University greenhouses power the flowers in Princeton's gardens Share on Facebook Share on Twitter Share on LinkedIn Email Print By Danielle Alio, Office of Communications on Aug. 31, 2015, noon Featured Video: University greenhouses power the flowers in Princeton's gardensPlay video: This video shows the Princeton University greenhouses this spring as annual flowers bloomed before being planted on campus for the summer and fall. About 6,000 annuals were grown this year.