The Collaborative International Dictionary of English v.0.48:
Horticulturist \Hor`ti*cul"tur*ist\, n. One who practices horticulture. [1913 Webster]WordNet (r) 3.0 (2006):
horticulturist n 1: an expert in the science of cultivating plants (fruit or flowers or vegetables or ornamental plants) [syn: horticulturist, plantsman]