What a Little Dew Can Do

Here's a bit of serendipity. Shadows play upon the grounds of Princeton Battlefield, charmed with dew on a Saturday morning.

Ever the resident tourist, a shadow selfie with Mercer Oak II. Had no luck getting the shadow to smile.

Sorry, but you can't look at any screen--TV or computer--without at least one obligatory car commercial popping up. The sound track runs something like, "If George Washington were alive today, ...", though he might eschew fossil fuel altogether and stick with a horse. Those founding fathers thought about long term consequence. What ever happened to that kind of thinking?

The original motivation for stopping during a drive by of the Battlefield was documentation, not aesthetics: to photograph the invasive porcelainberry overgrowing flowering dogwoods planted as part of the nation's bicentennial celebrations in 1976.

One of my recurrent cause celebres is to save the Dogwood Garden Club's dogwood legacy from the aggressive vine growth. From the green/yellow of the porcelainberry vines crawling over the red leaves of the dogwoods, you can see who won this year's skirmish. The Dogwood Garden Club doesn't know who I am, and for all I know they've forgotten that they ever planted these trees along the field's edge in the first place.

There was also an obligatory photo of the great disappearing bamboo patch. Two years ago, this was a thick clone of bamboo growing out over the path down to the Quaker Meeting House, but a series of well-timed cuttings with magic loppers over the past couple years have sapped vigor from the bamboo's giant root system. The decisive strategic intervention came this past June, when Kip Cherry and I cut down the regrowth from a cutting in the spring. It was some inconvenient toil, but deprived of any payback from that big investment in regrowth--two years in a row--the bamboo has nearly given up. A visit next spring should be light work, followed by a refreshing beverage on the Clark House porch.

Dew was also working some magic on the vista on Quaker Road near the towpath. Scattered pin oaks in a field of goldenrods.

Thanks goes to my daughter Anna for getting me out that way early on a Saturday, to drop her off for a busride to Philadelphia to do some canvassing. Otherwise, that encounter with morning dew would have never happened. Finally, a reason to be thankful for this election season.

Conquering Backyard Ivy in an Ivy League Town

After weeks of inaction, paralyzed by inertia and wondering if once again the garden would bowl me over with its growing power, I finally ventured out with gloves, dirt-friendly clothing, and some clippers to take on some of the backyard's longstanding "issues". To my surprise, there was satisfying progress to be made, that actually built on progress past.

Many gardeners have "border issues", that is, plants invading their yards from their neighbors', or vice versa. A friend recently showed me how lesser celandine was continually spreading into his yard from his uphill neighbor, and there are many stories of bamboo's indifference to society's artificial boundaries.

For years, my yard had waves of english ivy coming in from three sides, but two of my neighbors, without my saying a word, got rid of all of theirs. And where my yard abuts the park in back, I was able to get rid of the parkside ivy by taking the liberty of mowing it, after which the parks crews apparently have been weedwhipping any resprouts.

Taking advantage of the soft soil after yesterday's rain, I finally took on the legacy of ivy on my side of the fence, using physical means. The first phase was an on-hands-and-knees approach, pulling and cutting off any ivy growing on the fence.

Ivy heading up a tree got cut at the bottom. No need to pull it down. Cutting at the base is enough, though some people find it more satisfying to pull it all off.

For phase two, large pieces of cardboard were placed along the fence, overlapping, and any ivy still exposed further in was pulled out and thrown on top of the cardboard, where it will dry out. Some native vines--virginia creeper, wild grape, and poison ivy--were pulled as well, though the main goal was to eliminate english ivy. Gloves, long sleeves, and periodic washing of any potentially exposed skin with water should be enough to avoid poison ivy's effects, but we'll see.

The chickens came over to inspect my work, and seemed satisfied. Phase three would be to cover up the cardboard with chips or some other organic material that will hide the cardboard and keep it from getting blown by the wind. But the cardboard will quickly disappear behind a screen of growth in the yard, and some exposed cardboard may prove instructive to park users, who may decide to try using cardboard to deal with their own border issues.

Elsewhere in the yard was additional proof of how even intimidating weeds can be controlled by timely intervention. Only a few garlic mustards came up this year, because they've been getting pulled each spring before they go to seed.

And the big bamboo patch that once was advancing across the fence on the north side is down to a few weak sprouts easily cut. Other weeds--the Canada thistle and the dandelions--got the undercut treatment with a shovel.

There is, of course, the option of eating the young leaves of garlic mustard, and I saw a chinese woman inspecting some bamboo clones across the street, in search of bamboo shoots.

Some of the more aggressive native species got a rebalancing. A native floodplain species of goldenrod that spreads via underground rhizomes got pulled out in places. In the photo is the base of a bottlebrush buckeye--a beautiful native shrub that can start grabbing territory once established. It was a relief to discover that its expansionist ambitions are realized via above ground stolons that can be easily cut.

Mixed with the pulling and digging and rebalancing was some appreciating, of the subtle pendulant blooms of a Bladdernut, a native shrub found in only a few isolated spots in Princeton.

Can-Do Bamboo Control

A photo of the offspring of the Mercer Oak at the Princeton Battlefield would be appropriate for Memorial Day, but lacking that, a post on bamboo will have to do. My understanding is that the Revolutionary War was a war of attrition. The Continental army won few battles, but managed to sap the will of the British over the course of eight years.

You may never completely win the battle against bamboo, but conducting a war of attrition can turn an advancing monster into a minor nuisance. The goal is to starve the massive root system of energy, in other words, to lay siege. Cutting down all the stems immediately shuts down any solar energy collection, forcing the root system to use its reserves to sustain normal metabolism.

The roots then commit additional energy reserves to sending up new shoots. These can reach six or more feet before they start sprouting leaves. As these bare stems grow, be patient. Keep those loppers at the ready, then cut the long, still-soft stems down just as those solar collecting leaves begin to appear. Proper timing will cheat the roots of any return on a substantial investment in new infrastructure. As the roots weaken, each new set of sprouts will be smaller than the last.

For battles waged on the property line, an alliance with the neighbor will be critical.

Invasive Mile-a-Minute Spreading at Princeton Battlefield

Ever find yourself caring deeply about something the rest of the world ignores? We all pick our battles, and here's a really good one for the Friends of Princeton Battlefield and/or our governing institutions to pick.

Princeton has been graced in many ways of which it is not even aware, and one of those is the up-to-now absence of Mile-a-Minute, a thorny annual vine that grows up and over everything if allowed. Gardeners beware. This one's particularly nasty, and though it has gained a foothold in nearby areas, I've encountered it in only two locations in Princeton. One location is the Princeton Battlefield. The other is on the gravel road in to Rogers Refuge. Each year I pull it out, but by the time I remember to do it, a few of the vines' little blue berries have matured, so the infestation has been growing.

Obviously, my efforts are not enough. The town of Princeton has fortunately hired the NJ Invasive Species Strike Team in recent years to treat invasions by new species, but the Battlefield is state owned, and because of a lack of intervention it is now serving as a seed source that will affect all Princetonians, and not only for Mile-a-Minute.

Another issue at the Princeton Battlefield is the massive invasion by porcelainberry--a vine that rivals kudzu in its capacity to sprawl over anything and everything. Its overwhelming presence may seem to dwarf the problem with Mile-a-Minute, yet it can also be seen as proof that we really need to catch these invasions early, before they get out of control. Porcelainberry is not only at the Battlefield, but is also dominating large areas all along the Stonybrook in Princeton.

Here are the copious berries produced by porcelainberry vines as they smother the flowering dogwoods planted in 1976 for the nation's bicentennial. The berries turn pretty colors--blue, purple, pink, or white--thus the name, and the original appeal of the plant. But the plant has escaped the usual checks and balances that otherwise sustain balance in nature.

Birds eat the berries of porcelainberry and Mile-a-Minute, thus the concern that what's allowed to grow at the Battlefield will impact the rest of Princeton.

The Friends of the Battlefield group, by the way, has been doing a great job knocking out big stands of bamboo around the Clark House during its annual workday in April. Look in the distance in the photo and you'll see an open field, with only a small remnant of bamboo back near the woods.

But bamboo doesn't spread by seed, and so poses no threat beyond the Battlefield's borders. Volunteer sessions can slow down porcelainberry and Mile-a-Minute a bit, but for any lasting benefit, we need to get some professional intervention. Maybe the Friends of the Battlefield could apply for a grant.

In the meantime, be on the lookout for its distinctive triangular leaf, put on some gloves, and pull it out.

The Grass That Ate The King's Highway

There's a curious sight as you approach Montgomery from Princeton on Route 206. Something is eating the Kings Highway. 

That something is Phragmitis, most frequently encountered in its highly aggressive, non-indigenous form. In wetlands, it displaces even the tough native cattails. On the other side of town, in Rogers Refuge just below the Institute Woods, we've been working for years to keep it from taking over the marsh.

Spreading its tall tassels along freeway ditches, it dominates the New Jersey meadowlands and can be considered a worldwide weed. Its scientific name is as sprawling as its growth habit: Phragmites australis subsp. australis. The native version, less aggressive and now hard to find, is termed subspecies americanus.

One source describes the introduced variety as "a hardy species that can survive and proliferate in a wide range of environmental conditions." Sometimes it's planted intentionally, to treat wastewater or reduce soil erosion. Mostly, it plants itself, then expands relentlessly, oblivious even to normally intimidating barriers, like asphalt.

The common reed is a grass, like bamboo is a grass. Unlike bamboo, which lives for decades without flowering, Phragmitis blooms each year, combining abundant seed production with bamboo's powerful capacity to spread underground. That combination makes it a transformative force not only in nature but in human habitats as well. 

Taming Bamboo and Forcing Forsythia

While visiting Merida on the Yucatan peninsula in Mexico, we stayed at a hotel with rooms so tastefully decorated that one could turn in any direction and see a composed scene.

One object that put to good and decorative use what in Princeton is often an overly aggressive plant was this wrapping of dried bamboo cuttings into a vaselike pattern.

The same effect can be rendered with cuttings of forsythia, which have the added benefit this time of year of opening their flower blossoms after a week indoors.

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!"

The Second Forest of Institute Woods

In the Institute Woods, towards the end of the day, towards the end of autumn, it's not just the trees that cast long shadows. In the understory, a shadow forest grows, composed mostly of nonnative shrubs--winged euonymus, linden viburnum, asian photinia, shrub honeysuckle, multiflora rose and privet. Having evolved on a different continent in a different climate, they hold their leaves long after most of the native woodies have dropped theirs. Dominating the understory, these shrubs and vines constitute a second forest that serves up a second autumn, shedding their conformist green to show late-season reds and golds. 

There are second forests all around Princeton and beyond. The light green close to the ground in this photo is honeysuckle shrubs along Terhune Rd.

Here, viewed from the Streicker Bridge over Washington Road a week or two ago, are Norway Maples pushing up into the canopy of mature native oaks, beech, and blackgum, some of which are two centuries old. 

Bamboo at the Princeton Battlefield, bordering the Institute lands, offers another variation on the theme.

The different colors of the second forest provide a convenient code for easy long-distance identification. The pink here, down near the Friends Meeting House entrance to Institute Woods, means you're looking at winged euonymus. If it were growing in full sun, the color would be a vivid red, from which comes its other common name, burning bush. 

Here the pink of the winged euonymus mingles with the still green multiflora rose. 

Linden viburnum has its own distinctive fall color, 

as does Asian photinia, whose leaves tend to be broader towards the tips. It's usually more golden than this photo shows, and in Mountain Lakes and along Princeton Pike has turned whole woodlands golden this time of year. 

Mingling with the photinia here is the viny ever-green Japanese honeysuckle. 

Wineberry, with its fuzzy purple stem, is another Asian species with lingering green in late fall. 

Privet holds onto its green as well, here growing up around the tan stem of a shrub honeysuckle. 

Add global warming, which is bringing unusually warm and comfortable autumn days, and the feeling of gratitude for unseasonal warmth and color begins to  mix with a foreboding about the ecological consequences. Awareness creates an emotional undertow pulling against the uplifting effect of weather and color. The second forest flourishes in part because it is inedible to wildlife, which prefer and depend upon native species for food. The colors that greet our eyes this time of year signal a diminishing edibility for the forest's inhabitants. 

Four plaques tell the story of how the Institute Lands were saved from development in 1997, a half century after they were acquired. Though a couple key elements are left out--the Lenape Indians and Oswald Veblen--it is an extraordinary story, listing the major donors, 

the Taplins who led the way,

the coordination of governmental, institutional, and nonprofit entities that in NJ has been so effective in saving land. 

You can click on each photo to hopefully make it large enough to read.

Here, on this plaque, would have been a good place to mention the Lenape Indians as early occupants and stewards. A whole additional plaque could be dedicated to telling of Oswald Veblen's role as primary instigator of acquisition. As partially told on the IAS website, and more fully told by George Dyson in a talk at DR Greenway, Veblen convinced the early Institute leadership to acquire the land, then did the legwork necessary to bring all the parcels together. Over ten years, beginning in 1936, Veblen laid the foundation for open space in Princeton, with the acquisition not only of the Institute lands but also the 100 acres on the east side of Princeton that he and his wife Elizabeth later donated as Princeton's and Mercer County's first nature preserve, Herrontown Woods.

It's interesting to look at the chronology of open space initiatives in the Princeton area. The Institute lands were acquired between 1936 and 1945. In 1949, the Stonybrook Millstone Watershed Association was formed. Around 1959 Herrontown Woods was officially opened. In 1969, the Friends of Princeton Open Space came into being. In 1989, the DR Greenway was formed. Whether there's meaning in the 20 year increments of their foundings, all three nonprofits played a role in purchasing from the IAS the conservation easement that now protects the Institute lands from development.

Preservation tends to be celebrated more than management, so it's good to see there's a plaque celebrating maintenance, at least of the trails. The leadership and persistence needed to keep the woods accessible was first provided by Veblen, then later by mathematician Paul Dirac, then still later by what appears to be lasting funding in 2008 provided by Addie and Harold Broitman.  

Though the land is preserved, and the trails continue to be kept clear, and the richness of the Institute Woods has been researched and documented by Henry Horn and others, there is still a missing element for insuring the Institute Woods' longterm health. It's not clear that the woods hold the same biological richness seen in Veblen's time, or even Henry Horn's. With habitat restoration and deer management, we might lose the colors of the second forest, but gain a second preservation, this time saving the flora and fauna not from developers but from ecological imbalance and attrition of native species over time. 

The first preservation, in 1997, prevented intentional alteration of the woods by developers. But the woods is still being altered indirectly, unintentionally, through the invasion of introduced species and the banishing of predators that once kept deer numbers in check. The second preservation takes responsibility for the unintentional changes humanity has unleashed, and requires us to be active and informed participants in the forest's ecology. Clearing the invasive species that crowd the forest, and reducing the intense browsing pressure of deer, would begin to bring back the lovely vistas and sweeps of wildflowers that surely helped inspire the community investment in saving the land more than twenty years ago.