Yours, Etc.: Origins and Uses of 8 Sign-Offs
c.1300, from Old North French gardin (13c., Modern French jardin), from Vulgar Latin hortus gardinus "enclosed garden," via Frankish *gardo, from Proto-Germanic *gardaz- (cf. Old Frisian garda, Old Saxon gardo, Old High German garto, German Garten "garden," Old English geard "enclosure," see yard (n.1)). Italian giardino, Spanish jardin are from French.
Garden-party is by 1843. Garden variety in figurative sense first recorded 1928. To lead someone up the garden path "entice, deceive" is attested by 1925.