Treepedia Author to Speak at Veblen House--Sept. 24

Come this Friday, Sept. 24 at 6pm, for a free event next to Veblen House in Princeton. Author Joan Maloof is coming to Herrontown Woods to discuss her new book, Treepedia: A Brief Compendium of Arboreal Lore. The book has 100 short but stimulating profiles of extraordinary trees, forests, and the people working to protect them. 

The event will take place on the wooded grounds of Veblen House. The Friends of Herrontown Woods is hosting the event, which is sponsored by the Princeton Environmental Film Festival.

We're looking forward to meeting Joan and hearing about her book!

More information here.

A useful sampling of the book can be found here. 

Buy locally at a competitive price.

Labyrinth Books will be on hand at the event with copies of the book as well.

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

A Bee Tree in Herrontown Woods

 On April 12, I received an email from Jenny Ludmer saying she'd found a bee tree in Herrontown Woods. Jenny does a lot of good work locally at Sustainable Princeton, and she and her daughter have also helped out at our Princeton Botanical Art Garden, creating an educational display of wildlife bones on the rootball of an upturned tree. A bee tree, she explained, is a tree in which honeybees have a nest. This one is in 

an old tree just a few paces from the Green trail (about halfway from the Red and Yellow trails). The entrance to the honey bee nest is about 40 feet up in the tree and facing away from the trail.

She felt it safe to disclose the location, since it's so high up. My ambivalence about disclosing the location came from a post I had written last year around this time about having witnessed a swarm of honeybees in that same area of the preserve. I was told that the day after I posted, someone wearing a bee suit had come to Herrontown Woods and made off with the swarm! That was not exactly my intention.

With Jenny's email came some great photos showing bees already active in the nest. I'll quote extensively from her email, and then add a few things I've learned since.

I first discovered that honey bees live in trees about a year ago when I spotted a swarm in that very spot. Knowing that swarms never travel too far from the hive, I wondered how it got to the middle of Herrontown Woods. After reading several of Thomas Seeley's books and taking a class from Michael Thiele of Apis Arborea, I learned that not only do honey bees live in forest trees, they thrive in them. 

Yes, across the country, honey bees are suffering. Mites and numerous other calamities plague honey bees and make beekeeping a costly and depressing endeavor. Wild honey bees, on the other hand, are doing things just as nature intended. Instead of living low to the ground in thin-walled hive boxes, wild honey bees are nestled high in big trees, surrounded by thick trunk walls which protect them from temperature extremes. Unlike in traditional smooth hive boxes, honey bees cover the rough interior of the tree cavity with propolis, a sticky anti-fungal and antibacterial substance which helps create a healthier microenvironment for the bees. Furthermore, while traditional beekeepers maximize the size of their hives in an effort to harvest extreme amounts of honey, wild honey bees actively limit the size of their nest to about 40 liters and swarm frequently to spawn new generations and help prevent any large infestations of mites. Perhaps more importantly, no beekeeper decides the genetic line of these wild bees and there's no moving them around the country as farmers see fit. Nature and evolution ensure that the healthiest bees thrive precisely in the location where they were born.

So while traditional beekeepers claim the only way to keep honey bees alive is to medicate and artificially feed them, nature has a different story to tell. I hope all beekeepers get to learn from Thomas Seeley and Michael Thiele. 

Jenny's email led me to learn more about what honeybees experience in the early spring. In her photo here of the nest opening, you can see a bee exiting. The red flowers in the photo are red maple, whose flowers--early and abundant--are an important source of sustenance for bees.

Through a beautiful description of early spring activity in a bee hive, I quickly gained an appreciation for how risky early spring is for honeybees, and how important early sources of nectar are as the bees use their last winter stores to up the temperature of the hive, raise new young, and take "cleansing flights" as the weather warms. Even when flowers like maple are available, stormy spring weather may keep the bees from foraging.

That got me taking a closer look at early flowers, like this pussy willow in the Herrontown Woods botanical garden. Didn't see any honeybees, but this fly looked different from your usual fly. 

There's a progression of native spring ephemerals in the forest, beginning around the first week of April. This bloodroot is being visited by a bee, likely a native bee. (Honeybees were introduced from Europe in colonial times.)

In some areas we still have patches of wood anemone, 

and the spicebush are numerous, though their flowers last only a few days.

Hepaticas are very rarely seen. 

The far more numerous spring beauties would be worth taking a close look at for visits from honeybees.

One of Jenny's photos is of a honeybee taking a drink amidst the leaf litter on the forest floor. 

Here is a description of one of Thomas Seeley's books. Thanks to Jenny for letting us know about one of Herrontown Woods' hidden denizens.

Honeybee Democracy--a book

Honeybees make decisions collectively — and democratically. Every year, faced with the life-or-death problem of choosing and traveling to a new home, honeybees stake everything on a process that includes collective fact-finding, vigorous debate, and consensus building. In fact, as world-renowned animal behaviorist Thomas Seeley reveals, these incredible insects have much to teach us when it comes to collective wisdom and effective decision making. 

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.

The Hidden Life of Trees, and Other Deeply Flawed Books on Nature

There are some very misleading books, articles and opeds out there, claiming to give you the inside scoop on what nature is really like. Nature is very complex, involves a long learning curve to gain some understanding, and thus many readers prove vulnerable to cherry-picked evidence used to promote skewed points of view. 

Over the years, I've reviewed many of these false characterizations of nature, posted on another website and at Amazon and Goodreads, and reached out to some of the authors and editors. I'd like to think that I've played a role in diminishing the prevalence of one strand of skewed thinking: invasive species denial. I encountered it first in opinion pieces in the NY Times, then came across misleading books like The Rambunctious Garden, Beyond the War On Invasive Species, The New Wild, and Inheritors of the Earth. I also critiqued and reached out to the radio show, You Bet Your Garden, which was pretending that invasive species aren't a problem. 

Interestingly, one strand of invasive species denial springs from a blanket condemnation of pesticides, much as climate change denial is often motivated by a distaste for government. If the solution is objectionable, then deny the problem. Now, I don't like herbicides--Rodale's Organic Gardening Encyclopedia was my bible back when my interest in plants centered around growing food--but their targeted use is critical when dealing with invasive species on any meaningful scale. What works on an organic farm is not fully transferable to a nature preserve. There is an understandable desire for purity in our sullied world. Consider, though, the pragmatism with which we view western medicine and our own bodies. Just because antibiotics are abused by the meat industry doesn't mean we vilify all antibiotics everywhere, or refuse to take them if needed.

One book that's highly misleading is The Hidden Life of Trees, by Peter Wohlleben. Though it doesn't fit in the category of invasive species denial, it does use similar techniques to manipulate readers. It seems like a gentle book, but has an underlying logic that is not so pretty, as described here in a small excerpt from my review:

A book will garner more interest if it has an applecart to spill and an "Other" to dislike. In this case, the applecart is antiquated views of trees, and the "Others" to look down upon are narrow-minded scientists and commercial foresters. Another common ingredient is to let the reader off the hook by suggesting we as individuals need expend no energy to compensate for all the ways human activity has thrown nature out of balance.

Nearly all of these books are written by non-scientists and reviewed by non-scientists, leaving the public unprotected from any misinformation the books may carry.

Though invasive species denial seems to be fading, Wohlleben's book remains very popular. Many of these books get very high ratings on Amazon and elsewhere. Though the Amazon review section for a book is a useful place to break people's bubbles, I've noticed that the reviews that Amazon labels as "top critical review" are neither the strongest nor the most informative and recommended negative reviews on the site. Here's an example, in which the most highly recommended negative review is buried below others. 

(Update: As of January, 2025, Amazon lists only positive reviews under "Top Reviews". By scrolling down through the positive reviews and clicking on "read more reviews", a "Top positive review" and "Top critical review" appear side by side. It's good to see that, at least in this case, the "Top critical review" is also the critical review readers found most helpful.)

2020 has definitively demonstrated just how hard it is for truth to compete. In politics, a preponderance of the misinformation is being generated and consumed by the rightwing, but it's instructive to witness how those who care deeply about nature can also prove vulnerable to false narratives.

Becoming a Tree

A tree was spotted taking a selfie of its shadow with the Veblen House.

Yes, you can become a tree when the angle of the sun is right, and wave to the flowers growing below, and cast your mighty shadow across the expanse, to mingle with the land's many memories of the passing day.

Resurrecting the Butternut Tree

Of all the many silhouettes that trees cast against the winter sky, one that gives me particular pleasure is that of the butternut. Most people haven't heard of this tree, also called white walnut or the scientific Juglans cinerea, which was laid low by an imported canker disease beginning in the 1990s. The few surviving specimens in our area often lack the classic vertical ambitions of a tree, tending to grow in a gangly, everywhichway manner while other kinds of trees launch a bold ascent towards the sun. The less than graceful shape is for me still heroic, given the tree's battle with disease. The nut--oblong as opposed to the black walnut's round shape--is said to be very tasty, dense with oil and protein.

A couple resident Princetonians with deep tree knowledge made me aware of the tree's presence in town. One was Bill Sachs, a Princeton grad and editor of the Northern Nut Growers Association newsletter. He had been doing consulting for the Textile Research Institute on the east side of town when he noticed a couple native butternuts growing on their property. Given how few butternuts remain in Princeton, it was a significant find.

It takes cross-fertilization between two trees to make nuts, and one fall I helped him collect those two trees' offerings of about 50 nuts, which he carefully planted in pots and nurtured into young trees about a foot high. Those seedlings took on even greater significance when the two parent trees were lost--one to wind, the other to a saw when it got in the way, ironically enough, of an environmental remediation on the property.

If not for Bill's seedlings, the only thing left of butternuts in Princeton in coming years might have been a street sign at Princeton Community Village.

It was not necessarily easy to find a good place to plant the young trees. Butternuts won't grow in the shade, and most of our open space is heavily shaded by taller-growing trees the butternut can't compete with. In one of our early efforts, I served as assistant as Bill planted a few trees on the edge of a clearing near Veblen House in Herrontown Woods.

Elsewhere in town, some may have mourned the loss of a spruce/pine forest to hurricane winds at Mountain Lakes, but when the town cleared away the debris, Bill and I found ourselves with a clean slate into which to plant native species underrepresented in our dense preserved forests.

Bill carefully caged the trees to protect them from the deer.

My caged structures, as in the story of The Three Little Pigs, were less tall and sturdy, with deer sometimes getting the chance to play the role of a toothful wolf, setting the seedlings back until I reinforced the cages.

Some will say it's best to plant butternuts far from existing mature butternuts that might have the canker, but in a few spots, we took the approach of planting two young ones near a handful of mature butternuts still to be found in the wild. Arborist Bob Wells pointed us to two old loners up near Herrontown Woods, one growing at the edge of Stone Hill Church, and one in Autumn Hill Reservation.

With the blessing of the facilities manager at Stone Hill Church, it was relatively easy to find sunny spots on the church grounds,

but our efforts to plant two young trees next to the lone butternut in Autumn Hill turned into a real adventure. The only sunny spot available near the existing mature tree was a thicket of invasive shrubs and vines. Kurt Tazelaar and I hewed an opening in the rampant growth, discovering in the process the remains of a long abandoned farmstead from the early 20th century. It may well be that the butternut was part of the original farmstead, and had survived long enough to serve as a marker of sorts, leading us back to a bit of lost Princeton history.

Bill had found another lone native butternut in a valley at Mountain Lakes, and I found an opening nearby where we planted a couple more saplings. The older butternut was blown down soon thereafter, dashing our hopes that the new and old could cross pollinate, but the two young ones are now 20 feet tall,

and are being well taken care of by Mountain Lakes staff and volunteers.

Butternuts have a lot going against them. They are unable to compete against taller growing trees, which means a laissez-faire approach to nature would cause them to be shaded out. They are short-lived, which along with the imported disease may be why most of the remaining mature trees we knew of in town have been lost over the past decade.

They don't seem to be faring any better elsewhere. Bob Wells tells me that "Morris Arboretum had two Juglans cinerea up until Nov. 1 when the wind that night blew one lead of tree #1 into the second one totally destroying butternut #2! Now only one misshaped specimen left." The finest specimen he knows in central NJ is in Hightstown, which he describes as "20” DBH and 40-45 feet tall, somewhat scrappy looking but great for a white walnut."

We can be thankful that through Bill's initiative and caring, and assistance from Bob and others, a new generation has a chance in Princeton. Additional robust young trees now grow at TRI and at Harrison Street Park, where my friend Clifford played a role. With some followup care, sunlight, time and luck, the butternut's curious form and the highly touted taste may endure, and we'll get a chance to finally taste one.

Shade Trees and a Cool Streets Contest

It's time to shine light on shade. If Princeton held a contest for the coolest, best shaded blocks, I'd nominate a couple blocks in my neighborhood. One is at the corner of Erdman Avenue and Tee-Ar Place, where four giant pin oaks, healthy despite the local prevalence of bacterial leaf scorch, extend their broad limbs southward and westward over the pavement.

Another is on Stanley Avenue, where some more healthy pin oaks are doing the job. On the left is a Norway Maple--not my favorite species, but in this case well placed to shade the pavement.

Having a contest would shine light, so to speak, on the importance of being strategic about where trees are planted. Some homeowners may understandably want to have sunlight reach a garden, or solar panels on the roof. Neither of these need conflict with optimizing shade where it is most important--over pavement, where the sun's light energy would otherwise be turned into heat when it hits blacktop, contributing to the urban heat-island effect.

9/11 Memorial Plantings

Stymied from reaching our intended destination of the Brooklyn Botanical Garden by various closed subways on a Sunday afternoon, we found ourselves close by the World Trade Center site, and decided to take a look. The footprints of the twin towers have each been turned into chasms where curtains of water fall from one depth down into a still deeper abyss. The symbolism is powerful--ascension transformed into endless descent. The curtains of water, played with by the wind, can sometimes appear to be pulling apart, as if something were about to be revealed, but the moment passes and the water returns to a uniform downward motion.

There is so much to grieve there, the lives lost on the site and on that day--their names etched into the frame of metal--and all the lives lost in distant lands due to the nation's skewed response in the years that followed. There is so much that I wish I could pull back up from the darkness at the center of the sunken pools.

But this post was to be about the plantings we saw, which were hundreds of swamp white oaks planted in rows. Swamp white oaks can be found occasionally planted along Princeton's streets, and growing naturally in low-lying forests. Strange that a species found naturally in water-logged lowlands would grow well in the dry, compacted soils of city streets, but the tree is adapted to the low oxygen levels that both soils share. Some of the 9/11 trees came from a NJ nursery that specializes in memorial plantings.

Water used to sustain the trees comes from underground cisterns that capture runoff.

Nearby is St. Paul's Cathedral, which improbably survived the crash of the towers. The cemetery behind the church is filled with headstones grown faceless with time.

Along the fringe of the cemetery grows a pure stand of what looks like a native sedge (on the right in the photo)--the sort that gets only a foot or so high and can form expansive, parklike sedge meadows in local woodlands.

NY City now grows many other unexpected echoes of native habitats, the most recent discovery being Brooklyn Bridge Park, where one of the trails runs along a beautifully maintained stream habitat packed with native species.

But that joy of diversity might be out of place at the 9/11 memorial and St. Paul's Cathedral, where the monocultures of swamp white oak and sedge seem intended instead to reinforce a uniform response of grief.

Hicans and Other Useful Trees at Princeton Battlefield

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

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

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

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

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

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

Chinese chestnuts, too, are having a banner year.

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

It, too, is laden with chestnuts.

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

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

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

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

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

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

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