Among all manner of disturbed natural sites, from roadsides to patio edges, some of the first tufty growths to be seen are actually small trees.
With dense collections of small leaves connected together to main stems, known scientifically as pinnately compound leaves, these plants are unique looking compared to most other quickly-colonizing plants, and almost have the appearance of a wisteria with thorns.
In only a few years, these small growths will turn into the black locust trees that frequently dot our local landscapes.
Black locusts are sometimes looked down upon by the gardener for their ability to quickly move into any cleared space, where their thorny branches and deep tap root make removal a pain even in the best of circumstances.
They also have a reputation for a relatively rapid decline, wherein boring insects and fungal diseases render the tree weak and susceptible to breakage in inclement weather. These myths, while rooted in some truth, are able to be avoided through proper care and planting of any new or existing black locust trees on your property.
In fact, black locusts have been an important tree for North American peoples for thousands of years, and should be incorporated into your landscapes whenever possible.
You might not be able to tell by immediately looking at them, but black locust trees are some of North America’s supertrees.
Black locusts are in the pea family, and like many other peas, they have developed symbiotic relationships with microbes that transform atmospheric nitrogen into a usable form, enriching the soil around them as they grow.
Black locust wood is incredibly dense and rot resistant, has a higher beam strength and fuel value than any other North American tree, and produces dense clusters of flowers in the spring that are an important nectar source for pollinators.
These are some of the reasons that black locusts were relied on heavily by European colonists when they settled here, and these trees were used especially in construction projects requiring ground contact.
Earlier cultures who lived here also recognized the unique strength of the wood, and black locust was reportedly the main component used in the hunting bows of many indigenous American societies.
Multiple attempts have been made throughout the country to grow black locust commercially, but the vim and vigor of the tree is somewhat matched by the tenacity of their most immediate natural threat – the locust borer beetle.
Frolicking among blooms in the late summer and fall, especially in areas with a goldenrod patch or two, are brilliantly striped black and yellow beetles. Almost an inch long, these large beetles mimic the bees and wasps who also frequent goldenrod.
Despite their coloration these are not hunters. Locust borers feed on the soft and tasty interior of only one organism – black locust trees. While you may balk at these hungry insects after hearing about how amazing black locusts are, locust borers also serve a wide variety of functions beyond their simple consumption of wood, and I would even venture to say that at the very least, other animals re-use borer tunnels after they emerge.
Although tenacious, locust borer beetles are native to North America. Studies have found that, unsurprisingly, strong and healthy trees are able to ward off and withstand borer attacks much easier than trees in stressful locations.
Even though black locusts readily sprout and grow in even the poorest locations, try and plant any new additions in rich, well drained soil. Borers also enter trees in large, ragged wounds.
If you notice any torn or hanging branches, make sure to trim them ASAP to close off any possible entry points. Leave a ‘nub’ of a few inches on any branches you trim to allow the tree the space it needs to properly seal the wound.
Brannen Basham is a writer and horticulturalist. Together with his wife, Jill Jacobs, he owns Spriggly’s Beescaping, focused on nature education and habitat restoration. He recently published his first book, “A Guide to the Wonderful World Around Us: Notes on Nature.” For more information visit www.sprigglys.com.