing eats it. The seeds and the abundant underground tubers allow it to spread rapidly. It can grow in the sun or shade, garden or nature preserve.

Some gardeners may feel relief that, like other spring ephemerals, it will fade back into the ground after a couple months. But that seems small consolation as it increasingly displaces other plants that might otherwise grow.

By comparison, myrtle is a groundcover that people plant and may later regret as it takes over flower beds. But it doesn't spread down the street to ultimately pave the local watershed. It merely vexes the gardener who planted it.

By the same token, wisteria vine poses a much smaller threat than porcelainberry. Though an abandoned wisteria vine can spread over an acre or more, weakening trees and suppressing all other growth, it doesn't spread by seed, so remains localized. Porcelainberry is a vine that not only smothers all other vegetation, including trees, but also spreads to new locales by seed.

Most pesky weeds of the lawn--wild garlic, dandelion, false strawberry, ground ivy, etc--have not become problems in nature preserves because they are either edible to wildlife or intolerant of shade.

That's what makes invasives like fig buttercup and stiltgrass stand out as major threats. They spread rapidly, tolerate shade and a variety of soils, and nothing eats them. Since fig buttercup dominates in spring, and stiltgrass dominates in summer and fall, they represent a one-two punch that dominates the landscape visually, and leaves little chance for other herbaceous species to prosper. Since both are not eaten, yards and preserves become increasingly inedible for wildlife.

Fig buttercup can be confused with winter aconite, which also blooms early with a similar flower, but the leaves are much different. Though nonnative, I've never seen winter aconite spread beyond the limits of a yard.

This photo shows the native marsh marigold in the foreground, with leaves much larger than fig buttercup's, which is in the background. (For a closeup comparison of the two species, click on this link.) The marsh marigold, by the way, is very rare. I've seen it only a couple times in the wild. I planted the one in the photo, over at Pettoranello Gardens, purchased from Pinelands Nursery many years ago.

Click here for past posts about fig buttercup (lesser celandine), including a letter I wrote to the Town Topics two years ago that struck a nerve.

What to do? If there are just a few plants, you can dig them up and put them in the trash (not the compost), being careful not to leave any small underground tubers behind. But though I've had organic sympathies all my life, and don't like to use herbicides, the easiest way is to use a squirt of 2% glyphosate on the leaves (Roundup is the most common brand, but more generic forms are available), or else some herbicide more specific to broadleaf plants. We take medicines, and when used responsibly in a targeted manner, herbicide can play a similar role in nature.

Environmentalism has been too caught up in good vs. bad, when the biggest threat to nature and ultimately ourselves, whether it be carbon dioxide or a pretty little flower, is too much of a good thing.

Last Chance to Pull Stiltgrass

This week and maybe next are your last chance this year to pull stiltgrass (Microstegium vimineum). This mega-invasive is an annual, so the logic of countering its spread is to pull it before it can produce and drop seed. If the seeds haven't loosened yet at the end of the stalk, you can still pull it. Throw it in the trash, or if there's a lot, make a big pile of it so that any seeds that sprout the next year will all be in one place and easily covered or pulled. Definitely don't put it in your compost if its seeds are forming. If stiltgrass is just starting to invade your yard, pulling as completely as possible now will greatly limit its seedbank for next spring. Another strategy for large stands is to let the stiltgrass grow, then just as it begins to flower mow it short and hope its feeble roots don't have enough energy to grow another flowering stalk. 

For those fuzzy on identification, google lots of images, and look for the silver line running down the middle of the leaf. Stiltgrass can grow in the shade or sun, climb up to four feet, or thrive in a miniature state while ducking below your mower in the lawn. It's incredible survival skills include being incredibly inedible for wildlife. Stiltgrass gives nothing back to the habitats it increasingly dominates.

More on Stiltgrass, and a Success Story

Walking in the local woods, you've probably seen this kind of scene--what looks like a grassy meadow extending through the forest. In the filtered light of the understory, its simplicity and lushness may have some visual appeal. And yet, in some ways what you are looking at is the ecological equivalent of an urban food desert. 

Stiltgrass is an introduced plant that could be called a pervasive invasive, able to thrive most anywhere and dominate whole landscapes. Its success has come in part through being inedible. As wildlife selectively eat native vegetation, the stiltgrass expands, preventing the native plants from rebounding.

Unlike another nonnative annual weed that can look similar, crabgrass, stiltgrass becomes ubiquitous because it can thrive in sun or shade. That means the stiltgrass invading your lawn and flower beds can continue spreading ad nauseum into the nearby forest, or vice versa.

We used to call it bamboo grass--something in the shape of the leaves is reminiscent. The stiltgrass name refers to its angular growth, with each segment supporting the next as it climbs up and over fallen logs and other plants. Packing grass is another common name, referring to how it was once used to pack porcelain for shipment. That's probably how it first reached the U.S., in packing crates sent to Tennessee. 

When I first encountered it, growing on the bank of Ellerbe Creek in Durham, NC, I thought it graceful. Then came Hurricane Fran, bringing floods and fallen trees. In the aftermath of that massive disturbance, stiltgrass exploded in the landscape, expanding and ultimately choking forests with its vast, dense stands. New Jersey proved no different. 

Stiltgrass tends to establish itself along roadsides. Here it is growing in a green ribbon along Herrontown Road. Trails, too, provide an avenue for extending its reach, its tiny seeds carried on boots or the hooves of deer.

Though stiltgrass has covered large areas of woodland in the eastern U.S., we have found it worthwhile and even satisfying to counter its relentless incursions. Today in the Barden at Herrontown Woods, some volunteers pulled it out of a patch of native jewelweed along the edge of the parking lot. 

Nearby, on land where we have largely eliminated a massive clone of wisteria, stiltgrass was starting to move into the void. If nothing were done, this open woodland would have become a pasture of stiltgrass. But we have acted early enough to be able to remove all of this year's stiltgrass, dramatically reducing the seeds available for next year's crop. This photo shows the last patch before we pulled it. 

Interestingly, there are native grasses that look a little like stiltgrass, the main one being Virginia cutgrass (white grass), Leersia virginica. It has longer, narrower leaves that lack the silver stripe down the middle. As is a common ecological refrain, the native grasses "play well with others," not forming stiltgrass's massive, exclusionary stands. Some smartweeds like Lady's Thumb can also bear a resemblance. 

Herrontown Wood Revisited

It was a walk through the ages, as thirty people came on the first Friends of Herrontown Woods nature walk last weekend, to see the Veblen House and farmstead, and the newly restored trails through the 142 acre tree-and-boulder garden. There were kids, adults, and a cockapoo named Wynston, whose name was claimed to be the only one that rhymes with Princeton.

The walk began with the sound of a pileated woodpecker off in the distance, and there was a rare opportunity to see Kurt Tazelaar sitting down. Kurt--a force of nature, in nature--and Sally (with camera on right), had cleared this trail, which took us past evidence of past quarrying,

and the intimate embrace of trees and rock, as with this white oak. Some time ago, we counted the rings of another white oak that had finally succumbed to a windstorm in this mature section of forest above the cottage, and found it to be at least 150 years old. The trees and the boulders co-led this nature walk, speaking so eloquently of time and endurance.

The boulders got bigger as we climbed the slope of the ridge. Many of the boulders have natural fissures, some of which were broken apart back in the quarrying days. If you look closely, you can see a series of drill holes along the edges,

which Kurt had pointed out earlier. Peter Thompson later sent us a link explaining the stone splitting technique used back in the day.

In some places, the land is pockmarked, as if boulders had been extracted from the landscape like molars, leaving a broad hole in the ground.

How the broken off pieces were transported, and to what use they were put, is part of the unfolding story as Herrontown Woods undergoes a restoration that in some ways is like the restoring of a painting, at once timeless and dynamic. Time will tell if the past's story will be told.

Perhaps some of the quarried stones ended up in this circular horse run--a bit of culture overrun by horticulture, in the form of wisteria likely planted long ago by Elizabeth Veblen.

A major cultural fixture in this wild setting is the Veblen House, which drew lots of interest and discussion about how it could be used for meeting space and nature education. (photo's from a few weeks ago)

The walk benefited from all the collective wisdom assembled. Many came who work to sustain other parks and preserves--Marquand Park, Gulick Preserve, TRI, Mercer Meadows. A couple who had been active with a Friends of Herrontown Woods group in the 1970s came, ready to help with this new wave of energy and interest. It felt good to have Princeton's original nature preserve back in the fold, its arteries cleared and flowing with appreciative humanity once again.