Common Name: century plant
Type: Herbaceous perennial
Family: Asparagaceae
Native Range: Texas
Zone: 7 to 10
Height: 2.00 to 3.00 feet
Spread: 3.00 to 4.00 feet
Bloom Time: June to August
Bloom Description: Yellow
Sun: Full sun to part shade
Water: Dry
Maintenance: Low
Flower: Showy
Attracts: Birds, Hummingbirds, Butterflies
Other: Thorns
Tolerate: Deer, Drought, Dry Soil, Shallow-Rocky Soil
Culture
Reliably winter hardy to USDA Zones 7-10. Best growth occurs in a sandy/gritty, dry to dry-medium moisture, well-drained soil in full sun. Tolerates some light shade. Sharp soil drainage is important. Poorly-drained soils inevitably lead to root rot. Tolerates dry soils and drought. Surprisingly good winter hardiness for this succulent. Plants have reportedly survived winters with temperatures as low as -20F (USDA Zone 5), but cold temperatures should be "dry cold" as opposed to "wet cold".
Noteworthy Characteristics
Agave havardiana, often called Havard's agave or Havard's century plant, is a rosette-forming succulent that is native to rocky outcrops and grasslands of the Chihuahuan Desert of western Texas and northern Mexico, specifically the Chisos Mountains and Davis Mountains of the Big Bend region. This plant is typically found at elevations from 4,000 to 6,000 feet. It is most noted for its attractive blue-gray evergreen leaves, but is also noted for its infrequent but spectacular flowering spikes. Thick, rigid, smooth, blue-gray leaves (to 24” long) form a large, dense, symmetrical, basal rosette. A rosette will typically mature over time to 2' tall by 3' wide. Each leaf has dark brown, curved spines along the margin and a sharp terminal spine. This species is usually solitary, but mature specimens may occasionally produce offsets. Each rosette will flower only once, usually at some point between 20-40 years. One huge flowering stalk (to 12' tall) will rise from each rosette, with each stalk producing 12 to 20 side branches, and each side branch sporting large clusters of yellow flowers. In its native habitat, flowers typically bloom in summer (June - August).
The genus name Agave comes from the Greek word agauos meaning "admirable" or "noble" in probable reference to the very tall flower spikes found on the plants of many species of Agave.
Named in honor of Valery Havard (1846-1927), a French-born army officer, physician, author, and botanist who studied the flora of Texas in the early 1880s.
Problems
No serious insect or disease problems reported.
Uses
Rock gardens, urban gardens, succulent gardens and xeriscapes. This plant can also be grown in a container with well-draining soil if provided protection from winter moisture.