Scholars agree that this surname derives from Greek and is linked to horticultural activity. E. De Felice traces it to the Calabrian nickname and occupational name laganà or lacanà, characteristic of the modern Greek-speaking, or grika, areas of Calabria, itself derived from the Greek lachanas ("market gardener, grower and seller of vegetables"), a form connected to lachanon ("greens, vegetables"). G. Rohlfs specifies the etymon as the vulgar Greek λαχανᾶς ("vegetable seller, greengrocer") and notes that in Greece the form Lachanàs survives as a surname. P. Durante agrees with this Greek root and glosses it as "grower of vegetables," while G. P. Holmes defines it succinctly as "greengrocer," of Late Greek origin. It is also noted that this is an occupational surname derived from the Greek dialects spoken in southern Italy, particularly in Calabria, and that surnames of this origin frequently carry a stress accent on the final vowel.

The geographical distribution of the surname is concentrated mainly in Calabria. Rohlfs documents its presence in the cities of Cosenza, Catanzaro, and Reggio Calabria, as well as in localities within their provinces: Briatico, San Vito, Bovalino, Siderno, and the Gioia Tauro area. Rohlfs further notes that the surname accounts for the place name of the municipality of Laganadi. De Felice stresses that it is the second most frequent surname in Reggio Calabria.

E. Rossoni supplies historical documentation, recording the surname in Reggio Calabria from the first half of the seventeenth century: the notary Livio Laganà, who on May 3, 1640, drew up the deed of possession of the Barony of Sambatello by the city of Reggio. Rossoni further distinguishes formal variants: Lagana (without the accent), proper to Reggio Calabria; Laganà, the most widespread form, also from Reggio Calabria but with a significant presence in eastern Sicily and throughout the rest of Calabria; and Laganara, an extremely rare form that would appear to originate in Apulia.