News from the preserves, parks and backyards of Princeton, NJ. The website aims to acquaint Princetonians with our shared natural heritage and the benefits of restoring native diversity and beauty to the many preserved lands in and around Princeton.
Each spring in Herrontown Woods, from April through May, we take part in the Great Garlic Mustard Pull. That's the effort, replicated in yards and nature preserves throughout the eastern U.S., to pull garlic mustard (Alliaria petiolata) out of the ground before it goes to seed. This post explores the logic, toils and unexpected pleasures, as well as the strategies that can make this annual gardening task easier each year.
We pull this nonnative invasive plant, with its aroma of garlic and mustard, because the alternative is too much to bear. Left unchecked, garlic mustard can take over a woodland or garden, altering soil chemistry and smothering native species.
People pulling the flower stems are surprised to learn that other, lower-growing plants coating the ground are also garlic mustard. Two very different forms of the plant are present at the same time. Unlike most herbaceous plants that are either annuals or perennials, garlic mustard is a biennial. That means it grows a rosette the first year, storing energy in its roots--energy that will be used the second year to send up seed-bearing stalks. After the stalk blooms and the blooms turn to seed, the plant dies, leaving copious seed for future generations.
Gardeners are often fooled at first into leaving garlic mustard be. The flowers are modestly attractive, and as they fade and turn into siliques packed with seeds, the plant too fades politely into the background. But wait a month or two, and the flowering stems turn brown, populating the garden with skeletal remains. By the time the gardener notices this blight, the seeds have already dispersed.
Much is made of the plant being edible. Young leaves can be used to make pesto and other dishes. Our friend Kirsten used it to make delicious deviled eggs. But in most situations, the plant's powers of proliferation quickly overwhelm people's appetites.
And so we pull, and pull. That's Herrontown neighbor Philip Smit in the photo. The aim is to get every last one, to ultimately exhaust the soil's supply of seed. Only with zero tolerance will the task get easier year to year. Here is where technique and timing come into play. If you pull hastily, or when the soil is dry, you may get the stem but not the root. This is an incomplete victory. That root will sprout new seedstalks that then too must be pulled. So we "grab low and pull slow", ideally pulling after rain has softened the soil, and return a week or two later to check for any resprouts.
And what to do with the pulled stems? Bagging them is a lot of work and wastes energy to have them hauled away. This year, we've been putting them in trash bins, then rolling them to a pile. In case any of the seeds mature, the pile is located where the seeds won't wash down the hill, and any seedlings will all be in one spot.
I've heard stories of gardeners who pulled year after year, and yet the garlic mustard continued to sprout anew. Where would the seed come from? We speculated that erosion from heavy rains, or the diggings of squirrels, could expose long buried seed.
But another cause could be these miniature plants I've been finding. We pull the bigger plants and think our work done, but no. A second and even a third pass is needed over the course of weeks, with an eye out for these tiny plants.
There can be pleasure in the task. These two visitors to the preserve joined in one day. Kids, too, take to the pulling, seeking out the white blooms as if it were an Easter egg hunt.
We're grateful that some students from Princeton University's Outdoor Action--Will Aepli, Quest Starkey, and Zach Duscorsky--worked with Ben Schaffer and me to clear garlic mustard from the Veblen House grounds and the Barden. Inge Regan, Moss Gordon, Ninfa and Andrew have helped with a larger patch in another woodland we're restoring.
Invasive species can seem an impossible challenge, but if the invasion is caught early, and the garlic mustard is completely removed year after year, even the task of protecting 230 acres of public open space at Herrontown Woods and Autumn Hill Reservation becomes doable, with some satisfaction and even pleasure in the task.
This year, we're getting more organized about planting and growing sunchokes. They are also called Jerusalem artichokes, which is a persistent name despite their not being artichokes and not being from Jerusalem. Instead, they are a native sunflower species, Helianthus tuberosus. As the latin name implies, they combine the height and glorious blooms of a sunflower with edible tubers that have a nutty flavor.
Sunchokes are super productive, but also spread aggressively underground, which means that they could easily take over your garden if not constrained. Thus the idea of planting them in big plant pots, and setting them on cardboard as further assurance that the roots won't sneak out the bottom of the pots and start spreading into the garden.
With good soil, sun, and water, you may end up in late fall with a tub packed with sunchoke tubers. Then the question is how to get them out of the heavy tub, a few at a time. The clever but untested answer I came up with years ago is to cut the dead stems in late fall, turn the tub over, then leave it upside down through the winter. Upside down, the tub becomes a cover that can be lifted whenever you want an artichoke to eat raw or cook. This year, it looks like we might get organized enough to see if this approach works.
Here's a plant pot filled with the harvest this spring from last year's big black tub. I expect that more attention and prep will, as in past years, yield far more.
My source for tubers has been the produce section of the Whole Earth Center in Princeton. There's another variety, with reddish, more linear tubers, that I also have. Both taste good.
The journey of this blogpost began with a curious lone tree found standing along Nassau Street in late winter. I had passed by this spot many times, oblivious to what has long been there, tucked away in a courtyard.
Perhaps 20 feet tall and all knobby at the ends, the tree's silhouette looks more like something you'd see in Joshua Tree National Park than downtown Princeton, New Jersey. And those stubs of branches sticking out look more like a way to keep pigeons away than launchpads for new growth.
Though I have yet to inquire, it looks like someone cuts this tree each year at the same spot, so that it will stay the same size and not outgrow its confined space in the courtyard. Anyone who has traveled to Europe has likely seen this radical pruning of trees. Is this a form of torture or a clever and sustainable means of manipulating growth?
Meanwhile, in my front yard, there's a native shrub called a buttonbush that began to outgrow the spot where I planted it. Fortunately, buttonbush flowers on new growth, so you can cut it down as far as you want each winter and still get abundant flowers for pollinators in the summer.
Here's what it looked like before I cut all those long stems off to get it back to a manageable size next to the sidewalk.
I pruned another one in the backyard even more radically--almost down to a stump. And those long shoots I cut off, gathered on the right side of the photo? Those I use as "live stakes" to create new shrubs in the nature preserve we take care of, Herrontown Woods. Buttonbush, like the native silky dogwood and elderberry, has the wonderful quality of sprouting roots when pushed down into moist ground in late winter. Clip the above ground portion down to a couple nodes, where leaves will sprout. Easiest and cheapest new shrub ever, as long as you water it during droughts and protect it from the deer.
My radical pruning, then, serves two purposes. It keeps the shrub small, and produces a crop of highly useful live stakes for propagation.
By harvesting these live stakes, I was practicing a form of radical, recurrent pruning that dates back thousands of years, was once common worldwide, and has a name: pollarding. I've written about it before (see links below), but decided to cruise the internet in search of more info.
What I found were some delightful short videos produced in Norway that tell the story of pollarding and a related practice, coppicing, in a way that changed my view of Europe's relationship to nature. You see, I have long thought of Native Americans as being the ones who managed the land in a way that promoted biodiversity. Lacking saws and sharp axes, they primarily used fire--the low-level variety that I like to call mildfire--to open up canopies and promote lush growth of useful plants in the understory. Mildfires promoted the growth of fire-resistant, food-producing trees like chestnut and oak, while opening the canopy enough to allow sunlight to drive production of edible herbaceous plants and berry-producing shrubs like blueberries. These managed forests were likely far more productive and diverse than our dense "untouched" forests that may work for some species, but whose deep shade limits what can grow in the understory.
What I didn't realize, in this elevation of Native Americans as ecologically minded land managers, was that Europeans also had ancient ways of managing land that promoted biodiversity. Watch these animated 4-minute videos and you'll learn that the farmers' practices of radical pruning known as pollarding and coppicing allowed trees to live long and productive lives while also allowing sunlight to reach more diminutive but equally important plants. Coppicing and pollarding even proved beneficial for insects and birds.
The videos evoke a time when culture was married to local nature. There was an enduring relationship, a give and take. Year after year, for decades growing into centuries, farmers would tend to the trees. Unlike a typical forest today, in which most of the sunlight feeds growth far beyond reach, pollarding kept the trees' productive canopies closer to the ground, kept the branches smaller and easily cut so that the leaves could be fed to animals and the branches used for tools, poles, and firewood. To work, pollarding depends on consistent tending--a hardwired connection between people and nature.
Though I still encounter that hardwired connection in some people, more common is a relationship to nature that is distant, fleeting, and abstract--more aspirational than actual. Organized gatherings to plant a tree or a raingarden tend to be like one night stands, with little or no followup to insure that whatever was planted actually survives. While we import sustenance and lumber from distant lands, the local trees are called upon to provide services that are more sensory and psychological: to cool our air, heal our souls, and somehow miraculously compensate for our relentless injections of additional carbon dioxide into the atmosphere through tailpipes and chimneys. So disconnected is the economy from local trees that, when they are cut down, trees are immediately ground into woodchips, ironically expediting the return of their sequestered carbon to the atmosphere.
As the videos show, pollarding in past centuries not only made tree canopies accessible and useful. Harvesting branches in a grove of pollarded trees every 10-15 years allowed sunlight to reach the ground and power the growth of diverse understory species. Though we allow trees to grow naturally in local woodlands, we have limited our open space to only two options: the land is either a forest or a field, no inbetween. The inbetween is what would have been more common historically, when fire was allowed to play its ecological role in creating a mosaic of old-growth and younger landscapes. Pollarding appears to have been a way to replicate a more natural, ecologically diverse mosaic while directly sustaining a human community.
Now, if you check in with an American arborist about pollarding, you'll likely get a negative spin. Here's an informative example from Oregon of an American approach to tree care that promotes useful interventions like weight reduction, crown thinning, crown raising, and crown reduction. These methods of pruning preserve a tree's naturalistic growth patterns and shape. The practice of pollarding is also mentioned, but is placed at the bottom, and criticized as stressful for the tree, unnatural, unsustainable, unappealing, and leading to weak branch structure, instability and shorter lifespan.
This negative take on pollarding in the U.S. conflicts with the descriptions in the videos, which tell of coppiced or pollarded trees living for many hundreds of years and proving more resilient in storms. It also conflicts with my experience in North Carolina. When a hurricane swept through it was the pollarded willow oak that proved most resilient. Its many thin flexible branches swayed in the intense winds, while more naturally growing willow oaks with their bulky frames and massive canopies proved vulnerable. The trauma inflicted by that storm caused me to view natural-growing trees in our neighborhood differently--still as generous beauties but also as wild, untamed beasts we allow to grow amongst our houses.
As described in the videos, success in pollarding and coppicing depends not only on consistent care but also on the kind of tree. For coppicing, the video mentions European hornbeam, linden, chestnut, and hazel (Carpinus betulus, Tilia sp., Castanea sativa, Corylus avellana). There are American parallels to these: ironwood, basswood, chestnut (at least in the past), and hazelnut. For pollarding, another source suggests willows, London plane tree (related to our sycamore), American basswood, elms, and mulberries.
A culture such as ours, distracted and disconnected from nature, is not likely to foster healthy pollarded groves of trees like the farmers on the hillsides of Norway. But in a town where the open space movement was founded by a man whose last name comes from a farm in Norway, Oswald Veblen, it's worth demonstrating these forgotten methods of collaborating with nature. The sprout-happy buttonbush and a lonely tree on Nassau St are a good start.
Though the high ground in northern Princeton known as the Princeton ridge may not live up to the "mountain" in Mountain Lakes and Mount Lucas Road, that igneous upwelling 200 million years ago makes for some fascinating geology underpinning the town.
On Sunday morning, May 3, at 11am, Laurel Goodell and grad students Theo Green and Josh Isaacs of Princeton University’s Department of Geosciences will lead a geology walk at Herrontown Woods. They'll explain the origins of the many diabase boulders, the presence of magnetic rocks, and other special features. We may even hear about the weather and soil station installed years back at the Barden. In honor of Earthday, the walk will be free.
Preceding the walk, starting at 9:00am, will be the monthly May's Cafe with coffee, tea, and baked treats at the Botanical Art Garden ("Barden") in Herrontown Woods at 600 Snowden Lane.
Adding to the creativity and fun at the cafe, artist and FOHW board member Hope VanClef will host a workshop, in which participants can decorate tiles that will become part of a Community Collage. Follow the link to sign up.
This post about aquatic life in Princeton begins with a hawk. Spotted and photographed by volunteer Mariah on April 4, about 100 feet downstream of the red trail's stream crossing at Herrontown Woods, it was not soaring or perching on a branch as hawks typically would, but instead was standing very still on the ground at the edge of the stream, peering into the water.
What was it looking for? My thoughts immediately went to the day we were startled by the thrashing of several foot-long fish as we crossed the stream on that very trail on that very day one year prior. Might predators know its time for the spring migration of fish up into Herrontown Woods to spawn?
Whether due to lack of serendipitous timing, or lower water levels, we saw no return of the foot-long white suckers this year, but yesterday a visitor to the woods named Brian told me he had seen fish down at the stream.
I went down to have a look, and this is what I found, about six inches long. I tried my best to take some photos before releasing it back into the cool, clear waters that flow from the headwaters preserved within Herrontown Woods.
Its mouth didn't look as downturned as those on the white suckers we saw last year. What could it be?
Those horny bumps on the head and some internet research led to creek chubs (Semotilus atromaculatus). The bumps are called tubercles, found only on the males during mating season. One cool thing about chubs in general is that the males build nests made of stone, then entice a female to lay her eggs there. The nests can be quite elaborate, and are so well guarded by the male that females of other fish species may take advantage of the free security by laying their eggs there as well.
Googling horns on the head, I had initially encountered a related fish called the hornyhead chub. Who knew that Newborn, Georgia hosts a Hornyhead Fish Festival each year. My respect for the fish, and chubs in general, grew as I read this fascinating account of the male hornyhead's nest building expertise, assembling surprisingly large rocks from the streambed into elaborate structures to protect the eggs.
Such testimonials stir memories of the round depressions sunfish would make in the shallow waters of the lake near Hayward, Wisconsin where my family would journey each spring to set up the tents for a Girlscout camp. It may also be worth taking a closer look in local streams for circular stone structures fashioned by creek chubs.
As a land manager and gardener who has long catered indirectly to the needs of insects, I emerged from this hour and forty five minute documentary with a deep sense of both gratitude and frustration. The film excels at revealing the beauty and diversity of insects, yet is inexplicably dismissive towards several factors that are likely driving the dramatic decline in their numbers.
First, some of the many positives. As the film introduces us to the mind-boggling diversity of the insect world, it also provides portraits of a memorable cast of characters who show their steadfast love for insects in varied ways. The film is dedicated to E.O. Wilson, and apparently takes its title from an article Wilson wrote in 1986. In one scene in this documentary, we see the preeminent entomologist in his last year or years, still mobile enough to comb a gentrified suburban landscape with a net, in search of insects to show us. Fittingly for the theme of the movie, he finds none. In the 21st century, I've seen the great environmentalists of our era age while civilization continues stubbornly down its self-destructive path. Wilson provides a dramatic example, his right eye drooped to a close as if part of him really doesn't want to see what's happening to the natural world he has devoted his vigorous life to studying.
There are so many fascinating human portraits in this film, and so many ways to love insects: by photographing their otherworldly micro-features with a powerful camera, or steadfastly building decades of data on their numbers. Other researchers accumulate countless trays of countless tiny bees all lined up, each skewered with a pin, awaiting someone with the passion and curiosity to study their features. We visit a gardener who gradually dug up his lawn to plant wildflowers until there was no lawn left.
In the film, director Doug Hawes-Davis visits backyards and farms where insects and the plant diversity that supports them are valued and nurtured. Then, with the help of drone photography, he occasionally lifts us up and over the landscape to see how one nature lover's diverse plot of land is dwarfed by the anti-nature world of buildings, roads, and lawns that surrounds it. Vistas of vast almond plantations, sterile country club developments, and corn fields drive home the massive scale of simplified landscapes that have displaced complex nature.
Why does the film visit the almond plantations in California? Because early each year beekeepers truck more than 80% of all U.S. honeybees to one area of California on semi-trailers to pollinate those almond trees. The high quality pollen and nectar from the almond flowers gives the bees an early feast, but the annual mass gathering also serves as a giant spreader event for disease and pathogens increasingly afflicting honeybee populations. We also travel to Germany, where a longterm study using appropriately named Malaise traps documented a 76% drop in insect biomass over 27 years. There are other signs of declining insect numbers. Some species of bumblebees once common in the eastern U.S. have disappeared altogether. Windshields are no longer splattered with insects.
The movie's website promises insight into cause:
What is causing this extinction crisis? What can be done to reverse the trend? The Little Things that Run the World attempts to find answers to those questions and more.
But it is here that the film falls short. Yes, today's farms and lawns are far larger and more sterile than in the past. Development has usurped and fragmented habitat. But the film barely mentions climate change, and no reference is made to invasive species other than when a few volunteers are filmed naively hacking at a patch of Phragmitis--a manual approach to fighting this pernicious invasive plant that is doomed to failure. Though some pesticides surely play a role in insect decline, the film vilifies them all, including the low-toxicity herbicides that no manager of native habitat could possibly do without--any more than a doctor can effectively practice medicine without medicine. In this way, the film contradicts E.O. Wilson himself.
The film could have considered other potential causes of insect decline--for instance the increase in the number of deer, whose appetites have erased the varied native understory vegetation that herbivorous insects need to survive. It's worth noting that the film seldom ventures into forests. Deep shade suppresses the sorts of wildflowers and shrubs that can sustain pollinators through the summer months. In this way, the massive succession of the eastern U.S. from fields to dense second-growth forests over the past century may be a mixed blessing.
A lot of environmental threats can be characterized as "too much of a good thing." There's too much carbon dioxide in the atmosphere, too many deer, too many of this or that introduced species. Some types of herbicides, like medicine, can be helpful in small amounts, harmful if overused. There can even be too many trees stealing sunlight from the more diminutive species pollinators need.
Devoting quality time to memorable portraits of people, the film neglected to use its powers of visualization to document important drivers of insect decline: vast stretches of invasive species, a forest understory stripped of native plants by deer, and the stress of increasingly radical swings in weather, be they from deluge to drought or from hot to cold to searing hot again. While rightly questioning the simplified suburban landscapes that cheat insects of habitat, the film left unchallenged the comforting and crippling environmental orthodoxy that trees are all good and pesticides all bad.
The film is definitely worth seeing for all its strengths, but the seemingly willful false narrative about cause is reason to follow it with a discussion of all the likely drivers of insect decline left unmentioned.
For many people who have a yard to take care of, concern about the ultra invasive lesser celandine can lead to stepping outside to take a closer look at what's growing out there.
This is a plant that seems pretty at first, then becomes a menace as it spreads through your lawn and flower beds, then into your neighbor's yard and the local nature preserve.
Here's an advanced invasion of a lawn at Pettoranello Gardens.
As you hopefully act to eliminate it from your yard, most practically with a spray bottle in hand, suddenly there's a motivation to distinguish one little plant from another.
This post will help you make those distinctions between lesser celandine (also called fig buttercup) and other similar-looking plants, and in so doing use as little spray as possible.
First, a few photos of lesser celandine in its various forms.
It can have a lot of petals, but unlike dandelions, they are distinct petals.
By mid-April, the flowers are fading away, so take a good look at the leaf. Invasion of your yard begins with little benign-looking clumps like this, here and there. It doesn't look threatening, but this is by far the best time to act.
Lesser celandine will likely be pretty obvious to you, but if you've been eradicating it each year and are down to a few, it's useful to know other plants that look similar.
Here's garlic mustard. Notice the scalloped, wrinkled look to the leaves, a bluish tinge, and the strong mustardy aroma. Unlike lesser celandine, which has deeply entrenched roots and no clear rosette, you can gather the basal leaves of a garlic mustard in your hand and pull it out of the ground--something really good to do before it goes to seed, because it too can spread and begin to take over. The smaller leaves closer to the ground in the photo are mock strawberry. See below.
Mock strawberry, a nonnative that can spread in annoying ways, via stolons, through your garden and lawn, has a yellow flower, but only five petals. Note the distinctive leaves, which are composed of three leaflets.
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Dandelions, too, have a yellow flower this time of year, but you'll see that the dandelion flower doesn't have those distinct petals, and the leaves are not round but instead linear and deeply lobed. Dandelions will invade your yard, but not the local nature preserve.
Violet leaves are probably the easiest to confuse with lesser celandine. Notice the arc-shaped veins in the leaves, which lesser celandine lacks. The violet leaves may also be duller--less glossy--than the lesser celandine leaves. Violet leaves and flowers, by the way, are tasty in salads or steamed, so its well worth getting to know them.
Here's a typical violet flower.
Scrutinize this photo a bit. Lower down is the lesser celandine, but in the upper right are two leaves that are similar to lesser celandine, but are more elongated and have ribbing on the leaf surface.
Here's a cluster of leaves of that other plant that isn't lesser celandine. I don't have a name for it yet.
If you happen upon this one, you've found woodland aster, a native that has white flowers in the fall.
Sometimes I encounter a delicate, usually solitary plant whose basal leaves can look a bit like lesser celandine but with a subtly different shape.
As it grows, it sends up some creatively shaped avant garde leaves and bears some tiny yellow flowers. I have preliminarily identified it as small-flowered buttercup. It doesn't have the robust, dense growth form of lesser celandine.
These are the lookalikes that I have encountered. Knowing them helps me use as little herbicide as possible, and save the other plants that increase diversity rather than form monocultures of a toxic plant that's inedible to wildlife.
One more photo showing how those first, benign-looking clumps of lesser celandine, if not dealt with early, will continue to spread and merge into one giant mass that looks like green pavement.
A note about herbicides: Many people are reluctant to use herbicide, but a yard is not an organic farm. You can't mulch or cultivate a lawn or flower bed, or a nature preserve, for that matter. The undesired is embedded in the desired, much like infections in your body. You can certainly try to dig up lesser celandine (don't leave any roots in the ground, and throw the diggings in the trash, not the compost), or torch it, or spray vinegar solution. Better results will likely come, however, from targeted, minimalist use of systemic herbicide that kills the roots. It's unfortunate that some have imposed a blanket condemnation on all herbicides, regardless of their individual characteristics. Think of the spray not as poison but as medicine. We routinely use medicines of varied and known toxicities in our bodies. When seeking to heal ourselves, we catch infections early and use as little medicine as possible to get the job done, and it's the same when sparing nature from invasions. The earlier you catch the invasion, the less herbicide needed, so don't delay.
The eggs are laid in the vernal pools. The frogs and salamanders have scattered into the nearby woods. They migrated later than usual this year, delayed first by snow drifts that lined the road where they normally cross to reach their vernal pools. But the snow melted and along came a few relatively warm, rainy nights to lubricate their movement across the road and through the forest.
Long before the annual spring migration of woodfrogs, spring peepers, and spotted salamanders began, the weather was being closely watched by the Princeton Salamander Crossing Brigade, a group founded by Inge Regan, a board member with the Friends of Herrontown Woods. Volunteers attend late-winter training sessions at the Sourlands and elsewhere, then benefit from the expertise of Brigade members Mark Manning, Fairfax Hutter, Lisa Boulanger, and Mark Eastburn.
The work of the Salamander Brigade, now in its fourth year of helping amphibians safely cross the road, was greatly helped by a collaboration this year with the Princeton Police Department, which has placed blockades across the road during rainy nights. The blockades reduced car traffic almost to zero, allowing the vast majority of amphibians to safely cross the road.
As described in some excellent CBS News coverage earlier this week, traffic in previous years led to the loss of up to 40% of the amphibians, despite the valiant efforts of the Brigade to help them across.
This year, Brigade members met at dusk on four different nights, in raincoats and reflective vests, with powerful flashlights to monitor and document the migration.
Those who had never held a salamander got the joy of doing so.
It's not always easy to take notes on weather and amphibian numbers out on a roadside in the rain. It helps that Dr. Regan has long experience writing up charts for patients. The data gets sent to the Sourlands Conservancy, then on to the state wildlife agency.
Over four evenings, volunteers counted 40 spotted salamanders, 7 woodfrogs, and 52 spring peepers.
Those raucous spring peepers you hear in spring are incredibly tiny.
The spring peepers seem to be doing okay, but the low number of woodfrogs is concerning. Last year there were dramatically fewer woodfrog egg masses in the main vernal pool in Herrontown Woods, and this year again they are greatly reduced. In June last year, there was a mass dieoff of tadpoles in another pool. A Rutgers professor studying wildlife diseases said ranavirus has been hitting some populations in NJ.
That pool, not far from the main parking lot of Herrontown Woods, fortunately has lots of eggs again this year, both woodfrog and the whitish clusters of salamander eggs.
One of the more comic moments was the spotting of a male woodfrog trying to mate with a salamander. The salamander wanted nothing to do with it. In fact, the salamanders don't directly mate. Rather, the males show up at a vernal pool ahead of time, deposit spermatophores, then wait for the females to come along to pick them up. The system seems farfetched, but the proof is in the eggs that will soon hatch. Hopefully, the vernal pools will keep enough water to sustain the tadpoles and salamander larvae as they grow to adulthood in these little oases in Herrontown Woods.
Volunteer Cozy Sierra caught the spirit of the Princeton Salamander Crossing Brigade in a t-shirt she had made.
Word is out about the Princeton Salamander Crossing Brigade, founded by Friends of Herrontown Woods board member Inge Regan in 2023. On Monday, March 23, CBS News New York came a'knockin' and ended up interviewing Inge and Herrontown neighbor Lisa Boulanger about the work volunteers are doing to help salamanders and frogs safely cross the road during their spring migration to nearby vernal pools. The Princeton Police Department is also featured, having played a critical role this year by closing the road during the warm, rainy early spring nights when amphibians are on the move. Amazing how quickly the news team can generate a fine portrait of our activities.
Last June, I was driving down Herrontown Road when I noticed something very unusual. Scientist Louis Pasteur once said that "Opportunity favors the prepared mind," and that's certainly true in this case. My mind was very well prepared to notice that one of the trees growing in front of a house was healthy while those on either side of it were not.
Just six months prior, I had researched and written a post entitled Seeking "Lingering Trees"--Some Hope for Ash and Beech Trees. The post encouraged readers to keep an eye out for lingering trees, i.e. ash or beech that were still looking healthy while those around them were dying. And here, along Herrontown Road, I witnessed the very phenomenon I had read and written about.
That line of tall trees is all ash trees. All but one have succumbed to the depredations of the introduced insect called Emerald Ash Borer (EAB) that has been devastating millions, more likely billions, of ash throughout the eastern U.S.. Not having co-evolved, our native ash tree species lack resistance to this nonnative insect. Hitchhiking into Michigan in wooden packing crates from China in the 1990s, EAB spread eastward arriving in Princeton in 2015. What ten years ago was Princeton's most common native tree is quickly becoming its most rare, impacting all the fauna dependent upon it for food.
But here, in this area of northeastern Princeton, there's some conspicuous survival going on. These two healthy-looking ash were growing near the first one I saw.
Though it's hard to say at this point whether these are true survivors, this would not be the first time Princeton played host to native trees unusually resistant to introduced insects and disease. There's the "Princeton" variety of American elm that has shown resistance to Dutch Elm Disease. And we're having some luck thus far with bringing back the native butternut from nuts gathered from two lingering trees then growing on the Textile Research Institute property overlooking Carnegie Lake. Butternuts have been laid low by an introduced canker disease.
Unfortunately, we'll never find out if two of those lingering ash along Herrontown Road might have survived. They were cut down by a tree company yesterday. Last fall, I had knocked on the door to alert the owner to the remarkable surviving qualities of their ash trees. No one was home, and I forgot to follow up. Sometimes, I get the feeling like there are holes in the universe where I was supposed to be.
I've reached out to the town arborist and open space manager, to see if there's any way "lingering" trees could be inventoried, and homeowners encouraged to protect them, so that any local resistance can be given a chance.
Update: Princeton's arborist emailed me the following:
"At this time, the ordinance permits the removal of all ash trees with no questions asked regardless of condition or history of injection."
Update, 3/26: Rachel Kappler, whose Ohio-based research into resistant strains of native beech and ash I have written about, sent the following advice for people encountering "lingering" ash and beech:
I am one of the collaborators assisting with lingering ash reports but in NJ I would focus on reporting them to the Forest Health department of the NJ state forest. You could also use the free phone app Treesnap, which allows scientists to see you entered trees. They end up prioritizing them and contacting owners when samples are needed. Find out more at Treesnap.org
This spring, I'm offering some informal, hands-on native plant workshops at the Princeton Botanical Art Garden ("Barden") in Herrontown Woods. The next one is from 10am to noon this Saturday, March 14, at 600 Snowden Lane.
The first one was last Saturday, and it was such a pleasure to play the role of mentor. New volunteers Angela and Sabrina came, and each took on various projects to cut last year's flower stems and set the stage for a new season. Angela gained introduction to rose mallow hibiscus, the still fragrant stems of wild bergamot, and various others as she went around the "Veblen Circle" of wildflowers, cleaning out the cages. She was thrilled by the site of buds at the base of a cupplant, which led to a conversation about the role imagination plays in gardening. Sabrina cleaned out dead stems from around one of our sculptures, and helped me prep a raingarden where cutleaf coneflower and buttonbush will soon sprout.
The Barden, a forest clearing where sun-loving wildflowers and shrubs can prosper, is a perfect setting for learning about nature and our positive place within it. If you're interested in plants, and want to help out, come by. There's a lot of learning that grows out of doing. It's very informal at this point. Check the HerrontownWoods.org website and Herrontown social media for upcoming sessions. Thus far, they are happening on Saturday mornings starting at 10.
Nature has a new ally in Princeton, a new source of organizational energy that in its initial stages feels transformative. Long active as the organizer of the Hopewell-based NJ Native Plant Swap and other ventures, Kari Lloyd has now come to Princeton as the K-5 STEAM teacher at Littlebrook Elementary, and has brought her organizational energy with her.
Her first event was the Native Seed Sowing Extravaganza, which brought 100+ parents and kids together in the Littlebrook cafeteria to put some seeds in the ground.
It being Feb. 5, the ground came in the form of pre-moistened potting soil.
Kari had lots of well-trained helpers, as families chose from an impressive selection of seeds,
then planted them in plastic gallon milk jugs. Some helpers had gotten jugs by the hundreds from coffee shops, others cut them in half (leaving one corner as a hinge), then partially filled them with potting soil. Others instructed participants in how to scatter their seeds on the soil and tape the jugs back together with packing tape. And don't forget to scribble the name of the plant on the jug. Cost per jug was $5, making the event something of a fundraiser for the school.
There to witness the event were members of a number of longtime Princeton environmental organizations that themselves have been gaining momentum over time--Friends of Princeton Open Space, Sustainable Princeton, and the group I lead, Friends of Herrontown Woods.
Princeton can feel like a cocoon at times, wrapped up in itself. In addition to longtime regional institutions like the Watershed Institute and DR Greenway, a lot of energy and expertise has been gathering in the small towns and countrysides beyond Princeton's borders. While Princeton has its Friends groups--FOPOS and FOHW, and the lesser known FoRR--Hopewell has its FOHVOS, short for Friends of Hopewell Valley Open Space. We've benefitted in the past from periodic visits from the FOHVOS NJ Invasive Species Strike Team, but Kari is the first to my knowledge to plant herself firmly in Princeton, and bring all that wonderful nearby environmental energy to town.
She arrives at a time when Princeton has made great strides in preserving the last tracts of open space, and has begun to undo decades of neglect as we chip away at the massive invasions of nonnative species on preserved land. But at the same time, there remains a widespread disconnection from nature, where the tending to one's yard is outsourced to crews whose mission is to purge and simplify. There can seem little time or inclination to surround one's home with anything more than grass. Still, there's a sense of momentum in the air. The seeds are in the soil; the milkjugs have been carried home. Hopefully the sprouts will stir curiosity about the plant world, and inspire people to take on the challenge of deciding where to plant them, and remembering to tend to them.
Next on Kari's docket is organizing a series of monthly family hikes in Princeton and Hopewell, beginning with a hike in Herrontown Woods, to be led by myself and Hopewell Valley-based Nicole Langdo, founder of Painted Oak Nature School.
