The Thielke Arboretum of Glen Rock is located on Doremus Avenue and is accessible though the path at approximately 412 Doremus Avenue, with parking on the street. Alternately, the Arboretum can be reached via the west end of the Municipal Pool parking lot. The park is open from dawn to dusk, seven days a week.

The Thielke Arboretum of Glen Rock is a wetland forest with perennial, shade, azalea and grass gardens, lawns, and an allee of Kousa dogwood trees. There is a spring fed pond with fountain and aerators that is stocked annually with fish. A section of the arboretum, across Diamond Brook is a bird sanctuary.  The Arboretum, with its antique Gazebo surrounded by engraved brick pavers and four small gardens, is a popular site for special celebrations.

Many adults and children, as well as classes from pre-school through high school, visit the Arboretum throughout the year to study various aspects of horticulture.

The borough purchased the land on Doremus Avenue on August 26, 1954 for $44,000. Dr. Fred W. Morris, who was an amateur arborist, originally owned the property, which was almost eleven acres in size. The area was declared a municipal park in 1959 and because of the wide variety of tree species was dedicated on May 19, 1963 as "Glen Rock Arboretum.” Friends of the Glen Rock Arboretum, Inc. is a volunteer organization dedicated to the preservation, maintenance and development of the arboretum. 

The park is open from dawn to dusk, seven days a week.  Parking is available at the pool parking lot and on the west side of Doremus Avenue.  The Gazebo may be reserved for special functions by completing an application at Borough Hall during business hours; for more information call (201) 670 – 3956.  Adherence to the policy of "Carry in, Carry out" is requested, as it is in all borough parks.

For more information about the Theilke Arboretum, visit https://www.thielkearboretum.org/.