1670s, "cultivation of a garden," coined from Latin hortus "garden" (from PIE root *gher- (1) "to grasp, enclose"), probably on model of agriculture. Famously punned upon by Dorothy Parker.
Entries linking to horticulture
*gher- 1
Proto-Indo-European root meaning "to grasp, enclose."
It forms all or part of: Asgard; carol; choir; choral; chorale; choric; chorister; chorus; cohort; cortege; court; courteous; courtesan; courtesy; courtier; curtilage; curtsy; garden; garth; gird; girdle; girt; girth; -grad; hangar; Hilda; Hildegard; Hortense; horticulture; jardiniere; kindergarten; Midgard; orchard; Terpsichore; Utgard; yard (n.1) "patch of ground around a house."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ghra- "house;" Albanian garth "hedge;" Greek khortos "pasture;" Phrygian -gordum "town;" Latin hortus "garden;" Old Irish gort "field," Breton garz "enclosure, garden;" Old English gyrdan "to gird," geard "fenced enclosure, garden," German Garten "garden." Lithuanian gardas "pen, enclosure," Old Church Slavonic gradu "town, city," and Russian gorod, -grad "town, city" belong to this group, but linguists dispute whether they are independent developments or borrowings from Germanic.
agriculture n.
mid-15c., "tillage, cultivation of large areas of land to provide food," from Late Latin agricultura "cultivation of the land," a contraction of agri cultura "cultivation of land," from agri, genitive of ager "a field" (from PIE root *agro- "field") + cultura "cultivation" (see culture (n.)). In Old English, the idea could be expressed by eorðtilþ.