Coppicing and Pollarding as a Means of Promoting Biodiversity

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.

Related posts:

"Sprout Lands"-- Restoring a More Active Role for People in Nature - a great book

Pollarding in Princeton - examples around town

Controlling Nature in Paris - examples encountered in Paris

The Jazz Naturalist Travels to England - a couple examples in a nature/culture travelogue

Clarifying Certain Pruning Terminology: Thinning, Heading, Pollarding - Some useful distinctions

Geology Walk, May's Cafe, and Community Collage at Herrontown Woods Sunday, May 3

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.

Another Fish Sighting at Herrontown Woods: Creek Chubs

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.

Film Review: The Little Things That Run the World

The following was written after attending a screening of "The Little Things That Run the World" --a fascinating film about insects and their global decline in number and variety--at the 2026 Princeton Environmental Film Festival (PEFF). There don't appear to be any other reviews of the film online.

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.

Related writings:

Reviews of books, articles and opeds denying the threat of invasive species

Lesser Celandine Lookalikes: Which Leaves to Leave

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.

Other related posts:

Will the Real Marsh Marigold Please Stand Up: A Confusion of Yellows

The Herrontown Amphibian Report: 2026

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. 

Why Would CBS News Come to Herrontown Woods? Salamanders!

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.

How to Protect Lingering Ash Trees in Princeton?

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

Native Plant Workshops at Herrontown Woods

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.

Kari Lloyd--Bringing People and Nature Together in Princeton

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.

Maria Pinto Speaks on Mushrooms at Labyrinth Bookstore, 2/19

As reported in TapIntoPrinceton, the Labyrinth Bookstore will be hosting a talk about mushrooms by naturalist, forager, and educator Maria Pinto, Thursday, Feb. 19, at 6pm. 

Ms. Pinto's broad interests in cultural and ecological interconnections inform her approach to this fascinating subject. Our Friends of Herrontown Woods is co-sponsoring the event. More info about Ms. Pinto and a colorful description of her debut book is on the Labyrinth website.

If you type "mushroom" into the search box of this blog (top left corner on a computer), you get various posts about mushrooms. 

End of an Era for Skating on Carnegie Lake?

This post in part seeks to correct misinformation widely disseminated about how often skating has been permitted on Carnegie Lake in the past. See further down.

By chance, I was listening in on this week's Princeton town council meeting via Zoom when the subject of ice skating on Carnegie Lake came up. Turned out that town staff had quietly removed Carnegie Lake last year from the list of potential skating sites. Council member Mia Sacks expressed surprise that council hadn't had an opportunity to discuss the decision. 

Staff explained the logic behind discontinuing what had been a long tradition of permitting skating on the lake when the ice reached sufficient thickness. Parking has become limited; staff testing of the ice involves some risk; and emergency services had concerns about the large size of the area between Washington Rd and Harrison Street where skating had traditionally been permitted. Fear of litigation, and fear that social media would draw large, unmanageable crowds, also drove the decision.

Though the concerns had some logic, there was some misinformation put forward in support. Staff knew of only one time after 1996 that skating had been allowed on the lake, but this blog documents five: 2007, 2009, January 2014, February, 2014, and 2015. (Update, 2/16: A sixth occurred in January, 2003.)

One council member claimed people had died from skating on the ice, but offered only the recollections of a relative as evidence. It's very easy to research this sort of thing. The Papers of Princeton website allows word searches of all papers published in Princeton going back to the 19th century. By typing "death" "carnegie lake" into the search box for Papers of Princeton, 78 results come up. Among the 78 I could find no incidents of death from skating on the lake. There was only one incident of death while ice skating, in 1943, when two boys had unfortunately strayed off of Carnegie Lake and skated upstream on the Millstone River. I found five instances of drowning in the lake or canal, unrelated to skating, between 1985 and 1996, and one obituary that told of the deceased's fondness for skating on the lake. If anyone finds documentation that contradicts the above, please contact me.

There was reference at the meeting to a skating injury on Carnegie Lake that had resulted in a lawsuit. The Town Topics reported that the lawsuit dated back to 1996. Skating has been permitted six times in the thirty years since, so it's not clear why the lawsuit would be taking on relevance now.

At the council meeting, four members of the public described how skating on the lake had been a magical experience for them as kids and adults--one of the things that had made living in Princeton special through the years. They pointed to the new parking garage not far from the lake, and asked if the empty Butler tract could be another parking option. One made the argument that during extraordinary cold spells like this, some people will skate on the lake regardless, so it would be safer to provide safe boundaries.

One unspoken cause of the policy change could potentially be the loss of institutional knowledge. The gap between 2015 and the deep cold of 2026 was long enough to weaken a tradition that, like all traditions, is sustained through repetition. Who on staff could remember all the trouble spots to check and mark off on the lake? 

Skating has been permitted this winter at a small pond at Smoyer Park, but it's not the same.

Though it's conceivable that policy will be reassessed, and at least a small part of Carnegie Lake will be opened to skating if and when we get another sufficiently cold spell in the future, what are the chances that the wonderful tradition will ever be fully revived? For those who weren't around to witness past permitted skatings on the lake, here's a taste of the magical experience that would be missed. 

From Winter in Residence, 2007:

The arctic air blew in and Winter, quietly working in its favorite and most deceptively magical medium, transformed a pretty but otherwise cold and unwelcoming lake into a dancefloor, public square and sports arena. Working without a budget or publicity, nor any tools beyond serendipity and physics, Winter drew thousands of local residents to a spontaneous community festival down at Carnegie Lake.

Rows of cars filled the field; skaters of all abilities plied the wondrously smooth ice. One skater propelled himself with a homemade sail. A baby took to the ice in a baby carriage. Along with some pickup hockey games, there was a slippery, slidey game of soccer played slow-motion in boots.

Sweetgum: Embedded Mysteries of a Tree and Its Rare Paneling

A tree can be many things for many people: beautiful or a nuisance, its wood low-grade or its grain profound. A sweetgum tree is all these things for me. This post will give you a tour through sweetgum's beauties and annoyances, including its surprising use as high-end wood paneling in the 1920s and 30s.

First, regard the beauty. What other tree offers such a panoply of colors in the fall? Yellows, reds, purples, orange--sweetgum does it all. True, those powerful colors are only generated by trees that receive adequate sunlight, but there is some wonderful, creative chemistry going on there. Carotenes, xanthophylls, anthocyanins--these are the words that exercise the tongue while stirring curiosity about the possible purpose behind all that color.

There was a time in my life, during my extended undergraduate career, when I acquired a fascination with chemistry, specifically organic chemistry--the chemistry of carbon, the element upon which life is built. While premeds labored through the lectures with high anxiety for the grade they might receive, I was there with a love of subject and a hunger for knowledge.

In decades since, and not talking about premeds here, I've noticed that people who are disconnected from nature tend to be intimidated by nature's complexity. In order to feel comfortable, they surround themselves with a simplified, static nature of mowed lawn and trimmed shrubs. But for those of us who love nature, its complexity is appealing--a richness that rewards endless inquiry and exploration. I remember a bus ride through New England, probably in my 20s, looking out the window and thrilling at the thought of all the chemistry going on in the forested hillsides we were passing by. 

At the same time, it's hard not to be annoyed by the sweetgum's "gum balls" scattered on the ground, prickly and destabilizing underfoot. (Update: A friend says he collects them in winter to use for starting fires in the wood stove.)

Overabundance, too, can turn affection into surfeit. In the piedmont, stretching from central New Jersey down through North Carolina, sweetgum sprouts like a weed in areas we seek to maintain as meadows. Managing remnant piedmont prairies at Penny's Bend in Durham, NC, required mowing or prescribed burns to keep the rampant growth of sweetgum seedlings from smothering rare wildflowers. Grasslands in NJ often require similar intervention.

At least near water, one natural check on sweetgum's rampancy is beavers, who apparently love them for their inner bark laden with sweet gum--the liquid amber found in its latin name, Liquidambar styraciflua. This photo was taken during a walk at Plainsboro Preserve ten years ago. The beavers' preference was so strong, and the sweetgums so numerous, that we saw no other species of tree being chewed upon.

The vexing ubiquity in early succession that I've encountered in the eastern piedmont contrasts strikingly with my experience with sweetgum years prior in Ann Arbor, MI. Being a more southern species, the tree's native range doesn't extend into Michigan, so it's no surprise that a horticultural colleague at the University of Michigan proudly planted a sweetgum as something rare and wonderful, with its fall color and craggy winged stems. 

The sweetgum's wood, too, generates conflicting impressions. It rots quickly if left on the ground, is hard to split, and proves insubstantial as firewood. 

And yet, fifty years ago, my family moved into a beautiful house in Ann Arbor that was paneled in the most appealing way with sweetgum. The wood had a rich, warm glow--clearly a winner for paneling, but I have not knowingly encountered it since.

Then in 2023, we discovered a piece of wood from a packing crate bearing the name Demarest and Co on a wall inside the Veblen House. While researching the Demarest name, I came across an article about American Gumwood. In 1926, the Bureau of the Hardwood Manufacturer's Institute in Memphis, TN was promoting its new booklet: Beautiful American Gumwood: A superb native hardwood for interior woodwork and furniture.  

It took awhile to figure out that they were talking about sweetgum, not another eastern native called black gum. As a friend pointed out, calling sweetgum "gumwood" also risks confusion with the eucalyptus native to Australia, sometimes called gum tree.

The pamphlet begins by describing America's great forests as being our destiny to harvest. I've included long quotes to get a sense of the rhapsodic language.

The story of American gum wood dates back many centuries. Nature requires many years of favorable growth to produce a masterpiece, and in the vast stretches of our southland forests, extending from the Atlantic to the Mississippi valley and beyond, the quiet work of building cell and fibre was going on long before DeSoto and his valiant men first beheld in wonder the mighty "Father of Waters." What a marvel of creation, when from soil, moisture, and sunshine this fine wood came into being, now to be transformed by the hand of man into products that contribute to his well being and enjoyment.

By the mid-1920s, apparently, that enthusiastic harvest had led to more preferred species growing scarce:

Lumbermen have long known gumwood, yet vast tracts have been left standing while other interspersed hardwoods of widely varying species which happened to be wanted at the time, have been cut out. 

Overlooked in the past, sweetgum now stood ripe for the taking.

The tree itself, as it displays its lofty and graceful symmetry, is one of the glories of our native forests. Its sturdy proportions are enhanced by masses of scarlet, orange, and yellow leaves, which change, as the summer wanes. In size, it is heroic; one hundred feet to one hundred fifty feet in height, with a diameter of four or five feet, is not unusual. And some idea of the extent of growth of this important tree may be gained from the fact that with the exception of the oaks, gumwood exceeds all other hardwoods.

If sweetgums could read, they might have felt deeply flattered, but also be wondering if their tombstones were being readied and inscribed. And yet, one cannot be fully dismissive towards tree harvest--we who live in wooden houses and keep ourselves warm through the winter with fossil fuels rather than renewable energy from wood. 

This photo in the pamphlet looks reminiscent of the warm glow of the paneling I experienced fifty years ago, but doesn't capture the complexity and variety of mysteriously generated grains that sweetgum is capable of.

As the pamphlet explains:

Now no wood has more wonderfully interesting patterns than figured gumwood, but it is one of Nature's riddles to account for them. The pattern is not produced in the usual manner by quarter-sawing, although this process will improve any figure if it is already there. All one can say is that some trees have pronounced figured wood, others varying degrees of pattern, and many which show but slight indications of it. Undoubtedly the condition of the soil and the location of the individual tree affect in some mysterious way the structure of the wood. Only when the tree is felled, does the grain show itself as plain or figured. That is what makes the gumwood tree so interesting; it is like finding a }ewel, the value of which depends upon hidden qualities brought out by cutting and polishing.

The quizzled, tangled grain that makes sweetgum hard to split can bedazzle when milled. As with fall leaf color, the sweetgum's grain will vary tree to tree.

The figure ramifies through the wood at random, obeying no known laws. Gumwood logs will each display differing patterns, some subdued, some intricate and ornate.

Go forth, then, dear readers, and if you happen upon a sweetgum along a trail at Herrontown Woods or elsewhere in Princeton, slowly reaching for the dimensions the pamphlet describes, know that you are gazing upon a mystery of creation, whose creative chemistry is not yet fully understood, and whose sometimes plain, sometimes profound grain is impossible to predict from one tree to another.

There's one more passage in the pamphlet that helped me understand why my family home in Ann Arbor was paneled with sweetgum. The 1926 pamphlet may have influenced the couple, Walter and Martha Colby, who built the house in 1933, but they may also have encountered the paneling during their many travels in Europe. The pamphlet explains:

Europe has long recognized the exquisite beauty and texture of American gumwood. In fact, England, France, Italy, Spain, and other countries were first to recognize its fine working qualities. In America, however, its light was for a time hid under a bushel, so far as public acquaintance with its true worth is concerned. But now, due to growing appreciation of its merit, the valuable products of the gumwood tree stand forth proudly as "American gumwood,'* nothing else -so named, and so prized. The old adage, "a prophet is not without honor, save in his own country," no longer applies, if we may adjust this metaphor to a tree.

Here's a career move that musicians know well--a wood that needed to cultivate an audience abroad before it could be valued at home.