On the morning of the fall equinox, I awoke at a Maine campsite, where the ground was sheathed with frost. The calendar page had officially flipped from summer, and when I returned to Boston, rain and cool evenings followed suit. Although most trees are still green, homeowners must be stocking up with leaf bags at the hardware store, musing about the whereabouts of a misplaced rake. I’ll admit, although I’m ready for the season, when I saw the mess of the black walnuts (Juglans nigra) littering the surface of Valley Road at the Arboretum on a recent afternoon, I had no intentions of stopping. There are certainly more understated and overlooked harbingers of autumn, plants with bashful fruit and unfamiliar names.

Yet I did stop, primarily because the afternoon sun was sinking just so, backlighting the cathedral-like canopies. The most prominent black walnuts in our collection (five members of accession 1181) arrived as seed in 1874, two years after the Arboretum was founded, and the trees have reached stately dimensions. I still would have continued onward, however, if not for the turkeys (Meleagris gallopavo). They materialized silently and unbidden—ten of them—casually strutting across the road and into the walnut grove, unconcerned and unhurried. I had encountered the same birds earlier this spring, when eight were small and toddling, chaperoned by their parents. Now the youngsters were almost indistinguishable from the two adults, at least in terms of size. It was the post-work hour, when the Arboretum babbles with voices, and two stroller-pushing parents were among the first onlookers to pause. This seemed appropriate—an unofficial assemblage of families, people and birds alike.

Black walnuts on road and in grass
A scattering of black walnuts (Juglans nigra) offers a sign of fall. Jonathan Damery

I followed the slow course of the turkeys, watching their heads bob rhythmically back and forth, up and down, as they nipped at grass or insects or both (but certainly not the walnuts themselves, given the thick shells and inky husks). I eventually left the birds alone and returned to the road. Now the fallen walnuts seemed like a fitting complement to the patron birds of fall cookery. Yes, we’re two months away, but like the aisles of any department store, I’m already several holidays ahead, dreaming about pecan pies and cranberry relish. The native distribution for black walnuts threads through Massachusetts. It doesn’t reach the coastline, according to maps I’ve studied, so the fruits were ostensibly absent from the near-mythological meal in 1621, when Wampanoag and English settlers convened for three days of harvest eating. In New York, however, the Haudenosaunee (the confederation of tribes often known as the Iroquois) baked nutmeats from black walnuts into cornbread. They would also simmer the cracked fruits in water, causing the rich oils to rise in a shimmering layer, which could be extracted for other cooking purposes.

Walnut oil, I have always thought, deserves broader acclaim. In southwestern France, oil is made from Persian walnuts (Juglans regia, see accession 14767*A) and is coveted and rather expensive. Producers grind the nutmeats into a paste, which is then toasted and pressed. The fruits of the black walnut have an earthier aroma than those of the classic Persian walnut—darker, more complex—and although I’ve never sampled oil from the black walnut, my gastronomic imagination is officially stirred. The French product is delectable, and if it goes well drizzled on watercress salad and duck confit, wouldn’t it be appropriate to have the black-walnut equivalent garnishing a slice of turkey on the Thanksgiving spread? Incidentally, although much of the current black-walnut production passes through one Missouri-based cracking plant, down from ten plants sixty years ago, ongoing horticultural research has improved the viability of orchard production, and in addition to the cracked nutmeats you find at some grocery stores, I recently noticed that small bottles of black-walnut oil can be purchased online.

The day after watching the turkeys, I passed the black-walnut grove once more, and I saw that the horticulture crew had immaculately cleaned the surface of the road. The same was true of smaller fruits from an Arizona walnut (Juglans major, accession 10968*A), which had littered Bussey Road, not far from the black walnuts. (The Arboretum cultivates eight walnut species, along with one hybrid.) Given that organic compounds in walnut husks can be used as a natural dye, readily darkening fingers if touched, I was somewhat relieved. Fears about staining my white sneakers abated. Fall may have officially arrived, but at least on the Arboretum roads, we can thankfully forget for just a little bit longer.