To prevent salt from ascending from the underground to ruin the vegetation, the vineyards are being irrigated several weeks every spring. By the end of the 19th century when de French vineyards were destroyed by the wine louse Phylloxera, the wine growers in the lagoon discovered that the wine louse couldn't survive these yearly enforced baths. This discovery means that Ferrandiere, because of it's position, only uses genuine, old French vines, and is consequently not forced to graft the French sorts on American roots as done elsewhere in France.