An additional 3,000 are teachers from New York City's public school system participating in professional development programs that train them to teach science courses at all grade levels.

[3]As early as 1877, ideas had been circulating in New York City to create a botanical garden; funding could not be obtained at the time, although the efforts led to parkland being set aside for future use.

[11] The stated purpose of the act was: ... for the purpose of establishing and maintaining a botanical garden and museum and arboretum therein, for the collection of and culture of plants, flowers, shrubs and trees, the advancement of botanical science and knowledge, and the prosecution of original researches therein and in kindred subjects, for affording instruction in the same, for the prosecution and exhibition of ornamental and decorative horticulture and gardening, and for the entertainment, recreation and instruction of the people.

[5]: 2 [10] The legislation would provide 250 acres (100 ha) within Bronx Park to the NYBG, and enable the board of directors to construct a library and conservatory, if at least $250,000 was raised within five years.

[5]: 2 [10] The principal officers of the new corporation set up for the garden were Cornelius Vanderbilt II, Andrew Carnegie and J.P. Morgan, with Nathaniel Lord Britton as the new secretary.

[4] Prominent civic leaders and financiers, including Vanderbilt, Carnegie, and Morgan, agreed to match the City's commitment to finance the buildings and improvements.

[13] The Board of Directors then asked landscape architect Calvert Vaux and his partner, Parks Superintendent Samuel Parsons Jr., to consult on site selection.

[19] After the city cut the NYBG's budget in 1970, the garden was forced to remain closed for 3 to 4 days a week, and officials worried that this could eventually lead to permanent closure.

That year, the NYBG announced a major renovation to the conservatory and the addition of a building dedicated to displaying plants in different habitats.

[19] The next year, budget cuts related to the 1975 New York City fiscal crisis resulted in the NYBG being closed on weekdays for the first time in its history.

Many areas were neglected, except for the 40 acres (16 ha) surrounding the conservatory, and a wetland had even been created unintentionally due to a broken sewer.

[24] The dispute continued until 2002, after several years of failed resolutions, when Montefiore Medical Center offered to move WFUV's antenna to its own facilities.

[23] In 1994 the formerly free garden started charging an admission fee to fund these improvements as well as the continued maintenance of existing facilities.

[28] The new main entrance, with a gift shop, bookstore, plaza, restrooms, cafe, and information kiosks, was completed in 2004 at a cost of $21 million.

[52] NYBG's Humanities Research Institute, supported by The Andrew W. Mellon Foundation, was created in 2014 to stimulate public discourse about humankind's relationship with nature and the environment.

[56] In February 2020, NYBG announced that it was partnering with Douglaston Development to create affordable apartments on the northwest edge of the garden.

[57] In January 2024, the NYBG revealed a major rebranding, developed in partnership with global brand consultancy Wolff Olins.

It is the largest existing remnant of the original forest which covered all of New York City before the arrival of European settlers in the 17th century.

The forest, which was never logged, contains oaks, American beeches, cherry, birch, tulip and white ash trees, some more than two centuries old.

This collection is stored in a DNA storage room with 20 freezers housing millions of specimens, including rare, endangered or extinct species.

The design was modeled after the Palm House at the Royal Botanic Garden and Joseph Paxton's Crystal Palace in Italian Renaissance style.

[80] The William & Lynda Steere Herbarium, in the International Plant Science Center behind the library,[59] is one of the largest herbaria in the world, with approximately 7.9 million specimens.

In 1895 the garden incorporated the herbarium of Columbia College, an acquisition of approximately 600,000 specimens, including the private herbaria of John Torrey and C. F. Meisner.

In 2008, Alfred P. Sloan Foundation granted the NYBG $572,000 to begin a project called TreeBOL, the Tree Barcode of Life.

Now called the School of Professional Horticulture, this fully-accredited program[88] continues to develop horticulturists of the highest caliber for positions in both public and private gardens.

[91] Beginning in 2007, the Garden added an annual fall exhibition of kiku, Japanese chrysanthemums trained to grow in modern and ancient forms.