During the 1930s, volunteers from local garden clubs planted seeds from native flowers along a trail in the park. This Wildflower Trail was enjoyed by many park visitors for decades. Unfortunately, many of these native plants no longer grow in the park. However, detailed records exist of the 1930 plantings.
In 1997 the National Park Service, Rutgers University and the Garden Club of America planted some of the documented native flowers along the trail, now known as the North Primrose Brook Trail. The plantings were fenced to prevent browsing. These test plots are monitored for herbivory, plant reproduction and spread.
In 1995, an Herbaceous Plant Inventory documented 320 plant species in the park, approximately two-thirds of which were native.
The park's forests still support populations of native wild flowers though in reduced numbers from a few decades ago. Jack-in-the-Pulpit is still widespread in the park, although smaller in size than has previously been found. Partridgeberry, Bird's Foot Violet, Wintergreen and Shinleaf flourish in the park. White Snakeroot, which is poisonous to mammals, has spread widely throughout the park over the last twenty years.