Porcelain Berry--New Jersey's Kudzu

Anyone for a little topiary? This shot was taken last week at Princeton Battlefield, where the battle for Princeton's open space is currently being won by the kudzu of the north--porcelainberry. A vine native to northeast Asia, porcelainberry is related to grapes, and grows over ground, shrubs and trees like a grapevine on steriods.

It has beautiful berries, which may have helped gain it transport originally to our continent, but its rapid advances along the DR Canal, at the Princeton Battlefield, and elsewhere in recent years does not bode well for any other species seeking to share in the sun.

Lest one think all is lost, the Oct. 11 Princeton Packet includes a picture of volunteers at the battlefield removing another invasive weed--bamboo. The recent workday was a collaboration of the NJ Div. of Parks and the Sierra Club.

Hicans and Other Useful Trees at Princeton Battlefield

When people think of trees at the Battlefield, the first and perhaps only tree that comes to mind is the Mercer Oak, which these days is Mercer Oak II, an offspring of the original, donated by Louise Morse, a remarkable woman who spent much of her long life advocating for good causes. She was wife of Marston Morse, one of the first generation of mathematics faculty at the Institute for Advanced Study.

The Mercer Oak plays an ambassadorial role for the Battlefield, a star, positioned near the road while other less heralded trees serve more prosaic functions further back.

The young oak, a teenager or perhaps a young adult at this point, is flourishing after donating much of its foliage to the insect world two years ago.

It's appropriate that the oak came from Mrs. Morse, because she herself was extraordinarily long lived, reaching 105, and, like an oak that gives of its foliage to 100s of species of insects, gave generously of her time to such causes as Stuart School and civil rights.

Closer to the house are less known but more edible trees. Beneath this one is a bumper crop of pecans, but the tree is not fully a pecan tree.

It is, instead, a hican. Like a mythical beast whose body doesn't match the head, it has the base of a hickory and the top of a pecan. You can see the change in bark from rough to smooth about six feet up on the trunk.

Chinese chestnuts, too, are having a banner year.

In front of the house, a native chestnut we planted (15/16th American), is hanging in there, though its trunk is nearly girdled by the blight.

It, too, is laden with chestnuts.

Another native chestnut on the other side of Mercer Street had looked to be flourishing, but succumbed suddenly this year. The disease does not kill the root, however, so multiple sprouts rise from the base, to be browsed on by deer.

Undeterred, Bill Sachs and I added protection to some more recently planted native chestnuts that were getting beat up by the mowers. Such a perilous world these trees enter into.

Along the field edge, the bicentennial dogwoods planted in 1976 are benefitting from the work volunteers did this spring to keep the porcelainberry vines off of them.

This shot from underneath the trees shows the wave of porcelainberry that wasn't quite able to reach the lower branches of the dogwoods.

The less shading from the vines, the more berries the dogwoods can produce to fuel the fall bird migration.

This would be the fate of the dogwoods if we didn't help them out--completely enveloped by the porcelainberry.

Two of the classic inedible trees to be found around historic homes are horsechestnuts and black locust. Clark House lacks the horsechestnut but has several grand black locusts. Black locusts provided extraordinarily rot-resistant wood for fenceposts, abundant flowers for honey, and some say they help steer lightning strikes away from the house.

Quiet Botanical Battles Staged at Princeton Battlefield

July 19, and it's a quiet scene at the Princeton Battlefield on a weekday afternoon. The Mercer Oak is looking robust in its corral of sacred ground. The immense lawn is getting mowed.

The flag in the distance is at half mast, but I don't suppose it has anything to do with the quiet botanical battles going on.

American chestnut, sacked by an imported sac fungus 100 years ago, has been making a slow comeback thanks to breeders who have been patiently breeding native trees with resistance. Four of these hybrids (15/16th native, 1/16 Japanese chestnut) were planted at the Battlefield two years ago by local nut tree specialist Bill Sachs.

He said their chances of being resistant to the fungus are about 50/50, and as it turns out two of the trees have developed the symptoms of chestnut blight.

Here's what the stem with the canker looks like. (Thanks to Bill for these two photos.)

The two others continue to prosper, and have grown to 12 feet tall. That they are growing near infected trees gives some hope that they will prove to have inherited resistance.

Several mature non-native chestnuts grow near the Clark House. The shiny leaf on the right is likely a Chinese chestnut, compared to the duller surface of the native species.

Flipped over, the Chinese chestnut leaf has a silvery tinge.

Another battle is going on where two flowering dogwood trees grow along woods' edge to the left of the pillars. If they haven't flowered as profusely in recent years, it may be because they are being completely overwhelmed by what I call "the kudzu of the north", porcelain berry.

Judging from this one small branch reaching out from the thronging vines, like a hand pleading for help, the dogwoods are not far from a full surrender.

Another dogwood close by is getting overwhelmed by wild grape.

Three beautiful dogwoods could be saved by five minutes of horticultural heroism with a pair of loppers, but I doubt anyone has even noticed this botanical battle in full swing. We see here a theme reenacted endlessly on our public lands. The voluminous grass gets mowed, some weeds get whipped, but any maintenance task requiring plant knowledge is left to chance.

A fuller story of chestnuts in Princeton can be found by searching this blog for "chestnut", or clicking on this: http://princetonnaturenotes.blogspot.com/search?q=chestnut.

Photos From a Spirited Cleanup Day at the Princeton Battlefield

Each year, the Princeton Battlefield Society teams up with the local Sierra Club to host a spring cleanup day at the Battlefield. My role the past couple years has been to lead some of the volunteers on work to clear vines and brush around some dogwood trees planted in 1976--the year of the nation's bicentennial. They line the edge of the lawn on the north (column) side of Mercer Street. As with any planting, some followup is necessary, and the state limits its maintenance to lawn mowing. Many of the dogwoods have had to withstand the smothering embrace of aggressive vines like porcelainberry, and bombardments of branches as towering pines lose their lower limbs in snow storms, making our yearly interventions feel like a rescue operation.

The cleanup days always begin with a group photo in front of the Clark House that adds a wonderful sense of place to all the open space around it. This year, while assembling for the shot, we momentarily lost focus when someone spotted a red-tailed hawk flying to a nearby tree, carrying a small snake. Nature and culture in close proximity--that's one of the charms of Princeton, though the snake might disagree.

It was the first nice spring day of the season, which added to our spirited work of lopping, sawing and dragging. There were a lot of good trees to rescue from the vines: cherries, oaks, and of course the bicentennial dogwoods.

A lot of learning happens at these workdays, as volunteers become familiar with some of the plants being saved or removed. Here are the flower buds of the flowering dogwoods, still dormant but poised to open. Their blooms in turn will form nutritional berries for migrating birds in the fall.

Hopefully the state crews will chip up the brushpiles we made.

This boy was very proud of having opened up a pathway that had been blocked by a young tree bent low by a burden of aggressive vines.

An invasive shrub (Honeysuckle) was smothered in invasive vines (porcelainberry). The easiest way to extract it was by cutting it at the base and "rolling" it out of the sea of vines.

Clearing the field's edge of brush uncovered some daffodils that had been planted long ago. We left the wineberries and blackberries in hopes of a crop during the summer.

We finished the afternoon encouraged, by progress that built on last year's progress, by each other's good company, and by the feeling of participation in caring for hallowed ground. Here's our merry crew.

On 11.11.11, Some Princeton Trees

In honor of 11.11.11--a uniquely unique, highly vertical day--some Princeton trees of note, in no particular order:

The brilliant red maples at Princeton Shopping Center in a photo taken today, with Fothergilla shrubs adding orange in the foreground;

A clock tower looking very one-ish today next to the trees;

A photo my daughter took beneath a red oak in the backyard;

A descendant of the famous Mercer Oak at the Princeton Battlefield;

A 15/16th native chestnut planted at Princeton Battlefield in front of the Clark House;

A hican behind Clark House, showing the change in bark where a pecan/hickory hybrid was grafted to a hickory base.

Another red maple, planted by a couple in honor of their newborn son at Potts Park in the borough, positioned to shade the play equipment in future years;

And in memorium, a photo sent to me by Eric Tazelaar, of the old, old white oak near the driveway to Mountain Lakes House, before it was blown down this year during Hurricane Irene (see Oct. 28 post).

Mile-a-Minute Spreading into Princeton

 One of the more noxious invasive plants that has been spreading across NJ is Mile-a-Minute. It's a prickly vine that, though an annual that must grow back from seed each spring, grows so fast that it can cover large areas of roadsides and field edges. Over the past several years, I've been knocking out small infestations at the Princeton Battlefield and near Rogers Refuge, but this year I'm finding new patches springing up around town.

Then, driving my daughter to MarketFair along Canal Pointe Blvd a week ago, I saw a massive infestation that surely is a major source of the seeds that birds are then spreading across Princeton. 

The vine has a distinctive triangular leaf. Berries are just beginning to ripen. If you encounter it, put some gloves on, pull it out and put it in the trash. Putting it in the compost would allow the seeds to spread. 

The infestation along Canal Pointe Blvd is behind 701 Carnegie Center Drive. In the aerial, you can see rows of solar panels over the parking lot. To the left of the solar panels is a big mowed lawn, and to the left of the lawn in the photo is the unmowed land upon which the Mile a Minute is growing. My friend Peter researched the owner, which on the deed appears to be "BXP Carnegie Owner, LLC%G". The land has a farm easement, so is only valued at $39,000, which means the owner is paying next to no taxes to hold very valuable property, meanwhile expediting the spread of Mile a Minute and the associated nuisance it will cause. 

It's hard to photograph the cocktail of invasive species at the site. The white flowers are of white snakeroot, a native wildflower, which is besieged by a layer cake of stiltgrass, porcelainberry, and Mile a Minute climbing on top of it all. 

Further down the road is a series of trees damaged, perhaps by a small tornado or similar localized intense winds as the remains of Hurricane Ida came through on Sept. 1. Similar damage to trees was seen in Princeton Battlefield, where a row of mature white pines along the edge of the field was decapitated.

What we're seeing is the increasing impact of plants out of place (species that turn invasive after being introduced from other continents) and carbon out of place (carbon fuels extracted from underground that we burn, thereby releasing additional carbon dioxide into the atmosphere). Our machines have increased global warming CO2 by a whopping 50% over pre-industrial levels thus far. This year has felt like a radicalization of both invasive species and climate change. 

Inventory at Princeton Battlefield this Sunday, 2pm

This Sunday, July 6, I thought it would be fun to do a plant inventory at Princeton Battlefield, where an 18th century encampment will be in place for the weekend (http://www.saveprincetonbattlefield.org/newsEvents/1783/index.php). We'll meet at 2pm, and work the fringes, away from the encampment. We may also head down into the nearby Institute Woods, time permitting.

Park in the lot or along Mercer, and meet between Clark House and the barn, close to where the remains of the famed Mercer Oak lie moldering in the woods.

This weekly series of plant inventories is being sponsored by Friends of Princeton Open Space. The inventories will be compiled and published in the Princeton Environmental Resource Inventory later this year.

Engaging Bamboo at Princeton Battlefield, Part 2

The Princeton Battlefield Society has an issue with the bamboo that was planted long ago near Clark House. It's expanded to the point that it's starting to block pathways. Responding with a workday in the spring, the volunteers had a big above-ground impact, reducing the forest of bamboo to long piles of thick stems. I made the case that, despite that great accomplishment, it was not time to declare victory. A month later, the bamboo would quietly send up a new forest of shoots from energy reserves in its massive root system, and restore its strength over the long summer.

From high atop my horse, or at least my horticultural soapbox, I offered a plan to outsmart a grass species long schooled in the art of survival. We'd wait until its new stems are ten feet tall, then seize the day, along with some loppers, and cut them all down. That's just what board members Kip and Marc did this past weekend, with an admirable sense of thoroughness. Now it's the bamboo's move. Having spent all that root energy for no return, it may abandon ambitions of tall stems for the time being and merely send up short, shrubby sprigs dense with leaves. If these, too, get cut down, then the bamboo's roots will be well along the way to being exhausted.

We found a few natives growing in the void left by removing the bamboo: spicebush, blackberry, black raspberry, jewelweed, and white snakeroot. Their presence is heartening, and though we discussed encouraging them it's too early to think about nurturing the peace. The bamboo is not yet quelled, and porcelainberry vines are creeping in from the sides, ready to outcompete the relatively tame natives.

We then headed across the backyard of the Clark House to check out another clone blocking another trail. We tasted a young bamboo shoot or two. Not bad, even raw. Maybe what we have here is a failure to utilize. If only Princeton had a ravishing hunger for locally grown bamboo shoots, the clones would be held nicely in check.

Meanwhile, on the other side of Mercer Street, the dogwood trees lining the field are growing new leaves that can actually get sunlight, now that they've been liberated from suffocating vines.

All of this speaks to the progress that can be made in local parks by a few people with some plant knowledge, some strategy, a few spare hours, and some loppers.

Mile a Minute: New Invasive in Princeton

Keep your eye out for this one. It's a vine that's easy to identify, with a triangular leaf, prickly stem, rapid growth. Pull it out, preferably before it makes its small blue berries, or it will grow like a veil over your plantings. Put it in the trash, not someplace where it will get composted and potentially spread.

Last year, I spotted it and removed it from two locations--along the gravel road to Rogers Refuge and along the edge of the north field at Princeton Battlefield--but not before it had made berries to grow a new batch this spring.

In an ideal world, someone would be paid to, among other things, take early action to prevent a new highly invasive species from getting established in town. This year, Princeton will have, for the first time, a couple temporary workers focused on invasive species removal in town preserves. But that doesn't include state properties like the battlefield.