Century Plants (Agave L.) seem to have been planted with some regularity in the Davis area. One can be found in the On Campus Co-ops garden, in the Arboretum, and some along 2nd Street by the train tracks (the short portion of the road just east of the Amtrak station). One of a set of the plants on County Road 102 has begun to bloom, as of April 2007. These succulent evergreens are unmistakably huge — up to forty feet high in flower! The gray-green or variegated leaves are 10 to 18 inches long with long, sharp, terminal spines and shorter spines along the edges — it has a giant asparagus-like stalk about 4 inches in diameter and around 14 feet high that grows up to eight inches a day from the thick basal rosette of leaves. When the stalk reaches its full height around late spring, it begins to produce branches with brilliant yellow flowers and pollen filled cups at the ends. During the day, the flowers attract hummingbirds, moths, bees, dragonflies and wasps and at night, the pollen and musky aroma attract pollinating bats.
Members of the amaryllis family, about 200 species of Agave are recognized. Century plants take years to flower — less than a century, though it may be twenty to fifty years! Most Agave are monocarpal, which means that the plants flower just once before dying, and its flowers are hermaphroditic. However, since most Agave self-propagate by rhizomatous cloning as well as producing seed & smaller plants from the top of the stalk, there's no real danger that you won't have another once your century plant blossoms; just a few species rely solely on seed production for propagation. Century plants are supremely well adapted to Davis' hot, dry climate and thrive in dry, rocky soils.
Historically, Agave has provided various peoples with a source of soap, food, fiber, medicine and weapons. Aboriginal Australians use the stalk to make the digerie do, a musical instrument, while in Mexico the heart of the agave is used commercially as a source of tequila (Agave tequilana or agave azul), pulque & mescal. Intense commercial production of tequila in Mexico has impacted local economies and landscapes through deforestation and over-exploitation of other native species; with its extended growth cycle, Agave can impoverish soil and leave production farms exposed to erosion once harvested.
Caution: some species may produce irritant dermatitis and conjunctivitis through contact with either the leaf skin or sap.
For a listing of other plants found growing in Davis, visit our Town Flora.