In defense of the black walnut tree

The black walnut tree is having a tough time finding the love and respect it needs these days.

Our black walnut trees grow in New York State, so we’ll review the evidence of their ongoing struggle for positive recognition starting there. Check out the presence of black walnut trees in the U.S. Forest Service’s New York Forest Inventory results. Spoiler: black walnut hardly registers, indicating that the tree is not seen as particularly key to the 63% of in-state land considered forest. The first mention of black walnut in this 100+ page report is in the Appendix as a “tree found on key tree plots”, the academic equivalent of “meh”. This New York-focused native tree planting guide simply ignores the native black walnut tree despite practically every long-term resident of central and western New York knowing someone who owns one.  Even more discouraging, most major land grant universities have published articles with titles like “black walnut toxicity”, warning readers that this tree does not necessarily play well with certain others and advising landowners to think twice before considering the black walnut as a landscaping tree. With press this negative, it’s not hard to see why black walnut struggles to be included on everyone’s “favorite big tree” list.

“A thing which I regret, and which I will try to remedy some time, is that I have never in my life planted a walnut. Nobody does plant them nowadays-when you see a walnut it is almost invariably an old tree. If you plant a walnut you are planting it for your grandchildren, and who cares a damn for his grandchildren?”

~ George Orwell


This pattern of digital disrespect through neglect, omission or outright hostility would lead the curious dabbler to believe that the black walnut just isn’t a desirable tree. It’s messy. It’s unfriendly to other plants. The incentives to plant black walnut trees aren’t obvious unless one’s goal is to grow valuable hardwood to probably benefit the grandkids or someday-grandkids. So how does this apparent black walnut apathy-at-best reconcile with information which links the Haudenosaunee (the Native American nations more commonly known as the Iroquois Confederacy and whose historical territory was upstate New York) to black walnut advocacy? The key research finding is that black walnut trees were often observed around Haudenosaunee village sites or even, as has been suggested, almost exclusively within 5 km of village sites. Such a distribution pattern would suggest a prized tree, not a problem tree. These findings suggest that people went out of their way to make sure black walnut trees had a competitive edge over other trees and were easily accessible to the people who cared about them. Black walnut tree biology hasn’t changed that much over the last few hundred years, so what did change … and is it important now?

Travel back about 300 years in your mind to a Haudenosaunee village and consider what day-to-day worries would dominate. The Haudenosaunee needed to be able to survive cold winters without electricity, synthetic insulation, long-distance transport, furnaces, stoves or other amenities now considered necessities and supplied by the global economy. Their bodies would need more energy, not less, during the cold months and available to meet this need would be such food reserves as they had been able to produce and preserve plus any anything additional that could be obtained through ongoing hunting and/or fishing. Black walnuts are rich in oil, grow without the need for care and once husked but not shelled will stay good for months if not years. The only way nature could design a better winter survival food would be to make it easier to get the nutmeat out of the shells and to make annual yield more predictable. The Haudenosaunee baked black walnut nutmeat into cornbread and simmered the cracked nuts in water to extract oil. It would be interesting to know whether villages with more black walnut or other kinds of nut trees nearby managed the winter better than those without.

That was back then. If Americans now face hunger they are more likely to associate this problem with the economy or politics than winter. Our great challenge isn’t making it through the cold season, it’s figuring out how we will manage the collective resources of the country in a manner that supports people and doesn’t continue to degrade the ecological systems on which we depend. Here again, with this present-day challenge, the black walnut tree can assist but only will if we, like the Haudenosaunee, recognize and take advantage of this potential help on offer. Climate-smart agriculture is how we will eventually deliver food security under changing environmental conditions. The currently wide geographic range of the black walnut tree demonstrates that the species can thrive across a similarly wide climate range. Any plant that can produce calorie and nutrient-dense food with no chemical inputs and minimal care should be warmly welcomed as a potential partner in human endeavors. It makes no sense to shun black walnuts because many types of plants won’t thrive near them; this can be easily addressed by letting black walnut trees grow in locations where this trait is not a problem. The black walnut is being subjected to an unfair standard. Consider the number of non-corn plant species that are allowed to thrive in the middle of, for example, a corn field. In comparison, the black walnut is far more forgiving.

We should be rolling out the welcome mat for the black walnut and more actively figuring out additional ways to use this unique North American renewable resource. Modern technology allows us to get more from this tree than was possible for the Haudenosaunee. In addition to food, black walnut shells are used by industry for blast cleaning, polishing, water filtration (oil/water separation) and more. Processed black walnut shells are useful at home, too, with applications which include home cleaning, personal care and making non-skid paint. We’ve figured out how to make stainless steel cleaner out of bar soap and black walnut shells. No matter how they are used, renewable and biodegradable black walnut shells often displace non-renewable alternatives without sacrificing performance. It’s impressive that one plant can produce high-quality food, raw material for industrial and household products, grow the national hardwood resource base and enhance animal habitat all at the same time and do this using mostly non-agricultural land and no synthetic chemical inputs. The fact that most black walnuts are left lying on the ground every year is proof positive that we’ve hardly begun to realize the value which could be extracted from standing black walnut trees, let alone black walnut trees yet to be planted.

“Early colonists soon discovered the eastern black walnut, (juglans nigra), a native to North America. The great dimension of the trees made it a conspicuous marker of the fertility of the land.” (McComb Daily, 2014)

Far more than many other tree species, black walnuts need people. Black walnuts trees seeded without human intervention are only found near other black walnut trees because squirrels bury nuts close to where they find them. Shade-intolerant young black walnut trees can’t successfully compete underneath a well-developed forest canopy. Therefore, the area for black walnut tree expansion without human intervention is limited to disturbed areas which could eventually become forest (areas with few trees but enough rain to support trees) and near where black walnut trees are already growing. There’s a lot of competition for these types of spaces and, as it turns out, most of the competition grows faster than black walnut trees.

When we harvest the best trees and leave those less desirable standing, we promote survival of the less fit.

The vast majority of standing black walnut trees are owned by farmers and miscellaneous private individuals, in sharp contrast to the conifer forests of the Unites States which are largely owned by the United States Government or commercial forest products companies. This means that long-term black walnut success really is a tree popularity contest. What happens on the land of today’s tree owners is what will write the future story of the black walnut. Whether the black walnut population will grow or decline is likely a function of how much current tree owners like their black walnut trees. If the broad spectrum of individuals who are black walnut tree owners don’t like their trees, the fate of the species is sadly predictable.

We’ll know that the tide has turned for black walnuts when people see them on the ground and think “resource” not “yard waste”. Not everyone thinks “yard waste”. Hammons Products Company, in Missouri, processes roughly 25 million pounds of nuts annually and most of those are grown and gathered by independent growers located within a few hundred miles of their processing plant so those tree owners must see their black walnuts as a resource. Our company, Black Squirrel Farms, is a tiny little company in New York with about 80 mature black walnut trees of our own but we are running a local black walnut collection program to serve nearby growers and if you’ve got mature black walnut trees in the Finger Lakes area of New York, we would love to have you join our program. Even if you don’t have black walnut trees or live in the Finger Lakes area of New York, you can help. Eat black walnuts; we’ll have shelled black walnuts for sale online in Spring 2022 but our supply will be limited and if you can’t buy them from us, buy from someone else. Give some of the non-intuitive uses of black walnut shells a try, like our anti-skid additive for paint. Help us find and publish new and heritage black walnut recipes by sending yours to Let’s make the black walnut popular again, 300+ years later.

It may turn out that in the long run we need black walnut trees as much as they need us now.

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