Horn Farm Center for Agricultural Education

Tag Archive: Elderberry

Finding Wonder in the Smallest Surprises

Building biodiversity is a key component of regenerative farming. When nature inspires how we design our food systems, a colorful cast of characters is bound to follow. That’s why we’re always excited to spot an unfamiliar or eye-catching insect in the field!

Don’t be fooled by their small stature: insects can provide a lot of ecological insights. In documenting both new and frequent sightings, we’ll explore questions like: Who do they eat? Who eats them? What habitats do they prefer? What plants do they depend on? If some consider them a “pest,” why? Is the judgment valid? Might there be a missing check – a predator or parasitoid, say – that could quell their impact? The vast majority of insects – many say over 99% – are harmless or beneficial to humans, so it’s worth taking the time to better understand those with whom we share our garden and farm ecosystems.

The 2026 growing season has been no exception for spotting cool bugs with even cooler life histories. Below are a few of the latest visitors to greet our staff, students, and volunteers this year. As you’ll see, even the smallest creatures can fill us with wonder, giving us countless pathways to connect with our local landscape.

Walnut Sphinx Moth (Amorpha juglandis)

Walnut Sphinx Moth (Amorpha juglandis), photographed May 18, 2026

With so many black walnut trees surrounding our growing field, the name for this common moth came as no surprise. As caterpillars, walnut sphinx moths eat the leaves of black walnut (Juglans nigra) and related trees like butternut and hickories. Interestingly, they also consume hazelnut leaves. The Horn Farm’s multifunctional riparian buffer includes hundreds of American hazelnuts (Corylus americana) planted to protect sensitive land while producing edible nuts. So, if nothing else, the Horn Farm apparently provides pristine reproductive habitat for Amorpha juglandis!

But this quaint lepidopteran – belonging to the order of insects that includes butterflies, moths, and skippers – comes from surprisingly ferocious stock. Walnut sphinx moth caterpillars are known to thrash, bite, and even squeal when distrurbed. While the squealing reaches frequencies undetectable by the human ear, birds perceive the sounds and may become startled enough to skip the screaming caterpillars for their next meal.

But all this protest isn’t just pandemonium. Researchers have noticed how the caterpillar’s squeals resemble avian alarm signals, similar to those used by birds to communicate the presence of nearby predators. So it’s possible that the caterpllars are deflecting hungry birds by employing false alarms. Mimicry or chaos, this adaptation proves useful for keeping bird pressure at bay, allowing many caterpillars to survive the treacherous journey to becoming moths.

Eastern Elderberry Borer (Desmocerus palliatus)

American black elderberry (Sambucus canadensis), like American hazelnut, is a hallmark of the Horn Farm’s learning landscape. Dozens of class participants and volunteers have helped our team to plant, tend, and harvest hundreds of elderberries over the years, with the goal of creating a healthier farm ecosystem while demonstrating agroforestry to our community.

So, swimming as we are in a sea of elderberries, one would expect us to come across something like the eastern elderberry borer more often. This insect has an exclusive (or as ecologists would say, obligate) relationship with elderberry, requiring it for feeding and reproduction. But it turns out the elderberry borer is elusive, even for entomolgists. Many accounts describe it to this effect: “not uncommon, but rarely seen.”

The eastern elderberry borer is a species of longhorn beetle (Cerambycidae), and among the most visibly striking of this group. Its draping, iridescent wings are crowned with brilliant orange, a type of warning coloration designed to signal toxicity to birds and other predators. Some insects merely mimic warning coloration – like the viceroy butterfly vis-à-vis the monarch – but the elderberry borer may truly be noxious. Since elderberry leaves naturally contain toxic cyanogenic glycosides, the feeding insect can accumulate these toxins and render itself undesireable to predators. Cyanogenic glycosides, by the way, are the same compounds that make elderberry leaves and raw fruits inedible to people. They transform into hydrogen cyanide when consumed. When processing elderberry fruit for medicine, we have to cook or dry them to neutralize the toxins and reap elderberry’s incredible immune-boosting benefits.

Eastern elderberry borer (Desmocerus palliatus), photographed June 9th

Now, if an insect called a “borer” rings any bells, you may be thinking of the emerald ash borer (Agrilus planipennis). This recent newcomer to North America has decimiated ash tree populations. As the name suggests, borers burrow beneath the bark of their host trees, creating holes and tunnels while feeding on essential nutrients. But not all borers are built the same. While it’s true that the larvae of the elderberry borer carve tunnels through elderberry as part of their life cycle, healthy stands of elderberry are rarely overwhelmed. Thanks to a long history of co-evolution and the borer’s generally low populations, there isn’t reason to believe this visitor poses any major encumbrance to our goals. With vigorous elderberries in an increasingly diversified community of plants and food webs, the eastern elderberry borer is simply another member of the whole.

White-Marked Tussock Moth (Orgyia leucostigma)

White-marked tussock moth (Orgyia leucostigma), photographed June 20th

This whimsical caterpillar was found clinging to a willow leaf in our basketry willow plot, making for a third new sighting among the agroforestry plantings. In fact, a volunteer discovered it while we harvested willow stems for make-your-own flower crowns at our Summer Solstice Market!

We left this stem uncut, and keenly so. Despite its rather Seussical appearance, this caterpillar is known to cause contact dermatitis, even leaving a rash on sensitive skin. That’s because of the arsenal of barbed hairs found across it’s body. These are concentrated in the antennae-like structures portruding from both ends and the four puffed clumps lining its abdomen. Even the protective cocoons these caterpillars spin during metamorphosis can cause irritation when touched!

Unlike the pickier insects above, the tussock moth is a generalist when it comes to feeding. They’ve been documented eating the foliage of over 140 plant species, primarily trees, both deciduous and coniferous. In fact, when localized population surges do occur, they can be pinned as pests in orchards and tree farms. But outbreaks are generally limited to a single season, and a healthy mix of predators, parasitoids, and pathogens – encouraged by a diversity of plants – can help prevent incursions in the first place.

It might seem unusual that the female moths are naturally flightless, a condition called brachyptery. In a world where dispersing genetics is generally encouraged, doesn’t this pose a disadvantage? As it turns out, the caterpillars themselves compensate for this shortcoming. Thanks to their ability to create short strands of fine silk, very young caterpillars can make like balloons, catching a good breeze and floating to new feeding sites. Appropriately, this travel technique is called ballooning. And with well over a hundred plant species on their menu, tussock moths are bound to land someplace where they can find a bite to eat – like the willow patch at the Horn Farm.

Black Swallowtail Caterpillar (Papilio polyxenes)

Compared with the insects above, the black swallowtail caterpillar is a relatively common find during the summer. The same goes for its stunning adult form, often seen flitting among the pollinator plots planted by our Ecological Gardener Training Program students over the years. But despite its frequency, we’re always willing to pause and admire this charming visitor to our vegetable and herb beds.

Gardeners who grow plants in the carrot family, Apiaceae, likely share our familiarity with the black swallowtail. Caterpillars feed exclusively on members of this botanical grouping, which includes celery, dill, fennel, parsley, and, of course, carrot. Apiaceae also includes wild and feral kin to our garden staples. Alongside golden alexander, wild parsnip, and Queen Anne’s lace (or wild carrot), it’s not uncommon to find black swallowtail caterpillars nonchalantly dining on some of North America’s deadliest plants, like poison hemlock and water hemlock. As any forager knows, one being’s dinner could be another’s trip to the ER!

Like the white-marked tussock moth, the black swallowtail caterpillar packs a bigger punch than its appearance suggests. Lacking in hairy armor, it conceals a secret, smelly weapon. When threatened, the caterpillar can retract its head and expose a pair of orange horns called osmeteria. The bright coloration of these horns acts as a visual warning, and they emit a foul-smelling secretion that helps to repel attackers.

Black swallowtail caterpillar (Papilio polyxenes), photographed June 29th

While mature caterpillars employ this dramatic line of defense, younger caterpillars are a bit more subtle. Many people fail to recognize the early black swallowtail caterpillars as the same species, because they are very dark and spiny with a white splotch mark mid-way down their abdomen. These features may mimic bird droppings, helping them go undetected until they grow into their greener, more recognizable form. These incredible adaptations – visual, aromatic, and otherwise – help many caterpillars complete the perilous journey to pupation, after which they emerge as the iconic butterflies we associate with the summer.

Small Wonders Abounding

Growing food in ecological ways nourishes more than just the body. When we use nature’s designs to create diverse edible ecosystems, other benefits flutter, crawl, and inch our way. A lengthy summer day tending plants and harvesting food is always brightened when we find these signs of life. They may be small, but in filling us with curiosity, wonder, and admiration for the living world, they help to nourish our connection to the local landscape.

We’re grateful for the insects who surprise us each day. We’re also grateful for the students, volunteers, and other members of the Horn Farm community who share our fascination! Check out upcoming ways to get engaged with our educational ecosystem:

For the Whole Stream: Riparian Buffers

Part 3: Beyond the Stream

Click the links to read For the Whole Stream Part 1: Upstream and Part 2: Downstream

For the Whole Stream is the first installment of a new series called the Horn Farm Ecosystem. Through periodic articles, we’ll walk the land in writing: visiting the forests, regenerative fields, and ecological action sites of the Horn Farm Center to explain our stewardship work, uplift nature, and inspire love for the land.

“… riparian buffers represent another example of an agroforestry system that’s a win-win for ecological outcomes and community well-being and livelihoods.”

– Sarah Derouin (2021)

Our visits to the Horn Farm’s riparian buffer in this blog series have covered the extensive environmental benefits of restoring plant life in streamside areas. From capturing sediments, pollutants, and carbon upstream to healing water and habitat downstream, it’s apparent that our impetus for bringing 17,000 trees and shrubs to the Horn Farm Center comes from the awareness of a beneficial feedback loop that ripples outward. At home, we can do our part to slow erosion, uptake more water, create more shade, and support a myriad of birds, insects, and aquatic life; at the same time, by helping lands and waters at home, we take the responsibility necessary to address an ailing Susquehanna River and Chesapeake Bay. Land care travels like water: fluid and pooling. In time, the small becomes sweeping.

But while the ecological benefits of buffer planting are promising, it’s important for us to avoid positioning ourselves as sidelined observers of these benefits. We are, of course, not just nature sentimentalists: we are embedded in and dependent on the land that we are restoring. Capturing water and mitigating pollutants directly impacts our wellbeing; our breathing sways in time with the respiration of the green life around us; insects pollinate our food and nurture these soils. The land right around us has always provided more materials for humans than our modern imaginations can fathom. It’s essential that we recognize these facts as climate change pushes us into increasingly unfamiliar terrain and challenges the standard of living we’ve taken for granted. Recognizing the services of our local landscapes, and RE-localizing our impacts, are the steps we need to take to secure a livable future.

With this vision of a functioning ecosystem that thrives not in our absence, but in our presence, the Horn Farm’s riparian buffers become more than healing spaces for the land.

They’re learning spaces too. We’re learning (or better, re-learning) ways to unite the needs of natural cycles with the material and caloric needs of people nearby. It’s a vision reconciling abundance in a world where ecological and societal wellbeing are often polarized: we CAN prioritize the protection of water, soil, and habitat while supplying goods for people, with annual harvests that actually promote the health of the buffer. Luckily for us, there is a word predating our work that describes this mosaic of purposes: multifunctional.

Volunteers helping out at a buffer planting workday in in the spring of 2021.
View of a vegetated area in the riparian buffer, July 2023.

The What and Why of Multifunctional Riparian Buffers

Generally speaking, a multifunctional riparian buffer is a vegetated streamside zone that improves and maintains stream health while providing direct and material benefits for the people who interact with them. These benefits often include perennial fruit and nut crops, raw natural goods like lumber and fiber, and other products that can be harvested year after year for use on site or to garner additional income.

Pennsylvania has a history of state-wide initiatives to incentivize riparian buffer planting on stream-adjacent agricultural lands, but the multifunctional appeal is a relatively new addition. In many ways, it’s strategic. One of the state’s original programs for funding buffer installations–the Conservation Reserve Enhancement Program, or CREP–prohibits farmers from generating income from the buffers it finances. While this is positive for the wild spaces it compensates, it’s a tough sell. Many farmers, especially those that operate on a small-scale, are reluctant to sacrifice acreage that could be used for crop yields. Additionally, while some to all of the planting costs are covered by the program, farmers are expected to handle the upkeep required for their riparian areas to succeed–a tall ask for folks who are already juggling demands. Taking farmland out of production like this easily sours the taste of ecological restoration despite its virtues, partly contributing to the decline in enrollment that has recently pressured the state to explore other possibilities for meeting its targets.*

So, in PA’s latest efforts to “reboot” riparian restoration, multifunctional buffer design has catapulted to the front of incentives available to streamside farmers. At the very least, it’s having a moment. From a purely economic standpoint, allowing landowners to monetize areas set aside for ecological restoration is more attractive than restoration alone. Fruit and nut crops from woody plants and florals can be lucrative, even exceeding profits of conventional row crops. Design inspiration that simultaneously favors stream health and harvest capacity is out there, primarily focused on the creation of “zones” for certain uses, with the least “touched”/most protected area residing nearest the stream, and diverse production areas spanning the periphery–hosting crops like nut trees, fruit trees, berry bushes, and ornamentals.

As we hope to capture through the Horn Farm’s buffer, the selection and placement of plants can be creative, ecologically sensible, and economically viable, not to mention restorative for us: reawakening an awareness of our material and emotional relationship to the local and natural.

Assessing a row of willows planted in our riparian buffer in advance of a volunteer workday, where we spent the morning coppicing (taking cuttings) from these plantings for basketry and brushwood bundles (December 2022).

Indeed, with design schemes, management manuals, and news features abounding (this blog being no exception), it can be easy to forget that the ideas underpinning multifunctional riparian buffers are not new. Take the entire human history of land tending, and farming land with this holistic approach becomes prominent, not peripheral. In fact, we might consider Pennsylvania’s shift to multifunctional buffer planting an echo of land use strategies and ethics that pre-date the state.

Prior to the onslaught of forest clearing for colonial monocropping, Indigenous peoples in this bioregion altered landscapes and tended forests in ways that demanded much less of the soils and waters. Versed in ecology, they engaged in the  “ … deliberate maintenance of trees and other woody perennials in fields and pastures [ … ] help(ing) meet the demand for a variety of goods and services, while ensuring the forest was not destroyed” (Alcorn, 1990). Fire ecology was one approach that spanned the area where we live. Folks leveraged routine controlled burns to supply nutrient-rich ash to soils and favor the plant types that provided food for themselves and the wildlife they hunted. The aim of this and other indigenous land practices resembles the refrains we see in the programs and articles justifying multifunctional buffers: actually building soil and ecological richness while providing for people.

These modern buffers are the outcome of land degradation and agricultural overreach, so they certainly don’t mirror the ways indigenous peoples managed landscapes as a continuous and proactive practice; but they are a way of re-remembering interactions where the land is a subject, not an object. Even as we partly impose human will on the land, our labors foster ecological well being in the long term. The land moves from a pantry to an exchange: a “give and take” rather than an unfulfilled borrowing, and what’s given is more diverse in utility and nutrition.

Multifunctionality defies the notion that regenerating ecosystems and producing a harvest are inherently at odds.

The buffer is a new collaboration of old ideas, applied with the urgency the ailing land asks of us.

Woodland Steward Wilson Alvarez teaching a class in the riparian buffer (March 2023).

Meeting the Horn Farm’s Multifunctional Buffer

So who are the flora animating our particular buffer? Before exploring some examples of what they may do for us and the ecosystem, it’s worth noting their commonalities. From the dogwoods to the willows to the sycamores, all are native, perennial, and capable of withstanding periods of extended moisture. This means that human hands in the buffer–and even human vehicles as need-be–will not compromise the integrity of the soil, water, and habitat that our planting primarily addresses. Perennial plants, once established, require less management and are therefore less intensive from an agricultural standpoint. Because of their longer staying time and adaptability (being rooted in the ground year after year instead of half a year!), they are better capable of reducing soil erosion, absorbing and diverting superfluous chemicals, conserving soil water, providing above- and below-ground habitat, withstanding weather impacts, and curbing our dependence on fossil fuels for management. Long story short, they fulfill the ecological goals of buffer planting to such a degree that visitation and harvest themselves still protect the stream.

It’s also worth noting that, to many, these perennial trees and shrubs are less familiar than the cereals, oilseeds, and vegetables of annual agriculture, and many are surprised to learn about their diverse uses. Therefore, the buffer contributes to local knowledge about what native plants have to offer us, and over time, it can be an incubator for new “markets” of raw materials that are currently outsourced because they are not locally available at scale. Sourcing local food is becoming increasingly common, but the buffer offers even more: things like medicine, oils, craft materials, timber, and biofuel–all seemingly beyond the realm of local availability, as our globalized economy would have us think.

“Human use” need not even be exclusive to our bodies and households. Most of the plants that make up the Horn Farm’s riparian buffer are capable of “live staking,” or producing shoots that can be pruned and “staked” into the ground to develop into an entirely new plant. This is an evolved characteristic of wetland- and streamside-dwelling plants: an ability to sprout from severed stems and branches as a response to living in shifting and unpredictable wet environments. For renewing natural lands at the Horn Farm Center, the implications are exciting. The landscape provides us with a place-based restoration nursery that will support future planting and rewilding, both on our 186 acres and in the places our students, volunteers, and community supporters are working to bolster nature. It should go without saying that ecological restoration falls under that header of “human use.”

Cuttings arranged for different uses during a willow coppicing volunteer workday in January 2023. The cuttings on the right are suitable for live staking. This means that they’ll bud and grow if inserted into the ground in early spring. The cuttings on the left were taken home for decoration and weaving experiments.

A sampling of the native plants that are making a home in our multifunctional riparian buffer are described in the drop-downs below:

American Hazelnut (Corylus americana)

The American hazelnut, which flourishes in disturbed sites, not only provides shelter and highly nutritious food for wildlife, but its nuts can be sold and eaten as well as used to make flours, candies, butters, oils, moisturizers, tinctures, and essential oils, all of which provide a great source of income.

Black Willow (Salix nigra)

Black willows thrive in moist, streamside soils and have fibrous roots that mitigate stream bank erosion. They contain salicylic acid with fever-reducing and pain-killing properties. Like many other shrub willows, dried and rehydrated stems can be used for weaving. For examples of willow baskets, check out Foggy Blossom Farm (Western PA) and Living Willow Farm (OH).

Elderberry (Sambucus canadensis)

Known as “Nature’s Medicine Chest,” in addition to providing fruits consumed by wildlife and flowers that beckon birds and butterflies, elderberry berries are used to make juice, pies, syrup, jellies, cough drops, and wine. Its flowers can be used in herbal tea or to flavor jellies and candies. Elderberry is also a source of vitamin C, fiber, and antioxidants, and its products sell for high prices.

American Sycamore (Platanus occidentalis)

Sycamore, one of the largest tree species in eastern North America, is exceptionally well-suited for rehabilitating degraded sites and can withstand the compacted soils and air pollution prevalent in suburban and urban areas. Its large stump provides shelter for diverse animal species, and with its grandeur, sycamore is valued for providing shade and beauty. Increasingly, like black locust (Robinia pseudoacacia), sycamore is planted in silvopasture: systems designed to incorporate trees and livestock on grazing land to help sequester carbon and improve ecological and animal wellneing.

Dozens of additional species occupy our multifunctional riparian buffer, making whole the diverse interactions that are possible in the space: food, crafts, medicine, infrastructure, live staking, habitat for nesting, breeding, feeding, and more. A full listing of these plants and their personalities may be on its way, but for now, it’s worth mentioning a few others: Arrowwood Viburnum (Viburnum dentatum), Black Raspberry (Rubus occidentalis), Black Walnut (Juglans nigra), Common Buttonbush (Cephalanthus occidentalis), Pawpaw (Asimina triloba), Pussy Willow (Salix discolor), Red Osier and Silky Dogwoods (Cornus sericea and Cornus amomum), Sandbar Willow (Salix interior), Serviceberry (Amelanchier laevis), and Smooth Alder (Alnus serrulata).

Hand-drawn map of the Horn Farm’s 6-acre multifunctional riparian buffer, created by Seasonal Land Steward Rue Sterner in summer 2022 and labeled by Education and Communications Intern Mel Beans in summer 2023. Plantings in the top left and center are differentiated by species, while the rowed plantings on the right are randomized to maximize biodiversity–a component of the Miyawaki planting method (blog forthcoming!).

Hands and Hearts on the Land

Conservation has a way of suggesting that the removal of human influence is the key requirement for the renewal of fully-functioning ecosystems. This may be true to some extent, but it leaves us with a dichotomy: where nature is preserved over “there” and we proceed with our business over “here.” What if the philosophy of conservation was applied to “here” too? What if, rather than treating our needs as sacrifices for the health of the land, we worked to temper those needs and fulfill them with sensitivity to the cycles, limitations, and teachings of the land? It may seem like a bold proposition, but our human record tells us that the way we’re living now is the exception: that living for the benefit of soil, water, and biodiversity is rooted in the human story.

Community members practicing the fundamentals of basket weaving using cuttings from willows grown at the Horn Farm Center (March 2023).

The proposition also becomes less daunting when we approach “we” locally. From the black locust tree’s durability for building materials to the medicinal offerings of elderberry, black willow, black raspberry, and others, we can recognize that biodiversity provides far more in abundance than ecosystem services and the joy of time spent in nature (though these are deeply valuable in their own right). By embracing tending and harvest as companions of land renewal, we can reacquaint ourselves with the true extent of the land’s bounty and grow in our self-sufficiency. Altogether, we can redefine our sense of home. In envisioning a relationship between land and people where both can thrive in harmony and reciprocity, our riparian buffer is a model-in-progress.

“We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.”

– Aldo Leopold

*In 2016, the PA Department of Conservation and Natural Resources set a goal of planting 95,000 acres of riparian forest buffers by 2025, in line with deadlines for federal and state Chesapeake Bay cleanup programs. Pennsylvania is currently behind on its commitments.

Sycamores, black willows, and black locusts basking in the summer sun (July 2023).

Stay tuned for our next blog on planting trees using the Miyawaki forest method, publishing in August!

We’re grateful for the funding partners who have sponsored our riparian buffer efforts:

6 acre restoration (2018):

10 acre restoration (2020):

Our heartfelt gratitude also extends to the hundreds of volunteers who have attended planting, tending, and harvest workdays between 2018 and today.

About the Authors:

Andrew Leahy

Growing up in the foothills of Ricketts Glen State Park, Andrew spent his early life in the embrace of Northeastern PA forests, sowing the seeds for his ongoing enchantment with the natural world and its stewardship. While studying English and Music Composition at Muhlenberg College, he gravitated toward nonprofit engagement as a work study student in the college’s Office of Community Engagement. Now, at the Horn Farm Center, Andrew manages social media, develops educational programs, coordinates volunteer events, and collaborates on marketing projects, large events, and organizational capacity-building. Through all of this, he is a dedicated student of the land, with a life’s mission of learning (and providing spaces for others to learn) about bioregional ecology, regenerative agriculture, permaculture, foraging, and locally-focused ways of living in reciprocal relationship with nature.

Mel Beans

Mel is a rising junior at Franklin & Marshall College pursuing a B.A. in environmental studies and public policy. After taking an environmental justice course and diving into research on “forever chemicals,” she realized that she wanted to pursue a career that actively acknowledges and addresses the ways in which the environment is deeply interconnected with and integral to our wellbeing. She jumped on the opportunity to intern at Horn Farm Center, seeing how our mission aligns with her passions and career goals. As the Education & Communications Intern, she’s grateful to contribute to HFC’s essential role in demonstrating not only sustainable, but regenerative and resilient agriculture by assisting with research and outreach. In her free time, she enjoys being with friends and family and in nature, thrifting, listening to music, and watching video essays. On campus, she is a house advisor and the president of Catastrophic Relief Alliance, an F&M organization that addresses housing needs locally and nationally, especially in the wake of natural disasters.