FIELD NOTES BLOG

All About Nuts

Emma Zimmerman
October 24, 2024

Fall is a season of change. Changing colors, changing weather, changing days. And though it’s a time where the world seems to slow down, nature is in full transition at rampant speed, getting ready for the cold, harsh months ahead. Trees shed their leaves, conserving energy for the long winter, while animals gather food and shelters, preparing for the cold. Every species is instinctively preparing for survival. And in the midst of all these preparations, one small yet vital element takes center stage: the nut.


Colloquially, we often refer to any dried seed or hard fruit as a "nut." Botanically, however, the term "nut" refers to a particular kind of dry fruit that has a single seed, a hard shell, and a protective husk.  Pecans, hickory nuts, acorns, and walnuts all fall under this strict botanical definition, whereas commonly labeled "nuts" such as peanuts (legumes) and almonds (drupes) don’t meet the criteria. Whether or not one is concerned with these taxonomic distinctions or not, one fact remains: nut season has arrived here in Northern Illinois. 

Trees like hickories, walnuts, and oaks produce various kinds of nuts, which are the trees' mast. “Mast” is the botanical term for the food that trees and shrubs produce, which is stored and eaten by wildlife. While trees produce mast annually, certain years, known as "mast years," see an exceptional abundance of nuts. These mast years occur irregularly, around every 2–5 years, and the forest floor becomes carpeted with nuts. This overproduction plays a vital role in forest regeneration. By overwhelming the animals that feed on these nuts, trees ensure that some nuts escape consumption, allowing them to germinate into new saplings. If trees produced only a small number of nuts each year, most would be consumed, leaving no seeds to develop into the next generation of trees. However, this event does not come without cost. Producing nuts in such large quantities requires significant energy, so trees have to conserve their resources, saving up for these occasional mast years.

What’s most fascinating about mast years is their synchrony. Even though each tree is an individual being, with individual  energy reserves, they all mast at the same time. To quote Robin Wall Kimmerer, “If one tree fruits, they all fruit—there are no soloists. Not one tree in a grove, but the whole grove; not one grove in the forest, but every grove; all across the county and all across the state. The trees act not as individuals, but somehow as a collective.” In Northern Illinois, our most recent mast year was 2023, meaning that this year we can expect fewer nuts compared to last.

Something I admire about nuts is their subtle presence in nature. Unlike the vibrant colors and fragrant aromas of summer fruits, nuts don't demand our attention. Instead, they remain patiently in the background, protected by tough shells and husks, patiently waiting for their time to come. They're prepared for the season ahead, and are designed to endure winter conditions—they store well and are packed with protein and fats, essential nutrients when resources are scarce. They're a lifesource for many animals in our region, and have been one for people, too. Nuts have significant importance both biologically and culturally, and to honor that, we are going to do a deep dive into three nuts that you’re probably beginning to see around: the hickory, the walnut, and, of course, the acorn. 

Walnut :

Black Walnut Tree, courtesy of Wikimedia Commons

Black walnut trees (Juglans nigra) hold deep ethnobotanical significance in North America, where Indigenous peoples and early settlers utilized nearly every part of the tree for food, medicine, and practical uses. The nuts are exceptionally nutritious, rich in protein, and healthy fats—black walnuts, in fact, contain more protein than any other nut. Indigenous groups, including the Cherokee, Delaware, and Meskwaki, ground the nuts into meal or pressed them for oil, making them an important source of sustenance, particularly during the harsh winter months when other food sources were limited. Today, black walnuts have shiften from a culinary staple item to more of a topping or high protien snack. 


Beyond their culinary value, black walnuts played an important role in traditional medicine. Many indigenous peoples used the bark of the black walnut tree for its medicinal properties. Teas made from the bark served as cathartics or emetics, while the bark itself was chewed or applied to aid ailments such as toothaches, snake bites, and headaches. The natural tannins in the walnut's hulls were also used as a natural dye, which creates a rich, earthy tone for textiles and basketry. This dye is so strong that it will often dye your skin- you might be familiar with this if youve ever picked up an unhusked walnut!

In addition to food and medicine, black walnut wood is highly sought after for its strength and durability. The dense, sturdy wood has been, and continues to be  used to craft tools, build furniture, and even construct homes. 


Adaptations: One of the black walnut’s unique adaptations is its allelopathic nature. The tree produces a chemical called juglone, a natural toxin that inhibits the growth of many other plant species around it. This chemical defense mechanism helps the tree reduce competition for sunlight, water, and nutrients- elements that are vital for survival. Juglone, found in the highest concentrations in the tree's roots, buds, and nut hulls, interferes with the energy production needed for photosynthesis in sensitive plants, causing them to yellow, wilt, and eventually die. This toxic effect makes it challenging to grow certain plants near a black walnut tree, so gardeners need to be cautious when planting around these trees!

Hickory:

The term “hickory” comes from the Virginia Algonquian word pawcohiccora, referring to the nut meat or a milky beverage made from hickory nuts. Shagbark hickory trees (Carya ovata) were an essential resource for Indigenous peoples, who relied on their nuts for both food and drink. Hickory nut milk, rich and flavorful, was incorporated into various dishes such as corn cakes, kanuchi (a type of hickory nut soup), and hominy. Even today, hickory nuts serve as a substitute for pecans in colder climates like Northern Illinois, playing a similar culinary role in pies, baked goods, and savory dishes. Hickory trees are not just a food source for people but also for wildlife. Red and gray squirrels, raccoons, chipmunks, and mice all rely on hickory nuts for sustenance, especially as they prepare for the winter months. 


Beyond their edible value, hickory trees were highly valued for their practical uses. The flexible bark was ideal for crafting bows, a critical tool for hunting among many Indigenous groups. The wood, known for its toughness and resilience, was used to create blowgun darts, arrow shafts, tool handles, barrel hoops, and even corn beaters. Today, hickory wood is prized for its excellent burning qualities, making it a top choice for firewood. Shagbark hickory, in particular, became famous for its role in smoking meat, as it imparted a distinct, rich flavor to food.

Acorn:

Oak trees, and their mast, acorns, have been an important and iconic symbol of the landscape for thousands of years. During this time, acorns have been a reliable and essential food source for humans. Though they contain tannins—bitter compounds that are inedible in their raw state—Indigenous peoples developed techniques to remove these tannins through leaching or toasting. Once the tannins were removed, acorns could be ground into flour and used to make breads, cakes, or porridges. Acorn flour, often stored in underground pits, provided a nutritious and long-lasting food supply throughout the winter months.


Oak trees, however, provide more than just acorns. The bark of oak trees had medicinal applications, valued for its astringent properties to treat wounds, burns, and digestive ailments. The wood, known for its strength and durability, is utilized for constructing homes, tools, and furniture. Oak leaves were even used in food preparation, often serving as natural wrappers for dough when baking bread.


Oak trees were also central to land management practices. Many oak species are fire-tolerant, and their acorns readily sprout after fire or grazing. Indigenous communities practiced prescribed burns to clear underbrush and promote the growth of oak trees, ensuring a steady supply of acorns and timber. These controlled burns helped maintain healthy oak stands, which were integral to both human life and the surrounding ecosystems. To learn more about oaks, check out Elly's Oak-tober blog!


In each of these trees—black walnut, hickory, and oak—we see not only valuable food sources but also the foundation for tools, medicine, and land management practices that sustained Indigenous communities for generations. These trees, and the mast the produce, are a testament to the deep connection between people and nature, offering lessons in resilience, adaptation, and balance within the natural world.

Sources:

Braiding Sweetgrass by Robin Wall Kimmerer

USDA Plant Database: https://plants.usda.gov/home


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