Update on Native Butternuts and Chestnuts in Princeton

There's a lot of gratitude being expressed towards trees these days. The gratitude tends to be towards trees in general, but this fall, I'm especially grateful for three trees in particular. 

All three, growing at the TRI property, are among many that have been planted over the years by local nut tree expert Bill Sachs and me as part of an effort to bring back two marginalized native tree species. One is an American chestnut. The other two are butternuts. Both of these species have been laid low by introduced diseases, and I feel fortunate to be part of an effort to make them numerous once again in Princeton. 

The two butternuts at TRI bore a bumper crop this year, some 200 nuts--the first sizable harvest since the parents to these two trees were lost 14 years ago. One fell in a storm; the other ironically was cut down as part of an environmental remediation. It's Bill who played the role of Noah, growing new seedlings from the seeds we collected from the two trees before they were lost.

We planted other members of this new generation of locally sourced native butternut trees at Harrison Street Park, Herrontown Woods, Mountain Lakes, and Stone Hill Church. Bill in particular did a lot of the followup work, checking the cages that protected them from the deer, and serving as a one man bucket brigade to sustain the trees through droughts in their first couple years.

Bill also did a great deal of work to re-establish native chestnut trees in Princeton. That project began in 2010, when chestnut researcher Sandra Anagnostakis, of the Connecticut Agricultural Experiment Station came to town to give a talk. She brought along 20 chestnut seedlings for us to plant in local parks. The seedlings were 15/16th native, 1/16th Japanese chestnut. Of all of those that Bill planted, at the Princeton Battlefield, TRI, Herrontown Woods, and Harrison Street Park, only the one tree at TRI has borne fruit. Many of the hybrid trees have died, despite the effort to breed in resistance. 

There have been some other efforts to get the American chestnut growing again in Princeton, by the Friends of Princeton Open Space at Mountain Lakes and also by arborist Bob Wells at Greenway Meadows. The best bet for repopulating our world with the American chestnut may well lie in research that led to inserting a gene from wheat into the American chestnut genome that confers resistance. This seems a much more dependable and faster way to embed resistance to the fungus, and bring back this spectacularly useful native tree. 

In the meantime, we can celebrate the hard-won harvest we're getting from this new generation of native nut trees, and after letting them cure a bit will even get to find out what a butternut tastes like.

Related posts

From 2021: Butternut Redux--A New Generation Bears its First Crop

From 2010: The American Chestnut Returns to Princeton

Harrison Street Park: Contrasting Tales of Trees and Wildflowers

Most people drive by Harrison Street Park unawares. It's an old neighborhood park that lacks parking, and so mostly serves those who live close enough to walk there. Whenever I think to stop by this surprisingly spacious park close to Nassau Street, it's to check in on dreams living and remembered. 

One dream is bringing back the American chestnut. We've planted a number of chestnuts around town that are 15/16th native. They were originally crossed with a resistant asian chestnut, then backcrossed with the aim of ending up with a predominantly native chestnut tree that still carries the Asian species' resistance to chestnut blight. Some of these trees have proven susceptible to the blight, but two in particular have resisted the blight thus far. One of these is in Harrison Street Park, nearly 20 feet tall now. 

We also planted two native butternuts there, another native tree that has been marginalized by an introduced disease. It's good to see them thriving and starting to bear nuts. 

There's also an attempt by the town, successful thus far, to keep a grove of ash trees protected from the introduced Emerald Ash Borer, via systemic applications of insecticide. Another small grove of trees was planted through a citizen donation and collaboration with the Shade Tree Commission.

Other dreams for Harrison Street Park, involving wildflower plantings, have not done so well. Princeton Borough had great dreams for this park at one time. In 2006, they hired me to conduct an ecological assessment and write a stewardship plan. Then they hired a landscape architecture firm from Philadelphia to design improvements to the park. Neighbors offered many ideas and expressed many opinions. The old wading pool--a relic from a distant, more sustainable era when kids gathered in their neighborhood parks in the summer--was removed, the play equipment was updated, and a few new features were installed. 

Some $30,000 was spent on new native plantings that looked good for a year or two before going into steady decline. The idea was that neighbors would care for all these new plants. Of course, a drought promptly ensued. Some of the neighbors rose to the occasion to keep the plants going, but the extensive flower beds required more than an initial season of zeal. Neither the borough maintenance crews nor any of the neighbors had the training or interest to keep the flower beds weeded over the longterm. 

This flower bed is now a massive stand of Canada thistle and mugwort. 

The plant with the big leaves is a common weed in the midwest that is showing up more and more in Princeton. It looks like rhubarb, but is in fact burdock. 

There's a swale in the park that receives runoff from a private parking lot next door. These wet, sunny spots can tip the balance towards native species. A friend and I planted various floodplain species--joe pye weed, tall meadowrue, etc--but also planted Jerusalem artichoke, which is a native sunflower species with edible tubers. 

When planting an aggressive plant like a native sunflower, it's easy to believe one will follow up and keep its expansionist growth in check. That's almost never the case. The sunflowers has spread aggressively underground over the years, and have long since swallowed the other wildflowers in their dense growth. Each year the sunflower clone expands, as park crews mow around its fringe. 

We also planted a couple pawpaw trees there, but they were overwhelmed by the sunflowers. A couple black walnut trees sprouted on their own and had much better luck, somehow managing to rise above the sunflowers. Trees that plant themselves tend to be more successful than trees planted by people. On the upside, the sunflowers are so aggressive that they require no weeding, and there's a dazzling display of yellow in the fall. But, like some of the other plantings at Harrison St Park over the years, it's not what was originally envisioned. 

Some Flowering Trees and Shrubs in Mid-May

A whole lot of white, and a little red right now. Here's fringe tree

and pagoda dogwood

Red buckeye is a small tree that makes a big show here and there on residential streets. I've only seen it growing wild along a back road in the North Carolina coastal plain.

pawpaw hanging promisingly

This fragrant snowbell (Styrax obassia), was planted by Bob Wells behind Veblen House in Herrontown Woods.

And across the street from me, a horse chestnut puts on a dazzling display, with flowering, towering black locusts adding lofty blooms behind.

Wisteria Contained

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

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

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

Related posts:

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

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

Wisteria's Tamed and Wild Twinings

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

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

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

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

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

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

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

A couple related posts:

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

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

The Emerald Ash Borer Quietly Changes Princeton's Skyline

Scan any skyline in Princeton and you're likely to see dieback in the trees. This happens to be the view from the front step of Veblen House in Herrontown Woods, but the same can be seen in the woods surrounding Princeton Battlefield, and most everywhere else in town. 

We're losing thousands of trees in Princeton, some quickly, some slowly. As described in past writings on this blog, dating back to 2010, the Emerald Ash Borer is proving every bit as destructive as predicted, killing all species of ash tree. And many red and pin oaks are succumbing to an introduced disease called bacterial leaf scorch. 

Many of the trees lost to introduced insects and pathogens in the past century or so--first the American chestnut, then the American elm, and now the ashes--had been dominant trees in our forests. Until the Emerald Ash Borer arrived, sweeping east from its point of introduction (hitchhiking in packing crates from Asia) in southeastern Michigan, the ash had been Princeton's most common tree. The physical gaps, if not the ecological ones, get filled by one thing or another. At Herrontown Woods, tulip trees, red maples, hickories, and sweetgums grow into the voids. 

These radical changes in the forest canopy present challenges for those of us who manage Princeton's woodlands. Dead ash trees become brittle over time. Branches and sometimes whole trees fall across trails, requiring removal. Though the town arborist and his crew have been helping, oftentimes it's volunteers who carry chainsaws deep into the preserves to reopen a trail. 

At Rogers Refuge, Princeton's birding mecca just downhill from the Institute Woods, it is avid birders who work on the trails. Lee and Melinda Varian have been particularly active. Melinda recently sent an email to the Friends of Rogers Refuge group, of which I'm a part, to report that "Lee and I just went out with our chainsaws for the third time this week to
clear fallen Ash trees from the Red Trail. It’s really heartbreaking."

She sent us these photos of a 50 year old ash tree that had fallen across a trail. Another volunteer at Rogers Refuge, Winifred Spar, wrote about how the history of the refuge is embedded in each tree's growth rings.  

In this section of trunk, where the bark has fallen away, you can see how the Emerald Ash Borer larvae consume the tree's cambium. Like the earth's total dependence on a thin surrounding layer of atmosphere (which of course our machines' invisible emissions are radically altering), a tree's vascular system depends on a thin layer of tissue surrounding the trunk, just below the bark. Lacking any evolved defense against the introduced ash borers, the native ash trees quickly become girdled and die. 

Though other tree species like oak and elm may be considered more statuesque, I have been surprised on occasion by just how gloriously big an ash can become. Two examples stood along the oval drive leading to George Washington's home at Mount Vernon. Another stood at the top of the bank of the Delaware in Lambertville. I was in awe at the thickness of their trunks. Surely the one in Lambertville has been lost, but might those at Mt. Vernon have been saved through chemical injections?

As tens of thousands of ash trees die in Princeton, requiring a vast expenditure to remove, has anyone actually seen an Emerald Ash Borer? I have seen a grand total of one, and that was a decade ago in Ann Arbor, MI, close to where they first were discovered in the U.S. By contrast, everyone has seen, and squashed, a Spotted Lanternfly, yet compare the harm done by the these two introduced insects and it's clear the largely unseen ash borer has been far more devastating in its impact. Our senses largely fail us for discerning the greatest threats to our world, be they an elusive insect or, far more devastating still, too much carbon dioxide in the atmosphere. To coin a phrase, call it "quiet radicalism."

By allowing light to reach the understory, the gaps in the canopy created by so many dying trees present a mix of problems and opportunity for managing our preserves. What shrubs will take advantage of the extra solar power, previously harvested by the trees but now reaching the forest understory? Native understory species like blackhaw Viburnum, highbush blueberry, and spicebush can now flourish and produce more fruit. If the deer didn't eat them, rarer native species like shadbush, pinxter azalea, and hearts 'a bustin' could make a comeback. But oftentimes, it is nonnative invasive shrubs that have colonized our woodlands--Photinia, honeysuckle, linden viburnum, winged euonymus, multiflora rose, and privet. Left uneaten by wildlife, the nonnative shrubs have a competitive advantage that could render our woodlands clogged with foliage inedible for local herbivores. 

Changes in the understory can affect whether wildlife thrive. Winifred, a keen observer of bird life in Princeton, wonders "if the gaps in the canopy and increased invasive understory may already be having an effect on birds in the Institute Woods. It might explain why there were noticeably fewer Ovenbirds this past summer; they are ground nesters." 

The ash tree won't disappear altogether. One old post, from 2014, entitled After Emerald Ash Borer, What Will Princeton Look Like, describes a visit to Ann Arbor, where the ash borer had already swept through. We still found young ash trees. My best guess back then remains my best guess now:

I would speculate that, once the native and introduced parasitic wasps become widespread, they in combination with woodpeckers could allow ash trees to persist in Princeton, though perhaps few would grow to maturity unless regularly treated with systemic pesticide.

Carolyn Edelman, a poet and nature enthusiast, recently posted a quote of Adlai Stevenson, II, dating back to a speech he gave in 1952. Its sentiment is part of a vein of American thought that views love of the American landscape as deeply connected to the love of freedom. For me, it is not coincidence that we live in a time when both nature and democracy are being undermined.  Read the quote through today's filter of gender equality and inclusion to find its relevance.

It was always accounted a virtue in a man to love his country. With us it is now something more than a virtue. It is a necessity. When an American says that he loves his country, he means not only that he loves the New England hills, the prairies glistening in the sun, the wide and rising plains, the great mountains, and the sea. He means that he loves an inner air, an inner light in which freedom lives and in which a man can draw the breath of self-respect. Men who have offered their lives for their country know that patriotism is not the fear of something; it is the love of something.

A great tree species passes from the landscape, but the love remains, and in that love reside both grief and possibilities.

The Wet Meadows Project Turns 25

It was in southern Michigan that I first fell in love with prairie and savanna habitats, and so a favorite place to visit, when in Ann Arbor for a gig, is the Children's Wet Meadow Project in Buhr Park. There was a time when tall grass prairies extended into southern Michigan, with stately bur oaks sometimes rising above to create savannas. The persistent grass stems and oak leaves would invite what I call "mildfires" to sweep through, recycling nutrients and creating a clean slate for the next year's growth. And so some of these wet meadows are burned annually by professionals, while neighborhood families gather some distance back to enjoy this controlled, elegant horticultural show that speaks to a wild past. Kids then scatter wildflower seeds in the ashes.

The story of the wet meadows, now in their 25th year, grows out of the transformative relationship between one woman, Jeannine Palms, and the park that serendipitously stretched beyond her backyard.

I've written about it in other posts, about how her love of people, plants, and the local Mallett's Creek spurred a community initiative to turn turfgrass into native grassland. Since Jeannine ran a daycare for many years, this has very much been a kid-powered project, as can be seen during workdays and in the signs that explain how the meadows filter runoff headed for the creek.

A favorite prairie grass is little bluestem. It's always seemed like fall colors of prairie grasses are more vivid in the midwest. Perhaps a colder climate plays a role? The most brilliant example is Indian grass, whose bright orange and yellow mimic the flames that sometimes consume it.

Milkweed, anyone? Common milkweed spreads underground. A mildfire clears away the dead stems without harming the roots.

Dead stems can be as beautiful as the flowers. New England aster, wild bergamot, and the red leaves of blackberry mix with Indian grass.

After planting many wet meadows, the Wet Meadow Project began creating a food forest, to the right in this photo, with trees bearing apples, cherries and pawpaws, a grape arbor, raspberries, and many other edibles. 

Though a native meadow can be low-maintenance, it still requires ongoing vigilance to pull invasive species before they get established. A food forest, too, is only as good as the care it receives.

And sometimes that care involves using targeted treatment of weeds with herbicide. The food forest may well be organic, but a habitat is different from an organic farm. You can't till or mulch a prairie to control invasive plants. It's more like a body that may sometimes require medicine. In this case, low toxicity herbicide was applied to woody plants that, in a prairie, are considered weeds.

It looks like they made an exception for one very special tree--a native chestnut, which was planted in one of the meadows.

The local wildlife has a casual presence. What appeared to be a large green ant was crossing the asphalt path that winds through the park. It turns out to be variously named an oil beetle or blister beetle, Meloe campanicollis, though I must not have disturbed it enough to prompt it to secrete the oil that could blister my skin.

A hawk (red-tailed?) seemed unperturbed as we walked by.

Congratulations to Jeannine and all the other volunteers who have brought prairies back to life in Buhr Park.

Native Chestnuts in Princeton--the Next Generation

Many of us have lived our whole lives without seeing a mature native American chestnut tree. An excellent NY Times Magazine article described it as a true gift of nature, the perfect tree, growing straight and tall, with rot-resistant wood, and bearing nuts that were easily gathered and eaten, sustaining wildlife and people alike. My first encounter with the American chestnut was the sight of their fallen trunks in a Massachusetts forest, 70 years after the fungus that causes chestnut blight was discovered in NY city in 1904. The massive trunks I saw, lying on a slope in the shade of young white pine, were among the billions that the accidentally imported fungus would ultimately kill in the U.S. Since the roots survive the fungus, there was still a living community of underground chestnut trees beneath our feet in that Massachusetts forest. One of the roots had sent up a sprout about twenty feet tall--promising, one would like to think, but its slim trunk was already ringed by the fungus, its fate sealed before it could bear nuts. 

One of the projects I'm involved in is reintroducing native chestnuts to Princeton. The initiative began in 2009 with an email from Bill Sachs, a Princetonian with considerable expertise when it comes to nut-bearing trees. Bill reported that Sandra Anagnostakis, "one of (if not the) world’s leading experts on the pathology of American chestnut," had agreed to supply us with disease-resistant, hybrid American chestnut trees. Sandra's efforts to breed resistant native chestnuts at the Connecticut Agricultural Experiment Station over many decades was apparently unconnected to the American Chestnut Foundation. The trees were 15/16th native, and Bill with occasional help from me and others proceeded to plant them at the Princeton Battlefield, Harrison Street Park, the Textile Research Institute, Mountain Lakes and Herrontown Woods. 

Some fared better than others. Many, despite having been bred for resistance, nonetheless struggled with the blight that had laid the mighty tree low a century ago. This fall, however, paralleling our work to bring back native butternuts, one of the chestnut trees has borne fertile seeds.  

Bill made repeat visits to the tree to collect the nuts as they ripened. The deer likely got many, but he managed to gather quite a few, some of which he encouraged me to cold stratify. Stratification has always been an intimidating concept for me, suggesting sophisticated manipulation to get a seed to germinate, but in this case it turned out to be not much more than stuffing some seeds in a bag of moist peat moss and leaving it in the back of the refrigerator for awhile. 

The tree, hosted by TRI near Carnegie Lake in eastern Princeton, bore generously despite significant pruning by the periodical cicadas early in the growing season. 

This past summer a friend had sent me a photo of another chestnut tree that, being smaller, was much more affected by the cicadas' egg-laying activities. They cut into stems to lay their eggs, which ends up killing the foot or two of stem beyond where the eggs are deposited. 

We'll see how these various trees do over time, and if a second generation of these mostly native chestnuts comes into being. The NY Times article was mostly about efforts to develop a blight-resistant American chestnut through genetic modification. That thirty year project, with a geneticist named William Powell as the main protagonist, has been successful. They managed to find a gene in wheat that confers resistance when inserted into the chestnut's genome. 

Adding one gene would seem a much more precise and less intrusive means of correcting a century old wrong than adding many genes, most of which are irrelevant to improving resistance, from asian chestnuts. But don't expect these ever so slightly and efficiently modified native chestnuts to be available any time soon. There are strict regulatory hurdles that must be overcome. 

For me, the situation demonstrates two powerful forces in the human world. One is the fear of the slippery slope. Would an elegant genetic fix for the American chestnut open the doors to a wave of less admirable genetic modifications of our world? The other powerful force is our focus on regulating intentional change, while allowing unintentional change to run rampant. While the government spends years deliberating over one gene being added to the native chestnut tree, global trade is introducing an ongoing wave of new organisms to the country, any one of which could be the next emerald ash borer or spotted lanternfly. 

In the meantime, we'll be thankful for the mostly native chestnuts we have, and see what we can grow.

Below is more info I've taken from some of Bill Sachs' emails. Click on Read More. 

Chance Encounters with Trees in Lambertville and New Hope

My awareness of trees made me a mixed bag as a companion on a recent visit to Lambertville. The same eye that spots nature's wonders makes it hard to ignore tragedy.

My first find was a red mulberry tree, encountered on the Lambertville side of the bridge, draping itself over the canal. My daughter and I gorged on the berries.

Most mulberry trees grow straight up, leaving the abundant berries frustratingly out of reach, but this one grows right out of the old stone wall of the canal. Suspended above the water, its limbs grow horizontally towards the sidewalk, making for a beautiful presentation of berries to passersby.

The view down the Delaware River from the bridge was glorious, the air above the long-traveled water fresh and richly scented. It was a time to be positive, to focus on the upside, but I couldn't help scrutinizing that seemingly verdant distant hillside. 

There, mixed in with the green, was evidence of the massive dieoff of ash trees--a profound moment in history that we are living through, ever since the Emerald ash borer hitchhiked to America in the wood of packing crates twenty years ago. 

There are immense ash trees perched on the bluff overlooking the river, like the grove on the left here that shaded us as we began our leisurely walk across the bridge. They are still green enough to deceive most people, but will end up like those just to their right in the photo. These observations could have triggered thoughts of past dieoffs that transformed our forests, marginalizing once dominant trees like American chestnut and elm, but

fortunately, there was a more positive tree story to shift to. Walking across the bridge, I noticed an improbably large tree rising above the houses along the shore in New Hope that looked to be flourishing. Later, I ducked down an alley to have a closer look. A bicentennial plaque in front of it says it was alive at the time of the signing of the U.S. Constitution in 1787. That makes it more than 234 years old.

A man living next to it, who grew more friendly once he realized we were interested in the tree, said it's a willow oak. 

When I lived in North Carolina, we had many willow oak trees. Conveniently, their narrow leaves would settle in nicely with the pine needles, and after a few years I let that mix of leaves and needles replace the lawn as a pleasing surface for the yard. 

Some of the branches of this specimen would be impressive trees on their own.

New Hope prospered early on because of the ferry, and also because of the mills powered by the steady springfed waters of the resident stream. Tucked behind the Bucks County Playhouse, which used to be a mill, this dam frames a scenic, misty cove. A great blue heron stood stockstill, scrutinizing the falling waters, waiting for the stream to deliver dinner.

As if it were an old friend, I pointed out the native indigo bush lining the shore below the theater. I didn't get much of a response from my companions, but for me, knowing the plants makes it possible to feel familiarity even in a place where one knows no one at all, and makes an extraordinary place all the more extraordinary. 

Related reading from 2015: A Steamboat Named SPLASH: Riding the Real Deal on the Delaware River

Native Azaleas Bloom Again at Herrontown Woods

This spring, Herrontown Woods had its first big show of native azalea blooms in many decades. They were all on one bush, but it was a start. I counted the blossoms--25, which is 22 more than the grand total from five years ago. A friend who grew up in Princeton told me that wild azaleas had once been a common sight in spring. What caused them to disappear? The answer is more deer and more shade. 

The pinxter azaleas are not the only species that has languished in the deep shade of the forest. Shadbush and hearts-a-bustin' have also been marginalized. It took some years of exploration to realize that they were still there, surviving in a miniature state, a foot or two tall, deprived of sunlight, nibbled down by deer. 

One of the first to be spotted, during a morning walk five years back, was a spindly pinxter azalea that had somehow managed to grow three flowers, like a weak SOS signal coming from a distressed ship. When the shrub failed to bloom at all the following year, I responded by digging a small sideshoot from the base and planting it in the preserve's Botanical Art Garden, where we maintain the equivalent of a forest opening. Bathed in sunlight and protected from deer browse, the azalea has thrived in a way it never could beneath dense trees.

Growing next to the azalea in the botanical garden is a shadbush, so named because it blooms when the shad are migrating up rivers in early spring to spawn. It, too, is finally getting an opportunity to grow to maturity for the first time in decades. 

Another species seldom encountered along the Princeton Ridge--only two have been found in Herrontown Woods thus far--is the pagoda dogwood. It's alternate leaves (arising not in pairs but instead singly on alternating sides of the stem) give it another common name, alternate-leaved dogwood, and also its latin name, Cornus alternifolia. The flowers aren't that showy--pompom-like clusters reminiscent of the more common silky dogwood--but the pagoda-like shape of the branches is striking. Hopefully we'll be able to witness that as this one grows up in a sunnier location than is available among the dense trees of the woods.

Other size-disadvantaged woody species being brought into the botanical garden to get out of the shade and deer browse are hazelnut, persimmon, and hearts-a-bustin'.

A native chestnut tree is also checking out its new home in the botanical art garden. The chestnut has been disadvantaged in today's forested preserves not by limited size but by the lingering chestnut blight disease that nearly eliminated them from the continent a century ago. This one is 15/16th native, crossed with an asian species that hopefully conferred immunity. Unlike the other woody plants mentioned in this post, the planted chestnut is not a local genotype.

In the early days of the Herrontown Woods preserve, there was a chestnut tree still growing along the yellow trail. The blight doesn't affect the roots, so it essentially sent the species "underground." Chestnuts persisted to some extent by sending up suckers that would grow to ten or twenty feet before succumbing to the fungus, at which point yet another sucker would be generated, to meet the same fate. Eventually, I suppose, the roots ran out of energy to keep sending up suckers.

Butternut, too, has been laid low more by introduced disease than by size limitations, and will be getting a home in the botanical garden. 

Add to these woody species all the sun-loving wildflowers that have an even harder time surviving in our tree-dominated preserves, and it becomes clear that what we have created at Herrontown Woods is a place where disadvantaged native species can have a chance to show their stuff. This opportunity for upward mobility was once built into natural systems, back when megafauna and fire served to set back the trees, when deer were kept in check by predators, and long before invasive species stifled with their overwhelming growth. We love our trees. For many people, trees are a symbol of nature itself, and yet it's important to remember that the less lofty species are also part of nature, and have as much claim as large trees to a place in our preserves. Thus, "plant a tree", for all its resonance and popular appeal, is more relevant to our streets than our preserves when it comes to actions we can take to heal nature and nurture diversity.

Four additional native azaleas were added to the Botanical Art Garden last year, rescued from deep latency and finally given a chance to grow. In time, they could make for a really big show, and it all started with a floral SOS along a trail. 

Some Unusual Trees

 Here are some encounters with unusual trees in Princeton. 

In the Institute Woods, we saw a couple beech trees some distance from a trail and took a closer look. Not quite the California redwood that people could once drive a car through, but similar in concept. 

Another beech nearby was harder to pose with.

The view up the inside of the trunk.

Bark with this shaved appearance, seen recently in a deep forest in northeastern Princeton, is called "ash blonding," said to happen when woodpeckers go after the emerald ash borers inside the ash tree. Note the tell-tale "D"-shaped holes where the borers exit. 

More uplifting was this tall spruce, which during the holidays sports a shining star, which then gets replaced on the owner's March 17 birthday 

by an Irish clover. 

Here's an odd sighting. It looks like an ordinary stump, but the tree was clearly cut down and removed. The forest is quite old, so the logging must have been long ago. My guess is that it's the stump of a chestnut tree harvested a century ago. One of the many wonderful traits of the native chestnut, lost to an introduced disease a century ago, was its resistance to decay. Working briefly for a forester in Massachusetts in the 1970s, I saw whole logs of fallen chestnuts still intact despite the passage of many decades. I'm ready to be wrong on this ID, but that's what I'm going with for now.

A month ago, I stopped by the TRI property to check up on a couple native butternuts planted there by Bill Sachs. The two trees are flourishing except for some vines that I really need to get back there and cut. They were planted close to where Bill and I harvested about fifty nuts, perhaps the last native butternut harvest in town before the bounteous tree was blown down in a storm. Thanks to Bill, the harvest turned into many saplings that we've planted in many locations in town, including Harrison Street Park, Herrontown Woods, Mountain Lakes, Stone Hill Church, and TRI. The tree has a gangly growth form, but the nuts are said to be delicious. The tree needs our help because of an introduced disease that has laid it low. This one's look really healthy thus far.

Some other stories about unusual trees:

How lightning that struck one tree at Morven actually killed the adjacent tree instead.

An extraordinary giant white pine that may still grow near 206.