By: John Holback, Stewardship Manager

One of our recent initiatives at Willistown Conservation Trust was the establishment of a small native plant nursery, designed to support our restoration projects and promote local biodiversity. Having our own nursery allows us to preserve the genetic diversity of local native plants through seed collection and propagation while saving a little money from purchasing plants (a small, yet significant benefit). Additionally, the nursery provides new and fun tasks for volunteers, who helped tremendously with construction, maintenance, and eventual planting. Being able to see the whole cycle – harvesting and sowing seeds, watching them sprout, caring for the plants, and finally planting them – is quite a rewarding experience for volunteers and staff alike. “Running” a nursery also served as a learning opportunity for staff who had to decide what plants to grow, how to grow them, how to propagate collected seeds, and how to deal with the impacts of environmental stressors like pests and drought.

This past winter, several volunteers came out to help construct our nursery tables with lumber that Beatty Lumber & Millwork Company generously donated. Four tables were built to accommodate about 3,000 small plugs (narrow but deep cone-shaped tubes allowing herbaceous plant root growth) and 600 small trees and shrubs. In late April two groups of students – one from Delaware County Friends School and one from The Episcopal Academy – came out to help fill the individual plugs and tree containers with potting mix, which they mixed by hand with sand for better drainage and root development. In May, staff planted each of the 3,000 plugs with native grass and forb seeds. Several species were planted including Indiangrass, Little blue-stem, Butterfly Weed, and Buttonbush. Between June and July, we had 2,500 seeds germinate into vigorous seedlings.

By August, the heat and dry weather began roasting the still small and vulnerable plants. It became difficult to keep up an effective watering schedule and some of the seedlings did not survive. A shade cloth was installed halfway through the summer to keep further sun damage to a minimum. Thankfully, the seedlings didn’t have long to wait, as September was our target planting month. Throughout several volunteer events, 1,500 seedlings were planted and watered in. The hard, dry ground made digging very difficult so a variety of hole-digging methods were tested. What worked best was using a small auger on a corded drill to dig the 2” wide holes necessary for the plugs. All of the grass seedlings were planted in Kirkwood Preserve and many of the perennial flowers were planted at the Rushton Conservation Center and in the meadow at our main office. 

In October, we collected acorns, viburnum fruits, persimmons, and buckeyes to grow in the tree containers. A previous group of volunteers from the Young Men’s Service League, collected and planted close to a hundred White Oak acorns which will germinate and grow outdoors this winter and be planted next fall. Once the rest of the tree containers are planted, we can put the nursery to sleep for the winter. In the early spring, we will repeat the process, making changes where necessary, in anticipation of another successful and fun year of growing our own native plants.

By John Holback, Stewardship Manager

In early 2024, Willistown Conservation Trust purchased a 90-acre parcel of land between Plumsock Road and Providence Road – the soon to open, Kestrel Hill Preserve. Mostly open rolling hills, the land had been a passively managed wildland with the exception of 25 acres of agricultural fields. The empty, mostly weed free agricultural fields offered the unique opportunity for WCT to convert the land to a more ecologically valuable resource and with minimal effort.

Historically, open spaces in our region were created and maintained by fire, caused either by lighting, or by indigenous peoples who used fire to manage the land.Before that, megafauna like mammoths, ground sloths, and others cleared the landscape through their activities. Nowadays, most grasslands and meadows have an agricultural past and are usually dominated by non native, cool-season grasses that were planted and used for animal fodder. Without regular disturbance (fire, mowing) these grasslands quickly fill in with woody cover (trees, shrubs) and no longer serve the species that have adapted to rely on them. And without active management, for example, establishing native grassland plants and removing non-native ones, they will remain relatively low-quality ecosystems, dominated by non-native grasses.

Establishing a native grassland usually starts with removing undesirable plant species and then planting desirable ones. Modern no-till-drills, a type of agricultural equipment, allow land managers to plant lots of seed over large areas quickly and with minimal soil disturbance. Planting this way ensures the seeds have good soil contact, minimizes erosion, and hides the seed from hungry birds and small mammals. Since the agricultural fields at Kestrel Hill were already free of plants, WCT opted to rent a no-till-drill to seed the two former agricultural fields.

Two different seed mixes were planted: one contained native grasses and forbs (flowering plants;) the other included native grasses and a cover crop of oats. The cover crop’s purpose is to hold the soil in place, help prevent establishment of undesirable plants, and provide cover for the native seedlings. The 10-acre field adjacent to Providence Road features three native grasses and 24 different forbs while the 15-acre field adjacent to Plumsock Road features four native grasses. Over the next few years, both areas will require regular mowing and spot treatments to prevent undesirable plants from establishing, while allowing the native plants to get established and begin spreading.

Establishing grasslands does more than simply aid displaced plant and animal species. Grasslands sequester large amounts of carbon, helping to cool a rapidly warming planet. They build soil health, and absorb excess stormwater. Healthy grasslands require little maintenance – only annual mowing or burning every few years, and some small spot treatments for non-native weeds. Soon visitors will be able to enjoy the recreational offerings of WCT’s new grassland preserve. Hiking and equestrian trails and scenic vistas will improve as the native plants grow and thrive.

By Lauren McGrath, Director of the Watershed Protection Program, and Susan Lea, Darby and Cobbs Creek Community Science Volunteer

In 1919, naturalist and zoologist Arnold Ortmann, in connection with his taxonomic studies of freshwater mussels (Unionidae), recorded approximately eight species of mussels in Darby Creek. As of a decade ago, surveys of more than sixty stream reaches in Southeastern Pennsylvania yielded only about six relic populations of the eastern elliptio (Elliptio complanata). Freshwater mussels are the most at-risk animal group in the United States due to pollutants and poor water quality, habitat loss, and barriers to host fish. Yet, the eastern elliptio remains a common mussel in the tri-state area and has been previously identified by the Willistown Conservation Trust (WCT) Watershed Protection Program Team within the headwaters of Crum and Ridley Creeks. However, among the local scientific community, it was believed that historic pollutants had eradicated freshwater mussel populations in Darby Creek; discovering a mussel shell was merely an artifact of what once was. That is, until now.

The Darby and Cobbs Creek Community Science Monitoring Program (DCCCS), a collaborative project among WCT, Darby Creek Valley Association (DCVA), and Stroud Water Research Center, was established in the spring of 2021. Since the fall of 2021, a DCCCS volunteer has monitored two sites in the Darby Creek headwaters in Berwyn, about 275 yards apart and bifurcated by an unnamed tributary. After noting several mussel shells in the stream (eastern elliptios can live up to 80 years), the volunteer discovered a small mussel bed of about a dozen live eastern elliptio mussels in 2022. The following summer with the assistance of staff from WCT and DCVA, several more eastern elliptio beds, with mussels numbering over one hundred, were identified between the two sites. Curiously, the mussel beds seemed to stop downstream from where the unnamed tributary entered Darby Creek even though their preferred sandy substrate continued further down the waterway.

Equipped with this discovery, curiosity about the impact of these amazing bivalves on the watershed, and innumerable questions, DCCCS reached out to Dr. Erik Silldorff, Restoration Director & Senior Scientist at Delaware Riverkeeper Network, who agreed to lead the survey effort in Darby Creek to gain a better understanding of the health of this special mussel bed. Dr. Silldorff has years of experience conducting mussel surveys in the Delaware River watershed and was enthusiastic about sharing his knowledge and training a new cohort of mussel advocates on identification and survey techniques.

On a balmy morning in late May, the team of mussel enthusiasts came together: staff from WCT, DCVA, and Brandywine Conservancy; students from Drexel University and Oberlin College, high school students, residents, educators, and township officials eager to learn more about these fascinating stream residents. All gathered together to learn how to discern the difference between common species of mussels based on their shell morphology and to learn more from Dr. Silldorff about the fascinating biology and ecological decline of mussels in the Delaware Watershed.

After two days of careful inspection of the stream bed through goggles and snorkels and using clear-bottomed trays, over 850 mussels were documented in Darby Creek, a population large enough to be a remnant that survived the colonization of North America. The majority of mussels found were eastern elliptio, but to the delight of all, two live Alewife floater mussels (Utterbackiana implicata) were also found in the waterway. Alewife floaters use a broad variety of habitats, including ponds and lakes, as well as streams, rivers, and tidewaters; their presence in Darby Creek suggests that there may be additional populations somewhere upstream.

Truly the most exciting discovery of the survey was two juvenile mussels, less than one inch long, that were found perched on the edge of two separate fish nests. Juvenile mussels bury themselves in the sediment and are difficult to find without the use of specialized survey techniques. Fate and fish worked with the survey team as the nest-building fish had excavated the young mussels in time to be found and documented.

Curiously, there were fewer mussels downstream of the unnamed tributary, and no mussels within the tributary. These observations line up with three years of water quality data collected by DCCCS volunteers at sample sites upstream, on, and downstream of the unnamed tributary (see map). The upstream site has better water quality than the downstream site, and the site on the unnamed tributary has the poorest water quality of all. This suggests water conditions in the unnamed tributary are negatively impacting the mussel population. Further investigation is needed to understand this pattern and ensure this historic mussel population continues to thrive for generations to come.

Freshwater mussels are generally considered inedible, yet they are top-tier bioindicators of water quality, as they are sensitive to pollutants, including road salt, and water temperature. They are also integral to healthy stream ecosystems. Despite Darby Creek’s status as an impaired watershed, the presence of these amazing organisms tells an important story about the resilience of natural systems. However, this resilience cannot be taken for granted, and further research is needed to understand why this population disappears below the unnamed tributary and why there are no additional mussel beds as the stream flows further downstream. Protecting these most delicate and sensitive stream creatures translates into safer, healthier water for all residents who live in and alongside Darby Creek.

Chanticleer Joins the Darby and Cobbs Creek Community Science Program

The Darby and Cobbs Creek Community Science Program (DCCCS) is a collaborative research project between the Darby Creek Valley Association and WCT’s Watershed Protection Program.

In May, Chanticleer became the first public garden to join the program as a community science sample site, with garden staff monitoring the health of Bell’s Run as it flows through 50 acres of Chanticleer’s property, 35 acres of which are open to the public. The garden is a study of textures and forms, where foliage trumps flowers, the gardeners lead the design, and even the drinking fountains are sculptural. It is a garden of pleasure and learning, relaxing yet filled with ideas to take home. Visit chanticleergarden.org to learn more.

Chanticleer strives to reduce its environmental impact. Solar panels produce 20% of their electricity. Cisterns capture 50,000 gallons of rainwater for irrigation, storm water basins help recharge groundwater, and most paths are permeable. Integrated pest management keeps plants healthy and promotes a strong population of insects. Meadows, sedges, ferns, and other lawn alternatives replace some turf. Since 1990, gardeners have planted hundreds of trees at the garden and along local streets in Wayne.

The addition of Chanticleer as a sampling location for the DCCCS Program was facilitated by volunteer turned WCT Director of Community Engagement, Gretchen Groebel, who has had the pleasure of collaborating with the garden in the past on meaningful environmental programming focused on backyard habitat. DCCCS volunteers, including those at Chanticleer, visit their sites once per month to measure key water quality indicators. Frequent monitoring at sites throughout the watershed enables the identification of healthy areas that should be protected and areas in need of restoration.

The Darby and Cobbs Creek Community Science Program has 33 sample sites, monitored monthly by over 40 volunteers, on Darby Creek and its tributaries, including Cobbs Creek. You might notice an extra “C” in our name. We recently added “Cobbs” to our name to reflect the importance of the largest tributary of Darby Creek. Visit darbycreekcommunityscience.com to learn more about the program and explore our results.

Another successful initiative takes root
at Kestrel Hill Preserve

What can be done to protect beautiful but rapidly disappearing wilderness, vulnerable wildlife, and precious natural resources? Willistown Conservation Trust (WCT) offers a myriad of practical solutions.

For over 30 years, WCT’s expert staff, dedicated volunteers, and private landowners have worked strategically to conserve thousands of acres in southeastern Pennsylvania through a comprehensive program including carefully-curated conservation easements and public nature preserves.

Last year, WCT’s team mobilized quickly and implemented a plan to save a 220+/- acre farm that was listed for sale. First, WCT partnered with a concerned neighbor who purchased the property to pre-empt development. Next, permanent deed restrictions were placed on 130+/- acres, restricting future development. Finally, WCT entered into an agreement to acquire the remaining 90+/- acres and establish a new public nature preserve.

WCT’s fifth public nature preserve, Kestrel Hill Preserve is situated at the heart of over 7,500 conserved acres that extend across Chester and Delaware counties. The Preserve is named in honor of the American Kestrel, a small, colorful falcon that thrives in expansive grasslands. Kestrel populations are declining throughout North America due to habitat loss, but breeding kestrels near Kestrel Hill Preserve and at WCT’s nearby Kirkwood Preserve, indicating that our open space, habitat, and bird conservation programs are taking flight.

To date, an enthusiastic group of supporters have contributed $6.7 million towards the $12.5 million cost to acquire and open Kestrel Hill Preserve. Now, we need your help to: complete the acquisition, establish public access and parking; clear hiking and equestrian trails; restore agricultural fields and wetlands to native habitat; and support wildlife and the watershed that connects to our region’s water supply.

Instead of 40 new homes, idyllic Kestrel Hill Preserve will open soon for you to enjoy, with rolling hills including a 160’ elevation drop; lush meadows; mature woodlands; freshwater streams; miles of peaceful trails; 85 species (and counting!) of native and migrating birds, and an internationally-recognized “Important Bird Area.” The Preserve will operate 365 days a year, from dawn to dusk–and 24 hours a day for wildlife! – in perpetuity, no less!

Can we count on your help to secure this spectacular Preserve, build new homes for wildlife, and protect the critical watershed?