Agave desmettiana, often called Smooth Agave or Dwarf Century Plant, is a favored ornamental succulent. Its elegant form and relatively soft foliage make it a graceful addition to diverse garden settings, proving less formidable than its spiny relatives. The correct spelling is desmettiana, though it is sometimes seen as demeesteriana.
Agave desmettiana Profile
Agave desmettiana forms a striking rosette of leaves. The leaves are typically a bright, often bluish-green, with a smooth texture. While some varieties may have very soft marginal teeth, the prominent, sharp terminal spine is usually short or absent.
Mature plants can reach an impressive size, with rosettes growing up to 3-5 feet tall and 4-5 feet wide. This agave is monocarpic, meaning an individual rosette flowers only once in its lifetime, typically after 8-15 years, before the flowering rosette dies. The tall flower stalk can reach 8-15 feet in height, bearing pale yellow flowers, but this event is rare in home cultivation.
Growing and Care Guide
Light Requirements
Agave desmettiana thrives in bright, indirect sunlight to full sun exposure. While it tolerates full sun, especially in cooler climates, intense, unfiltered sun in hotter desert environments may lead to leaf burn. Positioning the plant where it receives some afternoon shade can protect its foliage.
For indoor cultivation, placing the plant near a south-facing window or providing supplemental grow lights ensures adequate light. Variegated forms may lose some distinctive coloration if they do not receive enough light.
Soil and Drainage
Well-draining soil is crucial for Agave desmettiana to prevent root rot. A specialized succulent or cactus potting mix is suitable, or you can create your own by amending regular potting soil with materials like perlite, pumice, or coarse sand. This ensures excess moisture quickly escapes, preventing waterlogging.
When planting in the ground, particularly in clay soils, amend the soil with sand and rock to improve drainage. For container-grown specimens, a pot with drainage holes is essential.
Watering Needs
Agave desmettiana has low water requirements and is drought-tolerant once established. Water deeply but infrequently, allowing the soil to dry out completely between waterings. Overwatering is a common problem that can lead to root rot.
During the hotter growing seasons of spring and summer, the plant may require more frequent watering, perhaps every 2-4 weeks. In the fall and winter, during its dormant period, watering should be significantly reduced. Apply water directly to the soil and avoid getting the leaves wet, as this can promote fungal issues.
Temperature and Hardiness
This agave prefers warm temperatures, ideally between 65°F to 85°F. It is generally hardy in USDA zones 9-11, but its cold tolerance varies. While it can withstand brief periods down to 25-27°F, prolonged exposure to freezing temperatures can cause damage or kill the plant.
In regions with colder winters, grow Agave desmettiana in containers so they can be moved indoors or protected from frost. Protecting outdoor plants with a tarp during winter rains can also help prevent damage.
Fertilizing
Agave desmettiana generally does not require frequent fertilization. A balanced, diluted liquid fertilizer can be applied once a month during the active growing season in spring and summer. For outdoor plants, a light annual feeding in spring may be sufficient.
If you choose to fertilize, follow dilution instructions carefully to avoid over-fertilization. Soil in containers will deplete nutrients over time, so occasional replenishment is beneficial.
Pruning and Grooming
Pruning needs for Agave desmettiana are minimal. Remove any dead, damaged, or yellowing leaves using sharp, clean shears close to the base of the plant.
If the plant produces a flower stalk, remove it after the flowering period, as the rosette will die back. Handle the plant with care during grooming due to potential sharp leaf tips.
Propagating Agave desmettiana
The most common method for propagating Agave desmettiana is through its offsets, also known as “pups” or “suckers,” which form around the base of the mother plant. To propagate, carefully detach the offsets from the parent plant, ensuring they have some roots attached. Allow the detached pups to “harden off” or callus for a few days in a dry, shaded area before planting. This step helps prevent rot. Plant the callused offsets in a well-draining cactus or succulent mix, and water sparingly until new growth indicates establishment.
Common Issues and Solutions
Agave desmettiana is generally robust, but issues arise primarily due to improper care. Overwatering is the leading cause of problems, often resulting in root rot, a fungal disease. Signs of root rot include drooping, yellowing leaves, or black spots on the foliage. To prevent this, ensure excellent drainage and allow the soil to dry out between waterings. If caught early, removing affected parts and improving drainage may save the plant.
Pests like mealybugs and scale insects can occasionally infest the plant, appearing as white, cottony masses or small, hard bumps on the leaves. Treat these with insecticidal soap or neem oil, or by manually removing them with a cotton swab dipped in rubbing alcohol. Environmental stresses such as excessive direct sun can cause leaf burn, while insufficient light can lead to etiolation.
Landscaping Uses
Agave desmettiana is a versatile plant for various landscape designs, particularly those with a desert, Mediterranean, or contemporary aesthetic. Its upright, urn-shaped rosette and graceful, arching leaves make it an excellent focal point or accent plant.
It is well-suited for rock gardens, xeriscaping, and mass plantings. It also performs well in containers, allowing it to be enjoyed on patios or moved indoors in colder climates. Its relatively smooth margins make it suitable for areas where foot traffic is common.