The seven acres of the Evergreen campus along Sawyer Creek, the largest natural woodland within the City of Oshkosh, have been recognized as an intact Oak Savanna. A rare Midwestern ecosystem of open woodlands consisting primarily of oaks and hickories, the Oak Savanna is found between the wetter forests of the north and east, and the drier prairies further south and west.
Evergreen’s Oak Savanna is a complex, interdependent plant community in which over 40 species of native plants have already been identified. What is now seen as a beautiful and open forest was, until the late 1980’s, largely hidden and inaccessible by a dense undergrowth of invasive, non-native shrubs and plants. At that time the understory of buckthorn, often 20’ tall, was removed by the City of Oshkosh. But because of the persistent, fast-growing nature of this plant, it grew back undeterred by sporadic efforts to remove it.
This situation continued through the 1990’s until a neighbor, a retired city planner from Chicago, recognized the woods as a rare Oak Savanna. With help from Evergreen leadership, he led a successful effort to systematically restore the savanna by recruiting support from other neighbors, Evergreen residents, an area group of native landscaping enthusiasts called The Wild Ones, the Wisconsin Department of Natural Resources and the Oshkosh Parks Department.
The primary restoration task is the permanent removal of the buckthorn. Many approaches included cutting and painting the stumps with herbicide, burning with a propane torch, pulling with a weed wrench, chopping with a brush hog, and applying weed killer to leaves. All were successful to some degree. However, when carried out with persistence over several years, the results have been spectacular. Spring, summer and fall now bring an ever increasing array of wild flowers and other native plants, the seeds of which had been dormant in the shade and cool soil under the buckthorn.
The removal of the buckthorn has also made the woodland more open and accessible, and has allowed Evergreen to maintain graveled and wood chipped paths for walking or biking.
In addition to supporting a wide variety of plant life, the Oak Savanna is also home to many species of wildlife such as beaver, hawks, owls, deer, and many smaller birds and mammals.
The Evergreen Oak Savanna is an extraordinary natural resource not only for the Oshkosh area but especially for Evergreen residents, their families and the staff who can enjoy its natural beauty in our own backyard.
For more information, contact Grounds Coordinator Chris Bellin, (920) 237-2148. cbellin@EvergreenOshkosh.com