For several years I have admired one tree whenever I drive down Logan Street in Louisville’s East Smoketown neighborhood. The lonely sycamore is growing on the rooftop of a vacant 13-story building known as the Merchants Ice & Cold Storage. The tree, perched on the edge of the rooftop, has survived hot and dry summers and the extraordinary flash freeze on Christmas Eve, 2022, when temperatures fell 50 degrees in 12 hours, to -5 F.

The sycamore fills me with wonder.

Tracey Williams, proprietress of  Greensleeves Design, was just the person I needed to talk to. I had mentioned the remarkable rooftop sycamore to others who did not rise to the idea of the 13th floor with the same excitement I had. Tracey is a Kentucky professional gardener and designer with a fertile imagination.

Rooftop sycamore last fall

Tracey Williams rose to the occasion

She has had years of experience designing and installing gardens, green roofs, vertical walls, and rooftop gardens.

We met one sunny Friday morning in the parking lot of the abandoned Merchants Ice Tower, besides the adjacent brewery complex that once produced 75,000 barrels of beer a year, in the late 19th century. The National Prohibition Act put the skids on alcohol in early 1920. The focus shifted to cold storage. The 13-story, two million-square-foot, reinforced concrete colossus, promoted as the largest ice-storage building in the south, was opened in early 1921 and closed in 1998.

Tracey and I looked up toward the tiny speck of a tree on the rooftop.

Rooftop sycamore this spring

The sycamore is close to ten years old, I am guessing. Trespassing graffiti taggers and their friends once walked up the stairs for rooftop parties. Gusty winds may have blown fluffy sycamore seed to the rooftop. Or it’s possible a goldfinch, chickadee, or sparrow fed on the disintegrating buttonball seed pods in late winter and defecated a few seeds on the rooftop.

Merchants Ice & Cold Storage is now fenced and surveilled.

It is impossible to see from the parking lot, or from drone photos, whether there is a roof-top depression that holds a small reservoir of water for the tree’s survival. There is precious little nutrition beyond the tree absorbing the decay of its own leaf litter. Yet the sycamore defiantly expresses a will to live.

My nephew, Robbie Cooper, was flying out of Louisville two days ago and caught a phone photo of the Ice Tower, and the sycamore.  Can you see a little green speck on the rooftop?

I think of the remarkable sycamore as acknowledgement of a local renaissance. Smoketown and the nearby neighborhood around Shelby Park—one of Louisville’s 17 Olmsted-designed parks—have blossomed in the last ten years.

Artists make good gardeners

While I was focused on the rooftop sycamore, Tracey Williams pointed to other spontaneous trees growing on brick buildings of the complex. Perhaps kissing cousins— the catalpa or the princess tree.

She soon began colorfully reframing the Ice Tower. The artist was riffing with ideas. She saw birds nesting in pockets along the side of the building. Tracey imagined a drone dispersing seeds, coated with a hydrogel, that would stick to the walls. She embellished her fantasy with sedums, portulacas, and mosses. The dreamy possibilities seemed endless. Tracey imagined Kentucky natives like crossvine (Bignonia capreolata)—a hummingbird favorite—and the Kentucky Wisteria macrostachya cascading down the brick walls from the roof top. I suggested Forsythia suspensa. And if a sycamore can grow on a roof, Japanese roof iris (Iris tectorum) and native prickly pear cactus (Opuntia humilis) might stand a chance. Our excitement was growing.

Forsythia suspensa near Big Rock in Louisville’s Cherokee Park

Iris tectorum, Sun Jiao/Wikimedia Commons photo.

Prickly pear with Hyacinth ‘Blue Pearl’. Salvisa, Kentucky.

Tracey and I talked again a few weeks later. She had decided there was a simpler way. “Let the birds and bees pollinate the building’s habitat.”

During the U.S. perennial boom that launched in the late 1980s, Ed Snodgrass  and I broke free from weedless lawns and a boring suburban plan palate. We kept growing. Ed was always a furlong ahead of me. He emailed recently and said, “Will we see the oak leaf full of holes as the potential beauty of the butterfly even if we never see the butterfly?”

I like a clean border, and am skilled with a Dutch hoe.

But I am bordering now on a ragged edge with appreciation for the spontaneity, beauty and benefit of dandelions and butterweeds Packera (Senecio) glabella.

Butterweed and abandoned house in Salvisa, Kentucky last month

John Little has been an influence on this notion of layering aesthetics with biodiversity. He and Ed like to share thoughts. They are seasoned green roof consultants and, more important, they share a vision of ecological optimization.

How do you optimize the Ice Tower into a unit of local ecology on land and roof?

Nature will take its course with or without human interference.

A little help doesn’t hurt

Take the example of Canvey Wick in Essex, England. The 93-hectare (230 acre) property was originally a grazing marshland along the Thames that was prepared as a site for an oil refinery in the 1970s. Pockets of soil were raised with dredged sediment from the river. Today the “brownfield oasis is a mosaic of flower rich grassland” with 3,200 species of invertebrates, birds, and plants.

Ed explained how the popular High Line in New York City was only reimagined after decision makers realized they could not afford to tear down the 90-year-old built-to-last trestle.

“The Merchants Ice Tower is a beautifully imposing building, so proportionally solid somehow,” Tracey Williams said.

Iconic also

Love Jones spoofed their image on the side of the Ice Tower. Other local icons, Muhammad Ali and Jennifer Lawrence, have banners hanging in Louisville. Love Jones was tired of waiting for theirs. It did not go well.

Photos courtesy of Love Jones

Rewilding the Merchants Ice Tower as a monolithic birdhouse appeals to me. It’s fun to envision walls speckled with lichen, moss, and ebony spleenwort on the east and north sides; and Sedum pulchellum poking out of sunny wall pockets nourished by bird droppings.

The annual widows-cross, Sedum pulchellum, Salvisa, Kentucky.

Crevice gardens have become popular among rock gardeners. Graffiti is old school. Guerilla gardeners might mix soil into a do-it-yourself, semi-shaded pile of brick or concrete rubble. Then sow seeds of the native annual, Miami mist (Phacelia purshii). Don’t miss the commotion of small bees drawn to sweet nectar.

Miami mist in early May in Salvisa, Kentucky.

Trellis Brewing, next door, was a surprise as well. While pioneering on a forsaken urban site, they have revitalized Smoketown’s brewing past with respect to the historic integrity of the complex and have allowed a few beautiful weeds to sneak in along the edges.

Sweet clover at Trellis Brewing

Cow thistle at Trellis Brewing

As I was leaving, it was hard to miss a honking male Canadian goose standing guard on the rooftop of Trellis Brewing.

I hope wind and the gander seed bomb the Ice Tower and barren grounds with serendipity.