This grower is sure of this plant identification.
I have lots of Agave seedlings to swap or sell as these always germinate like crazy. Generally Agaves are really low maintenance, they thrive with regular watering but can survive on very little. Can go outdoors in Summer, and grow large with regular repotting if you have the space! I have never grown one to flowering in the UK but their flower stalks are very impressive. These are from a mixed species seed pack so should give a nice variety.
Agave genus (Mescal). This genus of some 136 species consists of rosette-forming, perennial succulents, which have sword-shaped, sharply toothed leaves. The smaller species will grow to 30cm high and flower only after 5-10 years. The taller species will grow to 5m high and may take 20-40 years to flower. Agave have lived on Earth for some 60 million years.
Most of the species have hard, blue-grey leaves that are half hardy, whilst the grey-green or green leaved species are usually frost tender, min 5C. Grow them in full sun with well drained soil. In their native habitat, Agave will survive hot deserts and dry, sunny mountain sides.
Agave tequilana is pulped and fermented, turning the sugars into alcohol, to create the Mexican drink Tequila. Agave sisalana, or sisal, is made from the leaf fibres of the plant. Uses include strong, sunlight resistant rugs and carpets, cords, sandals and baskets.