late 13c. (late 12c. in surnames), from Old North French gardin "(kitchen) garden; orchard; palace grounds" (Old French jardin, 13c., Modern French jardin), from Vulgar Latin *hortus gardinus "enclosed garden," via Frankish *gardo or some other Germanic source, from Proto-Germanic *gardan- (source also of Old Frisian garda, Old Saxon gardo, Old High German garto, German Garten "a garden," Old English geard, Gothic gards "enclosure"), from PIE root *gher- (1) "to grasp, enclose." Italian giardino, Spanish jardin are from French.
As an adjective from c. 1600. Garden-party "company attending an entertainment on the lawn or garden of a private house" is by 1843. Garden-variety in figurative sense first recorded 1928. To lead someone up the garden path "entice, deceive" is attested by 1925. Garden-glass "round dark glass reflective globe (about a foot and a half across) placed on a pedestal, used as a garden ornament," is from 1842.