This native of Mexico, and southeastern United States is a tender evergreen perennial or shrub. Large sword-like leaves form a basal rosette to six feet tall. The leaves are gray green to blue green, and up to six feet long by ten inches wide with sharp spines on the sides and tip. The terminal spine can be an inch long and capable of inflicting serious injury to man or cattle. The leaves are often embellished with white or yellow markings that distinguish different varieties and cultivars and older leaves often curl downward in an attractive way. The branched flowering stalks rise up to forty feet tall and bear a mass of white to yellowish-green flowers three to four inches long. The plant blooms once in the summer when it is about ten years old in warm climates, up to thirty years in cold climate, and then dies. Offsets are produced to carry on, however, so continuity in ensured. Century plant is heat tolerant and an excellent choice for xeric sites. It can be used a fence or impenetrable hedge, and grown in containers.
Type: Evergreen tender perennial
Bloom: Tall spikes of yellowish green flowers 3-4” long are produced on branched stems up to 40’ tall in summer.
Size: 6-40’ H x 5’ W
Light: Full sun
Soil: Average, light, sandy or gravely, very well drained
Hardiness: Zones 9-11
Care: Remove lower leaves as they die avoiding injury from spines. Potted plants need yearly application of low nitrogen high phosphorus fertilizer.
Pests and Diseases: None of significance
Propagation: Offsets, seed
Companion plants: Knifeleaf acacia, Artemisia ‘Powis Castle’, orange California poppies, blue fescue, Leucadendron, sea lavender (limonium)
Outstanding Selections:
Agave americana var. marginata (arching or curled leaves with white or yellow stripes along margins)
Agave americana var. variegate (like above but with very thin marginal stripes)
Agave americana var. medio picta (stiff upright leaves with wide yellow central stripe; medium sized plant)
Agave americana var. medio-picta ‘Alba’ (short,slightly arching leaves with wide grayish white central strip; striped flower stalk on relatively small plant)
Agave americana var. striata (Gray green usually upright leaves with thin yellow streaking; medium sized plant).
Karen Meyers