Chimney Swifts Converge on a Tower Near You

Updated 5.18: The back side of an abandoned school building doesn't seem an auspicious place to spot endangered wildlife, but check out that chimney. It changes everything.

In a recent letter to Town Topics, Princeton ecology professor Andy Dobson invited readers to witness one of nature's more remarkable annual phenomena, playing out in and above the tower of the old Valley Road School. From his letter:

In the half hour after sunset, several hundred swifts will be “turning and turning in a narrowing gyre” centered around the tower of old Valley Road School building behind Conte’s Pizza. It is quite a spectacular sight as the rapidly spinning circle of birds “know exactly where it leads, and you can watch them go ‘round and ‘round each time.” Suddenly, they will begin to drop down and disappear into the tower to roost for the night. “Wait ‘til you see half the things that haven’t happened yet.”

Andy encourages us to "come to the playing field on Valley Road and enjoy a truly remarkable local wildlife spectacle." 

"They will probably be there at dusk for the next couple of weeks while they pair up and locate nest sites on local tall buildings. The site is Princeton’s equivalent of the Serengeti wildebeest crossing the Mara River on their annual great migration."

His letter was published on May 8, and in typical fashion I didn't get myself over there to have a look until 9 days later. When I arrived, right at sundown, there was nothing to be seen--a golden opportunity for self-rebuke--but just as I began to leave, a high-pitched cheeping somewhere above pulled me back. They came, a few at first, then many, swooping down on the chimney only to veer away at the last possible moment. There is no clear choreography to their acrobatic flight, as they head off in all directions at great speed, sometimes in pairs but mostly on their own, each one's acrobatic flight describing a broad circle out across fields and rooftops, always to return to play yet again with the magnetic pull of the chimney. As the light fades, their gleeful independence ultimately yields to the collective impulse, drawing them down into the chimney's depths to spend the night.

   

Here's a link to Andy's wonderful letter. And here is a link to local writer Carolyn Jones' well researched article on our local chimney swifts and the longterm threat redevelopment of the Valley Road School site poses to their very specialized habitat. 

Andy's comparison of chimney swifts to the migration of the wildebeests that he studies in Africa has added meaning for those of us who have seen the university as often detached from the community of which it is a part. He recently began teaching a course called "Woods and Rivers of Princeton." The course gets students out exploring local nature, and has become so popular that this coming fall's course is triply over-subscribed. This valuing of the local is gratifying to see, and I like to think is part of a larger trend. 

Update, 5.31.24 Andy reports that "the swifts are still there, numbers declining as they pair up and locate nest sites. They should be back by the middle of August in even larger numbers with young of the year."

Encountering Old (Plant) Friends at Fairchild Tropical Botanical Garden

Among the many surprising encounters we had during a visit to the Fairchild Tropical Botanical Garden--during a holiday spent in Coconut Grove, more than a year ago now--was the opportunity to sit down and have a chat with the celebrated writer and conservationist Marjory Stoneman Douglas. She's aging well. After a brief bout with death in 1998, by which time she had reached the age of 108, she still looks to be going strong 25 years later. Sitting alone on a bench, she looked like she wanted company, perhaps to tell me about her seminal book, The Everglades: River of Grass, and how she helped found the Fairchild Gardens.

Walking the paved trails that wind through 83 acres, I felt suffused with a bloom of happiness. Maybe I was empathizing with all the happy plants. In Princeton, things can be bleak in winter, but even in summer there is evidence everywhere of trees dying back due to introduced insects and diseases. This patch of Florida is by comparison exuberantly florid. 

Or maybe it was the endearing mix of impeccable and casual, which perhaps reflects the Garden's varied founders, who range from an accountant/businessman to a worldwide explorer to environmental advocates like Douglas. The grounds are at once formal and informal. Paved trails have imprints of leaves and fruits. Encountering no clear route from the parking lot to the visitors' center, we ducked through a shrub border. The lawns are manicured, and yet the plant labels are low-key, well-aged and aging well. 

Structures range from  a sophisticated greenhouse hosting tropical plants and myriad butterflies to this authentic-looking thatched roof pavilion. 

Along the winding paths, there were old friends, like this thriving ombu. Lacking true wood, it is really an overgrown forb masquerading as a tree. I first encountered it in Argentina, where stories tell of it giving shelter to gauchos out on the pampas. Its latin name, Phytolacca dioica, shows it to be in the same genus as our pokeweed. If you saw it blooming, as I did once in a park in the Recoleta neighborhood of Buenos Aires, you might think you're looking at a pokeweed 50 feet high.

How often do we get to see a baobab tree, and a massive one at that? 

Witnessing this assemblage of plants from around the world stirred all sorts of memories of past travels. This tree reminded me of a hike up into the hills outside Medellin, Columbia, in 1974, where a patchwork of hand-cultivated onion fields gave way to small hilltop forests of tree ferns and hummingbirds. 

Petrified wood triggered memories of visiting a petrified forest during a long drive through Argentine Patagonia.

And this swollen trunk brought the name "palo borracho" to mind, a name that translates to "drunken stick", in reference to the bottle-shape of the trunk. They are common along the streets of Buenos Aires. I think this one is Ceibe speciosa, the silk floss tree, closely related to the kapok tree.

The Garden's 83 acres were donated by an accountant and businessman named Robert Montgomery, who counted among his friends the globetrotting plant collector David Fairchild, who lived next door and supplied many of the plants. The garden's website describes how Fairchild "visited every continent in the world (except Antarctica) and brought back hundreds of important plants, including mangos, alfalfa, nectarines, dates, cotton, soybeans, bamboos and the flowering cherry trees that grace Washington D.C." 

The National Tropical Botanical Garden goes even farther in describing Fairchild's legacy: 

"Avocado, mango, kale, quinoa, dates, hops, pistachios, nectarines, pomegranates, myriad citrus, Egyptian cotton, soybeans, and bamboo are just a few of the thousands, if not hundreds of thousands of plants Fairchild introduced to the United States."

The desire to import plants that could prove useful for food, fiber, and other uses dates at least back to George Washington and Thomas Jefferson, but gained intensity during the golden age of travel--the late 19th century when Fairchild began his career. Plants were considered so important to the economy and security of the nation that the U.S. Botanic Garden--a particular passion of George Washington's--was placed next door to the Capitol building. That's it down in the lower left of this map. 

To 21st or even 20th century eyes, the proximity of a botanical garden to the nation's center of legislative power feels odd in the extreme. Plants are more likely now to be viewed as quaint decoration to soften the edges of our hardened world. When I visited the U.S. Botanic Garden, probably in the 1990s, the conservatory looked a bit down in the mouth, largely serving as a refuge for the homeless. More respect for George Washington's dream has been shown since then. 

Those must have been heady times, early in the 20th century, when Fairchild oversaw the import of more than 100,000 species of plants from around the world. Their utility and beauty promised to enrich our country by diversifying our farms, gardens and kitchens. Few, including Fairchild, wanted to think about the downside, as some of these imports escaped gardens and ran wild over the landscape, displacing native species. A botanical enrichment has contributed over time to an ecological degradation. 

I looked into whether David Fairchild ever came to terms with the potential for introduced species to run amok, and plan to write about it in a separate post. He was aware that some nonnatives like kudzu and lebbek were spreading aggressively, but there is no verifiable evidence as yet that he sounded a warning. 

It's heartening to see that the Fairchild Tropical Botanical Garden itself has evolved to take the threat of invasive species very seriously. According to multiple sources, it monitors closely its collection of exotic plants and takes action to prevent spread beyond the Garden's borders. I want very much to believe all this is true and will continue to be true, the better to enjoy the memory of my visit there, encountering so many old (plant) friends from my earlier travels around the world. 

The Lost Forest of Rogers Refuge

This past November, I received a request to look at a lost forest in Princeton. 

The request came from what may be the oldest open space organization in town--the Friends of Rogers Refuge. Dating back to 1967, FORR has been working with the town, and the water company that owns the land just down from the Institute Woods, to sustain the refuge's role as premier habitat for a tremendous diversity of birds.

Over the years, I've been able to witness and collaborate with a progression of leaders who have overseen stewardship--the Southerlands, Tom Poole, the Spars, the Varians, and most recently David Padulo. 

At annual meetings, discussions have tended to focus on the refuge's central feature, the surprisingly extensive marsh--how to keep it wet enough and protect it from the super-aggressive Phragmitis.

But this year, concern now extends to the floodplain woodlands surrounding the marsh--also vital bird habitat. One of these woodlands, thriving four years ago, has lost its trees.

This was not a forest classically lost to logging. The trees were not cut down but rather strangled over the course of several years, then left standing, each tree a monument to its past life. 

Few have seen the now ubiquitous strangler, the Emerald Ash Borer accidentally introduced to the U.S. from Asia. It's larvae work quietly under cover of bark, feasting on the ash trees' circulatory tissues. 

That a whole forest could die speaks to how common ash trees once were. The most numerous tree in Princeton up until just a few years ago, comprising more than 10% of the tree cover, the ash tree's skeletons can be found throughout the canopy of residential and open space lands. Ash were particularly good at colonizing abandoned fields, to the point of dominating one area of what is now Rogers Refuge. 

As the botanist in an organization of birders, I was asked what the longterm prognosis for this lost forest might be. Winnie Spar, Joe Melton, and I walked the red trail to have a look.

One striking feature is what I call "poison ivy trees." These are dead trees, still standing, that have been scaled by poison ivy vines, with their classic "hairy is scary" stems. In order to bloom, poison ivy must climb a tree, sending out lateral flowering shoots along the way. The branch-like laterals give the tree the look of still being alive, even though all the leaves are now poison ivy. The flowers produce berries that, birders will enthusiastically tell you, serve as important food for birds.

Another feature of a lost forest is the shrub growth that now thrives on the infusion of sunlight previously claimed by the tree canopy. Much of this shrub growth, unfortunately, is nonnative and inedible to wildlife, like this Asian Photinia. At least it can be said that the invasive shrubs are not as thick at Rogers Refuge as they are at the Institute Woods just up the hill.

A few other native tree species fill a small portion of the void. In early November, the occasional silver maple and pin oak still had many of their leaves. Mixed in were a couple elms, and a red maple. 

Used to the numerous red maples at Herrontown Woods on the other side of town, I was surprised to find instead an abundance of box elder of every size growing in this broad floodplain of the Refuge. Related to maples, box elder are not the most statuesque of trees, but their soft wood can make good bird habitat. They now stand as the main hope for rebound in this patch of former forest. 

The walk being with such knowledgeable birders, attention never strayed far from bird life. We saw a couple pileated woodpeckers, a coopers hawk and a couple other larger hawks. Winnie kept up a running monologue about the status of this or that bird. Mockingbirds have been around for a long time, but the catbirds keep them out of their territories when they are present. While a warming climate is causing many birds to extend their ranges northward, ravens, surprisingly, are moving south. She's seen some in the Refuge. Warblers love something about the spicebush flowers, whether it's the flowers themselves or an insect in them. Blue gray knatcatchers were mentioned, along with many other bird names that didn't register in my botanical brain.

There's a lot of concern that last year's fires in Canada have been very hard on migrating birds that nest up there. A woman who catches and tags migrant birds had been having very few birds coming back down from Canada, but her catch/tag/release activity, conducted on Sundays, was hampered by rains every weekend this fall. One day she got only ten birds, total. 

But then Winnie is quick to add that she saw Cape May Warblers in the Refuge for the first time, several in fact, with immatures, and they too nest in Canada. Winnie is one to accent the positive, while acknowledging that migrant bird numbers are down 50-90%. 

This lost forest, the decline in bird numbers, accelerating changes in climate, democracy under threat--in many ways, America is losing its memory of what it once was. The soil, for its part, holds memory through the seeds that remain dormant within it. Back when the seed bank--this stockpile of seeds yet to sprout--was dominated by the seeds of native species, succession as an ecological phenomenon featured an orderly and predictable progression of species, from grassland to shrubland to mature forest. But the soil under our feet has lost its memory, whether by plow, development, intense browsing, or displacement of native species. Invasive lesser celandine, poisonous to wildlife, coats the ground in the spring, followed by inedible stiltgrass and its billions of seeds in late summer. Invasive shrubs and deer combine to limit native species and thwart the once timeless process of succession. Though the tree canopy is still dominated by natives, these are under increasing attack from introduced insects and disease.

Even healthy trees can be overwhelmed by vines of porcelainberry and wisteria.

Given the circumstances, it's fair to ask what sense there is in persevering. What I find is that the native growth force, if often smothered and badly abused, remains intact. When given a chance to prosper, native plants and wildlife still can thrive. In Rogers Refuge, we've seen a tremendous rebound of spicebush since the town began culling deer to reduce browsing pressure. That in turn has improved habitat for birds. FORR has paid contractors to successfully set back the Phragmitis and porcelainberry. 

Through periodic interventions over a number of years, the Varians have virtually eliminated the one patch of invasive Japanese knotweed at Rogers Refuge. 

We pick our spots, time our interventions strategically to have the most impact for the least amount of effort, and look for opportunities. Despite the tragedy of losing ash trees, the new openings in the canopy could potentially allow native shrubs to grow, flower and bear in ways they haven't since being shaded out decades ago. 

Our inherited environmental mindset is that nature, if protected from intentional depredations like logging and draining, will heal itself. As FORR's webmaster Laurie Larson points out, "when Charles H. Rogers and the Southerlands started birding the “Water Company” in the 60s and 70s it was a landfill." The initial fight was to put an end to dumping. But now, at Rogers Refuge and many other places, the main depredations (invasive species, climate change) are unintentional, and the healing must be helped along by intentional effort. That effort could seem a sacrifice, but the primary feeling is one of gratitude, for the chance to work with nature--the greatest and most generously creative collaborator of all. 

Fountain Park--Ancestral Connection to an Eternal Spring

It is my sister-in-law Edna, not my siblings and I, who has taken particular satisfaction in researching our family's ancestry. She traced one lineage on my father's side back to Lord Hempleman of Hesse-Kassel. If my parents had known there was a Lord in our family's past, they might have called on me to show more regal bearing as a kid. Though it's flattering to learn of some royal ancestry, the most exciting find was another lineage, on my mother's side, extending seven generations back to an eternal spring located one hundred miles west of Princeton. 

In Schaefferstown, Pennsylvania, there is a fountain that flows nonstop, year-round, without aid of any pump. It's water rises from a spring perched on the hillside, then flows down the hill to a fountain where residents of the town still come to have a drink.

The fountain was part of an innovative underground system of wooden pipes that transported water from the spring down one side of a valley and up the other to provide drinking water in wooden troughs on the town square. 

According to some literature:

"The water company in Schaefferstown has the oldest gravitational conveyance system by underground pipes in the United States. The water system was constructed sometime between 1744 and 1750 by the founder of the town, Alexander Schaeffer."

It's also called "the oldest Chartered Waterworks still in operation in the United States."

This ancestral connection has all sorts of resonance in my life. Water holds an attraction for most people, but in my life it has been a recurring theme. I grew up near beautiful Lake Geneva, WI, got a masters degree in water quality, founded a watershed association, turned a soggy field in a public park into a wetland garden, dug a series of miniponds in my backyard, and favor wildflowers that thrive in wet soil. As a kid walking home from school when winter was finally giving way to spring, I loved to build dams out of wet snow to hold back the snowmelt along the curb. Clearly, all this time Alexander Schaeffer's genes have been whispering encouragement to his great-great-great-great-great grandson.

The eternal spring is in a park that also feels eternal, appropriately called Fountain Park, 

Halfway up the hillside is the spring house, which looks more like a mound of earth, with a wall on the bottom end, its own picket fence

and its own caretaker--one in a long line of caretakers dating back to the mid-1700s

Peer in through the door in the wall, 

and you'll find what looks like a small indoor swimming pool--a durably crafted stone chamber where the water collects before flowing down to the fountain. 

One enduring mystery, which I'm hoping a hydrogeologist who strays upon this post can explain, is why springs tend to emerge not at the bottom of a hill but halfway down. 

Climb up this hill and you quickly reach the top, where there hardly seems to be enough land to feed such a copious and consistent spring--not much more than a small farm field, with the land beyond lower and flowing off in different directions. 

German immigrant Alexander Schaeffer laid out the town in a way reminiscent of those he knew in Europe, and initially called it Heidelberg, after one of the most beautiful cities in Germany. 

Water from the spring still feeds troughs along Market Street, bringing back memories of ancient Roman water works seen in Italy.

The park is owned and maintained by residents of Market Street. Buy a house on Market Street, and you also become part owner and steward of the park. 

While in town, I met one of the owner/stewards, Ann Ginder, who gave me some copies of this pamphlet. At the time--my visit was in 2018--her husband, Andy, was president of the group of residents along the street who take care of Fountain Park. Carl "Cork" Meyer, who I didn't meet, is the one who does most of the physical work to maintain the park. 

On the town square, Alexander Schaeffer built what still stands as a tavern called Franklin House, and it was there that I met what proved to be a distant cousin of mine, Howard Kramer. Our ancestral connection to each other and the town's founder can be tracked back via gravestones variously populated with names like Meyer, Moyer, and Meier. Ann Ginder calls Howard the "unofficial mayor" of Schaefferstown.

Schaeffer's house and farm on the outskirts of town are being restored as a historic site, with summer festivals to celebrate the town's history. It's not just the unique drinking water system and a long line of advocates and stewards that has saved the town's historical features. As one website explains,

"Because the area was left isolated from rail lines, canals, and modern highways, the town did not grow appreciably in the 19th or 20th centuries. This greatly influenced the small-town look and feel that the area maintains today."

Thanks to my sister-in-law Edna for discovering our ancestral link to this special place, founded by my great-great-great-great-great grandfather. And thanks to those who care enough to cherish and sustain that history. Howard wrote to me that "years ago there was a steady line of people getting their drinking water here and at the fountain mid-way up Market St." Even now, with all the world's turbulence, radical change, and myriad threats to what we once thought of as forever, there is an improbable spring perched above a Pennsylvania valley where the water still flows.

Nash Park in West Windsor Needs a Loving Heart

There's a curious park that I stumbled upon in West Windsor called Nash Park, named in honor of the Nobel Prize-winning mathematician, John Nash, and his wife Alicia. They were longtime residents of West Windsor before being tragically killed in an auto accident in 2015. 

When you walk around this expanse of mostly grass, you may get the feeling that something is missing. What is it? Stewardship? Practicality? Trees?

In reading articles generated in 2017 soon after the park was introduced to the world, I've been able to piece together the original intent. I had been calling it "John Nash Park," but the more powerful story very much includes Alicia. 

As the Town Topics described it in 2017, "Mr. Nash, a senior research mathematician in the Princeton University mathematics department and winner of the 1994 Nobel Prize for economics for his work in game theory, suffered from paranoid schizophrenia and was the subject of the Academy Award-winning 2002 film, A Beautiful Mind. Mrs. Nash, a mental health advocate, was credited with saving Mr. Nash’s life during his prolonged illness."

The West Windsor mayor at the time, Shing-Fu Hsueh, saw the park as a means of showing appreciation for all that John Nash contributed to mankind. He said that John Nash's story demonstrates how “Even though you have problems, you can be recognized around the world.” 

In a Community News article, township landscape architect Daniel Dobrimilsky described the initial concept, “a town green with gardens along the edges. We decided to make the space in the middle the size of a regulation croquet lawn, about a 100 feet by a 100 feet." Croquet! Now I know that I am not the only person in the universe who has long harbored a sentimental affection for croquet.

Dobrimilsky also talked about the desire to improve social life. “One of the concepts we came up with was a community garden, since it is a nice way to share traditions and understand each other better. So I came up with the idea of having an Asian-themed garden, because we had a growing Asian population, and most of the landscapes in the area really followed traditional European designs." An interview with the mayor describes him as one of the first Asians to be elected to public office in the U.S. Shing-Fu Hsueh left his position as a water quality engineer at the DEP soon after  beginning what would be a 16 year stint as mayor of West Windsor, from 2002 to 2018.

Now, six years after those articles and five years after Hsueh's departure, I see no croquet, nor any gardens beyond a shrub or two. A Grounds for Sculpture-like statue of the Nashes walking through the park side by side, for which $190,000 would have needed to be raised, has not materialized. (Update: As of 2023, a less costly version is still being pursued.)

But a number of features have sprouted on this flat square of land that otherwise has no features of its own. The Lions Club installed this welcoming sculpture.

A donated pavilion stands in the back, with a couple benches facing away from the park.

The most interesting view from the benches is up into the pagoda structure above. A plaque explains that a similar pavilion was built in Mount Emei, China, where Nash once gave a lecture. 

An eagle scout project is another landmark, adding a zig and a zag to the path that circles the park, crossing over what could be imagined to be a sandy streambed. 

And then there's this linear feature, with benches at either end as if for spectators to watch some unknown sort of sports event. 

Nothing is explained, beyond a plaque that describes the park as "A beautiful place for a beautiful mind and a loving heart," a sentiment borrowed from Sylvia Nasar's biography of Nash, "A Beautiful Mind."

Picnic tables, this one painted with a faded chessboard, sit out in the field, unshaded by trees. 

The few trees, like this golden rain tree, are planted far from the seating, and look stunted.

Take a close look at the base of the trunk and you'll see why the trees aren't growing much. Evidently, the maintenance crew, in its efforts to kill weeds around the trees, has girdled the trunks with its weed whippers. 

Some tree trunks also have badly damaged trunks, whether from rubbing by deer or sun scorch. 

The park appears well positioned between business and residential neighborhoods, and maintenance crews are keeping the park neat and clean--in a kind of holding pattern. But the needs of both plants and people seem to be getting left out of the equation. As a mathematician might say, those are key variables that must be included in any equation for success. The picnic tables are unshaded. The benches in the pavilion aren't oriented to encourage socializing. There's no place for kids to play and explore. Is there a clear place to park, and a water source for anyone wishing to nurture new plantings? 

The park clearly had an inspired beginning, but now it needs someone who loves plants and loves people, and who can create spaces within it where people will naturally want to gather, and enjoy each other and the landscape around them. Like the troubled genius John Nash himself, Nash Park needs a loving heart.

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.