The tequila cactus or the common name Blue Agave plant (Agave tequilana) needs high altitude and lots of sun to flourish. It is only hardy in USDA zones 9b and 10. The Blue Agave plants are a stunning plant that can reach a height and width of eight feet.When mature, this monocarpic plant sends out a fifteen-foot high, edible asparagus-like flower stalk and produces large numbers of pups at its base.