Agave parrasana

Botanical Name — Agave parrasana

Common Name — Cabbage Head Agave

Plant Family — Asparagaceae

Background

Agave parrasana is a compact species, growing up to one foot tall and wide. Short, broad, blue-green tinted leaves form a tight, spherical rosette. The highly elevated mountain tops of northeastern Mexico are home to this agave. This species tends to grow as a solitary rosette. In its lifetime plants will produce few offsets, if any. This species has the unique habit of beginning to put out a flower stalk in summer, then pausing in the fall with the stalk partially up, leaving a clump of thick bracts clustered at the tip to protect the developing flowers inside. After waiting out the winter, it continues growth in spring. Floral branches eventually emerge from the stalk, which can reach up to 12 feet in height, terminating in a cluster of red flowers which turn yellow as they open. The flowering completes nearly a year after the process began.

Growth Requirements

Sun

• Agave parrasana prefers full sun, ideally 5-8 hours a day. In extremely hot areas they will appreciate some shade.
• Plants should be acclimatized when being moved from full shade to full sun or indoors to outdoors.

Temperature/ Humidity 

• Cabbage head agave plants are very heat tolerant, thriving in temperatures above 75°F.
• The ideal minimum temperature is 50°F but this species can tolerate temps as low as 15°F.

Water

• Agave parrasana are drought tolerant, but will thrive when watered regularly during the summer. 
• Allow soil to dry out fully between waterings, then water thoroughly. 

Soil/Roots

• Agave plants prefer gritty, well drained soil. Use a mix formulated for cacti or succulents or amend regular soil with up to 50% pumice or sand to improve drainage.

Flowering

• These agaves will flower once they reach maturity, which can take up 25 years. They will send up a flower stalk up to six meters tall. Red or purple buds that open to yellow will cluster on branches that form at the end of the stalk.
• Bloom season is during the summer, from June to October. The entire flowering processes can take up to a year since the flowering process begins in summer, pauses during winter, and completes the following summer. 
• Agave parrasana are monocarpic, meaning rosettes will flower once and then die.

Fertilization

• These plants don’t need to be fertilized regularly. You can fertilize with a balanced fertilizer diluted to half strength or cacti or succulent fertilizer once during the growing season to refresh soil. 

Propagation

• Agave can be propagated by separating pups, however this species produces very few offsets so it is generally easiest to propagate by seed.
• Seeds can be collected from flowering plants. Allow pods to dry and break open to collect seeds. 

Health

Diseases

• When grown outdoors these can be susceptible to agave snout weevil.
• They can also be prone to Phytophthora fungus under damp, poorly drained soil conditions.

Maintenance (pruning, legginess, repotting)

• Agave are slow growing and only need to be repotted once every 2-3 years. Repot in shallow pots using a well drained mix. Take great care when repotting cacti. Spines are extremely sharp and flesh and skin contains a poisonous sap that can irritate skin.

Toxicity

• Many agave produce a sap that is highly irritant to skin and soft tissues if ingested. Specific details on this plant are not well document but as a measure of safety, plant should be kept out of reach of children and pets. Leaves are also covered in sharp spines that can wound a child or pet.

Photo Credit

Dr. Hans-Günter Wagner