Hackberries are native to Alabama, where I grew up, but I was a child born of the piney woods, and I don’t recall ever noticing a single hackberry in my youth. The trees also grow in South Carolina, where I went to graduate school, but they didn’t register with me there, either. I was a newly transplanted Tennessean before I learned about “trash trees,” as people here call them.
The common hackberry is widespread from New England across to the Dakotas and down through the Midwest and Upper South. The Southern hackberry, a species also known as the sugarberry, blankets the Southeast down through Florida and west into Texas and northeastern Mexico. The two species overlap — and sometimes self-hybridize — in Tennessee. The Nashville naturalist Joanna Brichetto, author of the new book “This Is How a Robin Drinks: Essays on Urban Nature,” calls Nashville “the hackberry capital of the world.”
I don’t know if people call them trash trees in other places, but hackberries are widely disdained in the hackberry capital of the world. Their bark is a rough swath of warts. Their pocked, wrinkled, gall-infested leaves always look a little sick. In spring, their flowers drop to the ground and cover the sidewalks, and in fall their berrylike drupes do the same, without any gorgeous fall color to compensate for the mess.
One of the hackberries’ least desirable characteristics is not, strictly speaking, a feature of the trees themselves. Hackberries are targeted by the invasive Asian woolly hackberry aphid, which like all aphids excretes a sticky form of waste called honeydew. In wet summers, rain washes the honeydew away, but in dry years, the honeydew can accumulate and promote the growth of a soot-colored mold on whatever — car, sidewalk, patio furniture — happens to lie beneath the branches of a hackberry tree. “The mold is absolutely harmless,” Ms. Brichetto said when I asked her about it, “but people freak out.”
Unluckiest of all for a tree trying to survive the built human environment, hackberries have a growing habit that also freaks people out. Hackberries can grow giant horizontal branches that sprawl out across great expanses. Left unpruned, those heavy old limbs sometimes drop onto houses during storms.
By now you’re thinking, “Yeah, that’s totally a trash tree.” I spent my first years here thinking the same thing.
But then, one fall, I started noticing something about those drupes and those gnarly, pitiful-looking leaves: They were feeding a vast array of my wild neighbors at a time when everybody desperately needs to eat. The locals need to fatten up for the cold winter ahead. The migrators need to fatten up for their long journey.
The hackberry is the host plant for dozens of lepidoptera species: 49 here in Middle Tennessee, according to Ms. Brichetto. Butterflies who use hackberries as a nursery include the tawny emperor, the question mark, the mourning cloak and, of course, the beautiful hackberry emperor. It’s impossible not to love a hackberry emperor butterfly. These gentle creatures will land on your skin to partake of the salt and other minerals in your sweat. The behavior is called puddling, and many butterfly species can be found puddling in the mud. Hackberry emperors will puddle right on your hand.
Combine all the juicy caterpillars dining on hackberry leaves and all the tiny, protein-packed bugs inhabiting the galls and all the fruit the hackberry itself produces, and it becomes clear that a hackberry tree is a banquet set with something for everybody. Including us.
Well, not me. Our young, bird-planted hackberry grows in the wildest part of our yard where any drupes that fall to the ground are quickly consumed by all manner of mammals, reptiles and birds, but Ms. Brichetto loves to eat hackberry drupes. In “This Is How a Robin Drinks,” she describes them as “sweet but subtle. Think fruit leather, buttery, deep, though the flesh is no thicker than construction paper.”
Every year, the timing of nature’s bounty astounds me. Besides the hackberry drupes and the insects buzzing in my pollinator garden, just in our small yard alone there are also cedar and dogwood drupes, acorns and passionfruit, maple and redbud and magnolia seeds, arrowwood berries and pokeberries and beautyberries, coneflowers and black-eyed Susans and sunflowers and zinnias gone to seed. In the vast majority of my neighbors’ yards, the only plants feeding our wild neighbors are the hackberry trees.
But the bounty of that one tree is a munificence that many people, perhaps most of us, never notice. Taking place high in the boughs, the hackberry lays out its banquet just as the fall migration is reaching its peak.
We all hear the wild geese crying as they fly, and likewise the ducks and the sandhill cranes, but songbirds migrate primarily at night, lighting in trees and thickets to rest and feed during the day. Want to know who’s flying high above you as you sleep? Follow along on BirdCast, an astonishing prediction and counting tool that tells you how many birds passed overhead while you slept, how many are likely to pass that night, how many are passing in real time and which specific birds are in the area.
In a place that welcomes hackberry trees, birds will find those vital drupes. Because I knew that Ms. Brichetto is the animating force behind an Instagram account called the Hackberry Appreciation Society and is working on a book with the same title, I called her up to ask about what a hackberry offers migrating birds.
She was almost breathless with enthusiasm: “First, I want to say how nutritious those droops are. They’ve got protein and fat and carbohydrates and calcium and magnesium and vitamins.” Meanwhile, she pointed out, those leaf galls that make hackberry leaves so pimply-looking in summer are in fall hatching out tiny insects called psyllids that perfectly fit the tiny beaks of migrating warblers, who survive mainly on insects.
For us, though, the tree’s greatest benefit may be those great, reaching limbs. Hackberries are fast growing, drought tolerant and happy in even seemingly inhospitable settings. Best of all, they sequester carbon, mitigate storm runoff and provide a lovely shade that will cool us just as the planet is growing intolerably hot.
I include this note about the human benefits of hackberries because I know that otherwise my pleas to preserve these wondrous trees will certainly fail to move homeowners and landscapers and city planners alike. Already, when old houses fall to developers in the hackberry capital of the world, the first thing the builders do is cut down all the hackberry trees.
The post These ‘Trash Trees’ Are Actually a Banquet for Wildlife appeared first on New York Times.
