The Heather Garden, located in a ridge west of Corbin Drive and the promenade, is described by NYC Parks as "the largest public garden with unrestricted access in New York City", with an area of . It was planned by the Olmsted Brothers as a gardenesque site with American elm trees and low-growing heather, also known as "Calluna vulgaris". The short height of the heather was intended to allow views of the Hudson River, and stone seating allowed visitors to observe the landscape. The heather took several years to grow to its full height. The Heather Garden became overgrown with invasive species after a remodeling in 1955 failed to take Olmsted's design into consideration. The garden was restored in the late 1980s following Olmsted's original plans. Minor additions and improvements continued to take place afterward. The garden contains perennials, shrubs, and trees, as well as plantings representing each season.