Have you unfriended the black walnut tree in your yard? You're not alone.
Many disgruntled homeowners are grousing about black walnut trees this fall. The formerly bright green "tennis ball" fruits that weighed down the branches in September are now blackened blobs of decomposing husks strewed about the ground, staining sidewalks, cluttering driveways, and littering the yard.
The sheer volume of botanical jetsam presents a challenge to those who like a tidy yard, and the chemical properties -- notably the indelible stain walnuts leave -- pose a problem as well.
The very nature of the walnut, however, makes it one of the most useful native fruits in our flora. You can eat it, clean with it, use it to make cosmetics and paints and add it as filler in dynamite. Wow! What more can you ask for from a nut?
Edibility is one of the first things people think of when considering plants "useful." The walnut ranks high on the edibility charts. Indigenous people have included walnuts in their diets for hundreds of years. European Americans, quite familiar with walnuts from the Old World, readily adopted the North American black walnut in their cuisine.
The walnut is not only edible, it's highly nutritious. Nutrient analysis reveals that walnuts supply omega-3 fat (a "good fat"), essential minerals, antioxidants, and fiber.
Looking more closely at the edible benefits of walnuts, research scientists have come up with some interesting and potentially far-reaching results. In 2006 Science Daily reported that "consuming a handful of raw walnuts along with meals high in saturated fat appears to limit the ability of the harmful fat to damage arteries." The fat content in walnuts is "protective fat," according to University of Maryland professor Robert Vogel. As cited by Science Daily, Vogel said the fat from walnuts "actually undoes some of the detrimental effects of a high-saturated-fat diet."
Equally promising are studies linking walnuts to lower cholesterol levels, blood pressure and stress. Research scientist Sheila West of Pennsylvania State University, as quoted by Science Daily in a 2010 article, said results of her research "are in agreement with several recent studies showing walnuts can reduce cholesterol and blood pressure. This work suggests that blood pressure is also reduced when a person is exposed to stress in their daily life."
Walnuts were part of the pharmacopeia of folk medicine in the 18th and 19th centuries and they hold promise in medicine today. The Comanche utilized the husk in a treatment for ringworm. The Houma people used an infusion of walnut husks as a dermatologic aid. American Pioneers used black walnut extract as an astringent, a laxative, a vermifuge -- and as a treatment for scorpion bites.
Today scientists are keeping an eye on Black Walnut for its potential in cancer treatment. According to the American Cancer Society, "studies in the lab have suggested that a compound called juglone, which is present in black walnut, may have some anti-tumor activity."
Studies have yet to be conducted with humans to determine the efficacy of juglone to prevent cancer in people.
Another use of black walnut is revealed to anyone who picks up a broken black walnut fruit in his hands. The result is an indelible dark coloring. This very property, when put to good use, lends itself to natural dye-making. One of the only dyes that doesn't require a mordant, black walnut was a principle coloring agent in North America prior to the 20th century.
Black walnut fruit has some amazing applications in industry. A Virginia Tech forest products publication elaborated on uses of walnut hulls in metal cleaning and polishing, oil well drilling, painting, cosmetics and explosives. Processed hulls are also used as gas mask filters. The list, it seems, is endless.
Knowing the eclectic uses of the black walnut may assuage the grumbling of those who face the formidable task of cleaning up bushels of the blackening fruit. These native fruits need not be a curse. They may be considered a blessing and a bountiful one at that.
• Valerie Blaine is a naturalist with the Forest Preserve District of Kane County. You may reach her with questions or comments by emailing firstname.lastname@example.org.