Agave americana var. oaxacensis

by

The Majestic Oaxaca Century Plant: A Deep Dive into Agave americana var. oaxacensis

1. Introduction

The Agave americana var. oaxacensis, a variation of the well-known century plant, presents a unique tapestry of beauty, resilience, and cultural significance. This impressive succulent, boasting bold architectural forms and a stunning array of leaf colors, earns admiration for its ornamental value while connecting us to a rich heritage of traditional uses. From its striking rosette of fleshy leaves to its towering, once-in-a-lifetime flower stalk, the Oaxaca century plant is a testament to nature’s ingenuity. But what sets this specific variety apart? Notably, Agave americana var. oaxacensis, a beauty well-suited to drier regions, is frequently more compact and can exhibit more intense coloring in its leaves than its parent species. This makes it an ideal choice for landscaping in warmer climates.

2. Origin and Natural Habitat

As the name strongly suggests, Agave americana var. oaxacensis hails from the state of Oaxaca, Mexico. Its natural habitat centers around the southwestern regions, primarily within the mountainous and coastal areas of this vibrant state. It thrives in a diverse set of environments, including arid and semi-arid scrublands, rocky slopes, and even coastal cliffs.

The Oaxaca climate is characterized by hot, dry summers and mild winters, with an annual rainfall ranging from 500 to 800 mm, concentrated during the summer months. The soil is typically well-draining, often composed of sandy or gravelly loam with a slightly alkaline pH. The plants survive in areas exposed to intense sunlight and high temperatures. Associated plant communities include other drought-tolerant species, such as cacti, other agave varieties, and various low-growing shrubs.

3. Common Names and Etymology

While its scientific name is relatively straightforward, Agave americana var. oaxacensis, the common names reflect its geographic origin and characteristics. Commonly referred to as the "Oaxaca Century Plant" or the "Agave oaxacensis," it’s easy to see the link to where it is found. The "Century Plant" reference is the most common name reflecting the belief that Agaves bloom only once every hundred years. While not entirely accurate, as their flowering cycle usually spans multiple decades, the name alludes to the slow, deliberate growth of this remarkable plant and its grand finale in life.

The term "americana" in the scientific name denotes its association with the Americas, the geographic region of its origin, and "oaxacensis" signifies the variety’s specific origin within the state of Oaxaca in Mexico.

The historical use of Agave americana leaves as a fibre source, a raw material for ropes and textiles may have influenced it’s common names.

4. Plant Description and Characteristics

The Agave americana var. oaxacensis is a striking succulent, forming a large, symmetrical rosette that commands attention.

  • Size and Growth Habit: The plant’s mature size can reach up to 1.5-2 meters (5-6.5 feet) in height and 2-3 meters (6.5-10 feet) in width, although it tends to be a little smaller and more compact than the typical Agave americana. Its growth is slow and deliberate, with a single rosette forming a central hub from which new leaves emerge.
  • Leaf Characteristics: The leaves are lanceolate to slightly ovate, thick, fleshy, and often a vibrant blue-green color, although cultivars can produce leaves that have a more gray, bluish or sometimes a variegated look. The margins typically have prominent, reddish-brown to black spines, and the tips of the leaves are tipped with a sharp, terminal spine, both offering protection against herbivores. The leaves have a waxy coating, which aids in its drought tolerance.
  • Flower Characteristics: Like its relatives, Agave americana var. oaxacensis is monocarpic, meaning that it flowers only once in its life. After several years, perhaps decades, of growth, the plant sends up a towering, majestic flowering stalk that can reach several meters (up to 7-8 meters or 20-26 feet) in height. The stalk usually branches, creating a candelabra-like structure. The flowers are typically yellow to pale green, tubular in shape, and attract pollinators like bats, moths, and birds. Following flowering, the plant dies, leaving behind seeds as well as offsets from the base.
  • Unique Features: While similar to Agave americana, this variety tends to be more compact, and its leaves may exhibit more blue-green coloring and a slightly more architectural form. These aspects make it visually appealing especially to those looking for a striking focal point in landscapes or containers.

5. Uses

Agave americana var. oaxacensis has a range of applications both historically and in contemporary times.

  • Culinary Uses: While not as widely used culinarily as some other agave species, the heart (the core of the plant) can be roasted or baked, similar to the process used in making mezcal. The leaves, while less consumed in the Oaxaca region, are also edible. These plants are often utilized as an emergency hunger source. Caution is advised, however, as ingesting raw plant parts can cause digestive upset.
  • Fiber and Industrial Uses: Historically and today, the strong, durable fibers extracted from the leaves have been used for making rope, textiles, and other industrial products. Called ‘pita’ in some regions the material is also used to manufacture coarse fabrics and paper.
  • Medicinal Uses: Historically, certain parts of the plant have been used in traditional medicine for various purposes. It is mentioned to treat skin ailments, with leaf juce applied as a poultice for burns and wounds. The roots and leaves could be used to treat digestive problems and constipation. Scientific evidence may be limited. Disclaimer: Consulting with a qualified healthcare professional is highly recommended is you plan to consume any part of the plant.
  • Ornamental Uses: Its striking appearance and architectural form have made it a popular choice for landscaping in warmer climates. It shines as a focal point in xeriscaping, rock gardens, and Mediterranean-style landscapes.
  • Other Uses: Agaves such as this species, are becoming of growing economic and ecological significance with several applications. Besides their use to produce alcoholic beverages, the plants are also very important for conservation practices.

6. How to Grow Agave americana var. oaxacensis

Cultivating the Oaxaca century plant can be a rewarding experience, providing you adhere to the climate and geological conditions.

  • Climate and Hardiness: The plant is best suited for USDA Hardiness Zones 9-11, thriving in warm temperatures and preferring full sun exposure. It is drought-tolerant and, once established, can withstand fairly high temperatures. However, it is not very frost-hardy and requires protection from prolonged freezing.
  • Soil Requirements: Requires well-draining soil, preferably a mix of sand, gravel or perlite, and loam. It prefers a slightly alkaline pH. Heavy clay soils need to be amended to improve drainage.
  • Watering: Water deeply but infrequently, allowing the soil to dry thoroughly between waterings. Overwatering can lead to root rot. During the growing season (spring and summer), water more frequently. Reduce watering in fall and winter. Drought-tolerant once established.
  • Fertilizing: Feed sparingly in spring and early summer with a balanced, slow-release fertilizer formulated for succulents or cacti. Avoid over-fertilizing.
  • Container Growing: Suitable for container growing, especially in cooler climates. Use a large, well-draining pot and a cactus mix soil. Protect from frost during winter by bringing the plant indoors or to a sheltered location.
  • Maintenance: Minimal pruning is required. Remove any dead or damaged leaves. Clean the plant by wiping down the leaves when needed.

7. Propagation Methods

  • Offsets: The easiest method is propagation through "pups" (offsets), which are small plantlets that form at the base of the mature plant. Separate the pups carefully from the parent plant, allowing any cuts to callus over for a few days before replanting them in well-draining soil.
  • Bulbils: Some agave species, including the Agave americana lineage, might produce bulbils, which are small plantlets that grow on the flower stalk. Collect these bulbils, allow them to dry for a day or two, and then plant in well-draining soil.
  • Seeds: Collecting seeds can be tricky, and seed germination can be unpredictable. Harvest seeds from the flower stalk after the flowers have dried and the seed pods have ripened. Start seeds in a well-draining seed-starting mix.
  • Hybridisation: Agave plants are fairly easily hybridised.

8. Pests and Diseases

  • Pests: Common pests include agave snout weevils (which can cause significant damage to the plant), scale insects, mealybugs, and aphids. Control pests with regular inspection, neem oil, insecticidal soap, or other organic pest control methods.
  • Diseases: Root rot, caused by overwatering or poorly draining soil, is a common fungal disease. Prevention is key: ensure good drainage and avoid excessive watering. Other diseases can include fungal leaf spot disease. Remove affected leaves and treat with a fungicide.

9. Cultivars and Related Species

There are several cultivars and related species that are closely related to Agave americana var. oaxacensis:

  • Cultivars: While Agave americana has many named cultivars, finding cultivars specifically referencing oaxacensis is rare. Some commonly found cultivars of Agave americana with similar characteristics might include those with blue-green tints and a compact growth habit.
  • Related Species: Other agave species popular in landscaping and those with similar uses include Agave tequilana (the source of tequila), Agave angustifolia, and Agave salmiana. Additionally, many hybrids in the Agave americana family may show a similar profile.

10. Conclusion

Agave americana var. oaxacensis stands out as a remarkable plant, offering a blend of ornamental beauty. It connects us to a rich cultural legacy through its history, utility, and its presence across generations. Its architectural form, drought tolerance, and relative low maintenance make it an excellent choice for those seeking a visually stunning and resilient addition to their garden. Consider planting this majestic agave, and experience the timeless allure of the Oaxaca century plant.

Good luck and happy gardening!