A writer unravels New Haven’s tree history as she investigates the strange affliction spreading across her trees back home.
“Biophilia, if it exists, and I believe it exists, is the innately emotional affiliation of human beings to other living organisms.” — E.O. Wilson
The road into my neighborhood in Jupiter, Florida belongs on a magazine cover. Dozens of healthy southern oaks line each side of the road. The trees have tangled branches that form an arch over the asphalt. In the shade, I can look up at the canopy and see patches of clear sky through the leaves. Next to cookie-cutter houses, there are lakes home to great blue herons, ibises, and roseate spoonbills. It feels like I live in a nature preserve rather than in a neighborhood of artificial golf courses and manicured palm trees.
Though beautiful, my neighborhood trees are frail. Raised at the same nursery and planted at equal distances apart,every tree is almost identical. But a forest is strongest when it is diverse. When one oak tree falls, the others may fall with it.
A few years ago, I noticed fingerprint-shaped black marks had appeared on a tree in front of my house. Each day, the marks grew into circles: seven, nine, then thirteen circular markings where bark bulged black. Something inside was trying to break free, as if the tree were giving birth to death.
Within a year, the circles had spread until they were no longer separately defined. A reddish brown color tinged the dark bark. Then, the dark circles appeared on the tree next door. The leaves still looked healthy. They still turned slightly brighter shades in the spring and dropped acorns in the fall.
A Google search could not explain what was causing the tree stress. Perhaps it was sickness. Perhaps it was the stress of aging in a cramped space. I frantically emailed the Homeowners Association (HOA) president. Three years later, I am still waiting for a response.
I had to leave the oak trees when I moved to New Haven for college, but I couldn’t stop thinking about them. Wanting to help my own oaks and learn more about human connection to landscaped and urban trees, I reached out to Susanna Keriö, who researches tree stress at the Connecticut Agricultural Experiment Station.
When Keriö was a child, a large rotten tree fell over in a city park in her hometown in Finland. It landed on a group of young friends, crushing one of them. As a forest pathologist, she cannot help noticing the symptoms of stress— signs of disease and management defects on every landscaped tree she passes— wondering which is in danger of dying or falling next.
Through talking to her, I learned that centuries before my oak trees started getting sick, New Haven had a massive tree epidemic of its own.
· · · · ·
In 1686, two juvenile elm trees were planted on what is now Elm Street. For seven decades, these trees were left with no companions but each other. Seventythree years later, New Haven planted a row of 250 sycamore and elm trees around the town green.
In the late eighteenth century, the “Great Planting” occurred, when a US senator, James Hillhouse, planted hundreds of elms from Temple to GroveStreet. By this time the trees took over New Haven, and the town became known as “Elm City.” It was said to be the most beautiful town in New England.
Urban tree landscaping was integral to New Haven, one of America’s first planned cities. City planners assigned each tree a space. Confined to a grid, the trees had no choice but to fight for room in the canopy. And as they grew, their roots spread over the gridlines and cracked the sidewalks.
James Hillhouse and New Haven residents were not prepared to care for their elms. They assumed that the trees could take care of themselves.
By 1883, the neglect spiraled: bites from horses, burns from electric lines, and poison from gas lines meant only a few elms had bark left unscathed. At the city’s plea, Yale forestry graduate George Alexander Crombie led the removal of 5,000 sick trees and the planting of 10,000 new ones.
That was in 1921. Twenty-five years later, the trees faced risk beyond mere neglect.
In 1936, the elm bark beetle from the Netherlands infected American Elms with a fungus known as Dutch Elm Disease. The trees all suffered together. The beetles burrowed through their bark, leaving forklike patterns in their wake. As the trees died, Elm City risked losing its nickname.
The New Haven Green had become a graveyard for dying trees. Eventually, the city removed elm corpses and planted ash trees in their place.
I did not want my oak trees to die the same collective death.
· · · · ·
On a rainy day in 2025, Keriö and I trudged from her lab to a rotting ash tree stump. Judging by the number of rings the stump had, it seemed at least fifty years old. Keriö pointed at a carved-out band, one centimeter wide, wrapping around the base of the tree. It was the tunneled wake of the emerald ash borer, a fluorescent green beetle that came to Connecticut a decade ago. At least one hundred million ash trees have died because of this beetle, Keriö said.
In December, I returned to Florida and saw that the affliction of my oaks had spread. A row of over thirty trees had bark turned black. One oak was entirely consumed by the darkness from its base to its topmost branches.
On an afternoon walk, I noticed a gap in the tree canopy over my neighborhood. The blue sky pierced through a large hole that a tree once covered. My parents told me that while I was gone, a moderate hurricane ripped through our town. The wind took with it a couple of roof shingles and a twenty-five-year-old tree. Within minutes of the first gust, the tree crashed down onto the asphalt. The stump stood severed from its body.
Within a week of the tree’s fall, the HOA removed the stump and planted a new young oak. I saw the puny, threefeet-tall oak amidst its mature peers.Would the pathogen, fungus, whatever it was, attack the baby tree?
Felicia Millett, Keriö’s colleague, often receives diseased tree samples. A plant and tree diagnostician, Millett analyzes twigs, leaves, and bark to identify sick plants. I thought she might be able to solve my tree mystery.
In her early career, Millett was a sky scraper rope access technician, but after moving out of New York City, she turned to climbing trees. After getting an arborist license, she pruned branches and removed sick specimens, chainsaw in hand.
She told me with a roll of her eyes that arborists are much more likely to have to remove trees than to care for them. After eight years of being a “green Grim Reaper,” Millett wanted to use her knowledge to help sick trees, not just remove them. She put down her chainsaw and went back to school.
When I showed Keriö and Millett the pictures of my trees, they were both perplexed. Neither of them have any experience with Floridian climate and wondered if the discoloration was just a result of the intense humidity of the area. They wondered: is it caused by climate change? or a physical fungus? a gall? a deep cut? Both experts noted that just seeing a picture of a faraway tree does not offer the whole story.
Online experts did not help either. A University of Florida agriculture extension local chapter has left my most recent voicemails unanswered. Tree forums and stack exchanges gave me contradictory answers. And I was ghosted on identical posts I made on Facebook and Reddit.
I refuse to believe that the oak tree feet from my front door is patient zero. That my neighborhood is home to the first recorded outbreak. Someone must have a diagnosis, a prognosis, a medicine for my trees.
The possibility remains that these black splotches are harmless to the trees. Maybe the trees are going through puberty, and the fingerprints are just pimples rather than a pox. Perhaps my hours of research and conversations did nothing. I can’t save my trees if they do not even need saving. But what if they do?
I am worried that the fate of New Haven’s ash and elm will repeat in my town. I am worried that the live oak will be stolen from me. I am worried that the black splotches will grow into mighty hands that will rip down my canopy. My trees will not live forever, but I want them to at least outlive me. So before the trees fall, I’ll keep searching for answers. ∎
