The Plant Press

From The Plant Press, Vol. 24, No. 3, July 2021.

How to find black walnuts

By Julia Beros

It’s the kind of object you might stumble over while on a walk and kick around with your foot accidentally, a palm sized sphere wrapped in a green and rumpled husk pocked like an eczema flare up, with a density that makes a crisp ‘plunk’ when it falls from the tree. It’s the kind of object you pick up for only a moment, but it leaves a stain of stench and tint on your fingers and a lingering waft of spicy and bright aroma along your trail. This time of year (mid-to-late June) is when these fruits begin to plump up and get picked too young by squirrels with an appetite for impatience. These black walnuts, the young fruits of Juglans nigra, begin to litter the forest floor as summer progresses into a dense heat, and for some they are a prized ingredient in a family tradition.

It’s this mid-to-late June time of year, according to the notes in my father’s book, when it’s right to begin collecting young black walnuts. It’s this time of year when large glass jars sit on the front porch, filled nearly to the lip with a thick inky liquid packed with vaguely identifiable objects that bob as the pressure shifts inside and stews under the height of summer sun. This is how my father makes orahovica, a walnut liqueur that is brewed on porches and windowsills that look out over the Dalmatian coast. Here in Maryland he continues to brew using the secrets from his family’s recipes, and is now developing his own confidential techniques with local ingredients to enjoy a familiar flavor.

In Croatia homemade liqueurs like orahovica (and its herbal cousin travarica) make use of abundant local plants and the by-products from wine making (brandy) to create richly aromatic and punchy sips of aperitifs, often enjoyed in the company of guests or as a medicinal nightcap. As each home has their own “perfected” recipe whether it be the “perfect” ratio of ingredients, the “perfect” source of walnuts, the “perfect” windowsill with the “perfect” conditions, or the “perfect” home-life dynamic, each home has an inimitable version of the same drink. It’s the kind of beverage that you are handed when you are welcomed into a neighbor’s home as an introduction to get to know them better, each sip revealing more about the brewer. These traditional brandy drinks were once the libation of choice to share with friends but have become less and less popular with newer generations (perhaps due to the slightly laborious process). Opting for “colas and other soft drinks,” my dad condemns, few people keep up the home-brew tradition. While it may be harder these days to find people selling their hooch at the markets, and fewer glass jars guarding windowsills, these traditional recipes are still passed down like family heirlooms. 

Here in Maryland the trees of Juglans nigra grow stoic and calm throughout the region. A native tree to the Eastern U.S., the black walnut is distinguishable for its dark deeply grooved bark, creating linear patterns, and its often sprawling canopy of large alternate compound leaves. It is described as one of the “most valuable and beautiful native trees” in the Peterson Eastern Trees Field Guide, and is prized for its durable and easily workable wood, reiterated in Eliot Wigginton's 1975 book on summer and fall wild plant foods, Foxfire 3. Both sources make note that for this reason most large black walnut trees have been felled for furniture and other trades leading to overharvesting. Notable ornithologist, and first appointed curator of birds at the Smithsonian Institution, Robert Ridgway even made great efforts to express concern over the rapid deforestation in his native Mississippi valley region between 1876 and 1881, writing to then Assistant Secretary Spencer Fullerton Baird and including photographs of himself enjoying the pleasant shade afforded by the black walnuts. 

Historically black walnut wood has been used for gunstock and cabinetry, the bark for tanning, the nut husks for dyeing, the bruised nuts for stunning fish for easier capture, and the trees are said to have been frequently planted as ornamentals, marking old home-sites “long after the dwellings are gone.” Juglans nigra is also known to be an antagonistic companion plant, for its roots secrete a toxic substance, juglone, making its root zone nearly uninhabitable by other plants. The fruits are eaten by human, mouse, and squirrel alike, all enjoying the uniquely acerbic and rich taste easily discernible from the familiar and widely available English walnut. It is being studied for viability as a rehabilitation plant for disturbed areas and shows promise for aiding in land reclamation of mined sites. The ground shells of the fruits are used in a variety of applications in the automobile and airline industries. Despite black walnut’s purported beauty, value, and incomparable flavor, this is not a nut you will find easily in the grocery store. Nor a nut you will easily crack open. 

Growing up in Maryland, our neighbor had a black walnut tree that hung its shade and its fruits over our driveway and house. Although the clutter of walnuts rang loudly on the roof, night and day, and the risk of staining our hands while fumbling with the fruits left spots of sepia in our laundry bin, the tree inspired my father to brew orahovica like his father and mother did (each with their respective secret recipes) only using black walnuts as opposed to the more commonly used English walnut. Sadly, our neighbor had to cut the tree down (along with the nearby mulberry, another tree whose fruits often ended up in our bellies). This did not stop production though. My father set out on bike trails and neighborhoods, looking for the optimal trees, far enough away from roads and car exhaust and bountiful enough with fruit to collect for his yearly batch of brewing.

Today we walk through Rock Creek Park and I ask him how he knows when and where to harvest black walnuts. He tells me he just knows. He elaborates that the trees are very distinct, and we will surely pass one soon. He starts by searching for the right bark (although he already knows the location of the larger black walnut trees in the park, having spent time biking and walking through to map out the spots for collecting). “It’s a bit serpentine, and thickly crackled. Maybe a bit dark too,” he describes. We find a skinny and young tree, the crown so high we can’t get close to any of the leaves. 

My father takes me out to the clearing where he knows a big tree awaits. The branches outstretched and buoyant like the arms of a marionette held at length by a string and the shade stippling the grass with tiny patches of light. He pulls a leaf closer to examine, describing to me its distinctions. “I see,” I answer, “these are alternate compound, and the leaflets look slightly toothed. It seems the terminal leaflet is lacking on most of these leaves,” I continue. “Compound?” he asks me, and I describe to him that the “leaf” is the entirety of the multiple leaflets he was seeing individually. We found ourselves looking at the same tree describing the same things with a different vocabulary. This was our coincidence of botanical knowledge: mine relayed through field books and schoolwork and his transferred through generations of keen observation and culinary heritage. We continued to converse over the walnut branches describing it in detail, meanwhile the dense overripe fruits thumped to the ground and began rolling down the hill.

The flora of the D.C. region is plentiful with gastronomic foraging, abundant with plants and foods both rooted in indigenous traditions and able to make connections with those of immigrant cultures. Through local plants like the bright raspberries that speckle hillsides and creep along the rivers, dandelions and plantain leaves, or the elusively in-demand pawpaws, there is a plethora of ways to learn about and explore the botanic and cultural history of food. For my family the black walnut has become something more than a beautiful native tree that provides ecological, agricultural, and industrial value, it ties us back to my father’s family traditions and to the glass jar windowsills of the Dalmatian coast.