
Nikki Krieg
Black willow
Black willows, or swamp willows, are sometimes mistaken as "trash trees" but are actually deeply beneficial to wildlife and battling erosion.
I was raised on a special tract of land that straddles the line between St. Tammany and Washington Parishes. A slow moving, often clear creek surrounds my family’s land, underneath a wonderfully diverse forest made up of ancient sweet bay magnolias, tulip poplars, and swamp titis. Native azaleas and elderberry sprawl and arch over the sunny edges of the creek.
One of the most bizarre looking trees, the Louisiana tung tree, also grows throughout our woods, finding itself happy in clearings where sunlight touches the forest floor in plenty. When I was a little girl, one grew right outside my window. It was interesting to see as a single specimen, with its bizarre lanky form and giant tropical heart-shaped leaves with their lovely fall color. We threw the giant fruit at each other as children. Our road is even called “Louisiana Tung Road.”
When I left for college, I thought about tung trees a lot less. One day, a few years into university, I spotted one behind the geoscience building. That tree, in the middle of the city, reminded me of those trees of my childhood merriment. I quickly learned it was not native flora (names don’t always tell the truth after all), but an animate and thriving remnant of plantation-era past. These trees, in our region, came from seed brought from China a hundred years ago that were sown at Money Hill Plantation, a once thriving tung oil operation, just a stone’s throw from our property. Our area was chosen by the U.S. government as an “ideal” place to grow these strange trees. There was oil to be made, money to be had, and the U.S. wanted its part in it.
Fifteen years of working with natives later, I see these trees differently. Despite their strange, charming features, tung trees are taking over my precious woods. They seed profusely and grow quickly. Over the years, I have seen them choke out species that have been there for thousands of years.
Some people like to call trees like the Tung “trash trees.” Personally, I can’t bear to call any tree or plant “trash,” no matter where it comes from or what it does to my woods. They, after all, are innocent and are just doing what, evolutionarily, they were created to do: grow, seed, and spread.
Personally, I can’t bear to call any tree or plant “trash,” no matter where it comes from or what it does to my woods.
No, the blame here lies on us, humans—and our inclination to intervene. Throughout all of history, humans have moved plants around, occasionally for pure beauty and enjoyment, sometimes for medicine, very often with the hopes of new cash crops and riches. Whatever the reason, pretty commonly the newly transplanted exotic plant out competes the complex local systems that have been slowly evolving together over millennia, setting things off-kilter.
From this phenomenon emerge exotic trees dubbed “trash” for their invasiveness and damage to our natural environments, including: tung, tallow, paper mulberry, Chinese privet, and parasols.
However, along the way certain natives—especially ones that are fast-growing, quick-to-seed, and highly-adaptable—got thrown beneath that umbrella, too. Recently, I went by my friend Ana’s house in the garden district of Baton Rouge, where she proudly showed me the hackberry tree she had just planted in her small front yard. She said that her friend down the road couldn’t believe she would purposely plant and encourage a hackberry tree, a “trash tree.”
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Below I want to highlight a handful of other common “trash trees” that are actually lovely native trees. Having evolved and grown naturally here for millennia, these trees all have a purpose in our native ecosystems. They also tell us a good bit about the unique natural history of the lower Mississippi alluvial floodplain, as well as how this big river shapes our landscapes in southern Louisiana. All except the cherry laurel can handle flooding in ways other trees cannot. These trees show up as survivors where forests and landscapes have been decimated. They often appear and rejuvenate on their own without much human help. A Louisiana without these trees would be a lot more barren a place. And perhaps most importantly, as native trees do, they are all wildlife powerhouses. Together they host incredible amounts of pollinators, give up large quantities of food, and offer more homes to birds and small mammals than we could ever imagine. They live through drought, deluge, pollution, and human havoc. They carry on.
I find it's often the intersection of these powerhouse natives and the urban environment (tight quarters, abundance of human activity) that cause the “problems” that give them a rough reputation. But I believe all of these trees’ “bad characteristics” can be overlooked and even embraced.
Swamp Willow/Black Willow, Salix nigra
You can find the swamp willow growing throughout our various waterways. They grow in enormous stands along the Mississippi River, which is my favorite place to interact with them. They offer great wildlife refuge, are an excellent erosion stabilizing agent, and are a keystone species in riparian areas throughout their range. Their weeping manner makes them one of the most beautiful trees on this list for me. There is nothing like fishing beneath them on a windy day.
Sweet Gum, Liquidambar styraciflua
I cannot tell you how often people ask me why I would ever plant a sweet gum. As far as I am concerned, the fall color is a good enough answer alone! Those seed balls that people love to hate are beloved by birds in the winter and a crucial foodsource for various types of wildlife. The tree also has a dense canopy, offering great shelter.
Water Oak, Quercus nigra
Water oaks are famous “widow makers,” as some like to say. More than anything else, they are known for their quick growth and short life spans; they rot, break, and topple over often. But, what people do not realize is that the natural world needs trees like these. Due to this rapid growth and short life span, the water oak is an excellent housing unit for wildlife—especially cavity-nesting birds. Their role in the natural world is to be a “transitional species”. When a forest is rejuvenating, they come to the job first, popping up and growing fast. Then, when the slower-growing hardwoods get to where they need to be, the water oaks die out to offer them space. Sometimes the reasons why humans don't like a plant are, in turn, the exact characteristics that benefit our ecosystems and what they evolved to offer our world.
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Hackberry, Celtis laevigata
I find these guys all over the bottomland hardwood forests and swampy areas I like to explore. You can always identify a hackberry by their interesting corky bark. They are characterized also by a soft, close-grained wood great for furniture making and other building uses. Unlike the water oak, these are a long-lived species. Sometimes the wildlife activity around the hackberry’s fruit is an actual party. You can see the commotion from afar. Another name for the hackberry is sugarberry, which explains the fight for its fruit. The hackberry is also a larval host to numerous butterflies and moths.
Cherry Laurel, Prunus caroliniana
Distinct from the other trees included here, the cherry laurel cannot withstand flooding, but it does seem to grow in almost any other type of environment. Once established, the trees are incredibly drought tolerant. Cherry laurels are evergreen, and can be a nice native option for privacy screening and year-long greenery. This tree also offers great amounts of early spring nectar, and is an excellent city tree in that it has an ability to absorb high amounts of man-made pollutants.
I find it's often the intersection of these powerhouse natives and the urban environment (tight quarters, abundance of human activity) that cause the “problems” that give them a rough reputation. But I believe all of these trees’ “bad characteristics” can be overlooked and even embraced with some learned tree identification skills and a bit of knowledge, which can aid us in better placement/planting of trees, better control of where they pop up, more thoughtful pruning agendas, and long-term care.