Have you admired a locust tree recently? These interesting trees can usually be identified by their clusters of small leaves and particularly rough bark.
Locusts are important colonizers of disturbed natural areas, as they are some of the first plants that will begin to explore and settle into a cleared space. Once established, their thorny branches and deep taproot make removal a pain even in the best of circumstances. They have a reputation for a relatively rapid decline compared to other trees, due to boring insects and fungal diseases rendering 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 locust trees on your property. In fact, locust trees have been an important tree for the people in our area for thousands of years, and should be incorporated into your landscapes whenever possible.
Locusts are some of North America’s supertrees. They 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. Many of these “nitrogen-fixing” plants feature special nooks and crannies in their roots that serve to harbor populations of these beneficial bacteria and fungi.
They often also take most of the credit for the work of their microscopic tenants. In mountain forests, black locusts are more common, however there are also a few honey locusts in the area as well, preferring to grow in lower-lying areas. 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 they were relied on heavily by European colonists when they settled here, using these trees 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 strong, 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 soils, 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 give the space needed to properly seal the wound.
Brannen Basham and his wife, Jill Jacobs, operate Spriggly’s Beescaping, a business dedicated to the preservation of pollinators. He can be reached at email@example.com.