Agave weberi aka Weber's Century Plant

Agave weberi, or Weber agave, is a perennial succulent from Mexico. It belongs to the asparagus family, Asparagaceae. Kew lists its native range as San Luis Potosí and Tamaulipas. LLIFLE also lists Coahuila, Nuevo León, and Durango. It grows in desert and dry shrubland habitats. Many plants in gardens appear to be horticultural clones.

The plant forms a single rosette or branches into more. Small offsets also grow around its base. Garden rosettes stand about 5–6 feet [1.5–1.8 metres] tall. Their width may match their height or reach 10 feet [3 metres]. The plant has no clear stem beneath its leaves. Removing the lower leaves can expose a short trunk. Its broad, open shape gives it value as a garden accent.

The thick leaves range from grey-green to blue-green or pale blue-grey. They may grow straight or bend outward and down. Most reach about 4 feet [1.2 metres] long. Some reach 6.6 feet [2 metres]. Each leaf widens near its middle, then narrows to a point. The upper face is flat or slightly hollow. Leaf edges have few teeth, but sharp spines still pose a handling risk. The fleshy leaves are also fragile.

Yellow flowers grow in clusters on a tall stalk. This stalk reaches about 15–20 feet [4.5–6 metres]. Flowering falls between spring and summer. Each rosette flowers once, then dies. Capsules hold flat, disc-shaped seeds. Plants take several years to reach full size. LLIFLE describes growth as moderate in one section and slow in another.

Grow this agave in porous soil that drains well. It needs full sun, though strong summer heat can make its leaves close inward. Full sun helps keep the plant compact and its leaves blue-grey. Water well once the soil feels dry. Give extra water during the hottest part of the year. Winter watering can fall to once every month or two. It withstands heat and drought well. LLIFLE calls it cold hardy but gives no temperature limit. Care mainly involves removing old leaves. Grow new plants from seed or basal offsets. Let cut offsets dry for several days before potting them. Pots and landscape beds both suit this species. Its foliage supplies colour through the year. The species also has a traditional use in making mezcal, rather than tequila.