Agave tequilana planting these shoots; this has led to a considerable loss of genetic diversity in cultivated blue agave. It is rarely kept as a houseplant, but a 50-year-old blue agave in Boston grew a stalk requiring a hole in the greenhouse roof and flowered in the summer of 2006. Tequila is made only from a specific cultivar of "Agave tequilana" called 'Weber Azul'. This cultivar is larger and blue-gray in color compared to the smaller and green normal "A. tequilana". It is a rapid grower and prolific offsetter in keeping with its agricultural advantages. Tequila is produced by removing the heart
Agave parrasana and has gained the Royal Horticultural Society’s Award of Garden Merit. Agave parrasana Agave parrasana, the cabbage head agave or cabbage head century plant, is a flowering plant in the family Asparagaceae. A slow-growing evergreen succulent from North East Mexico, it produces a compact rosette of fleshy thorn-tipped grey-green leaves, 60 cm tall and wide. Occasionally mature plants produce a spectacular flower head up to 6m tall, opening red and turning yellow. This signals the death of the flowering rosette, however offsets may form and continue growing. As it can tolerate temperatures of or less, it is a popular plant