was it a school as well?
Yes
Briarcliff Farms
In September 1900, Law and the committee established the School of Practical Agriculture and Horticulture as part of Briarcliff Farms, on an elevated site about midway between the Briarcliff Manor and Pleasantville train stations on Pleasantville Road.
what is briarcliff farms? It was a farm. where was it located? Briarcliff Manor, Westchester County, New York. did it have any greenhouses? Yes why were they used? To produce American Beauty rose and rare carnations.
wiki:20075254
Briarcliff Farms [SEP] School of Practical Agriculture
Dodge. Its board of trustees had five officers (with Theodore L. Van Norden president) and seventeen other trustees, including Law, V. Everit Macy and James Speyer. George T. Powell, a "recognized authority on scientific agriculture" according to "The New York Times", was consulted; he later organized the school and became its director. When Walter Law was included the school took shape, since he provided its land and building. In September 1900, Law and the committee established the School of Practical Agriculture and Horticulture as part of Briarcliff Farms, on an elevated site about midway between the Briarcliff Manor and Pleasantville train stations on Pleasantville Road.