Agave A-go-go

by | May 1, 2009 | Native Plants

ON A MISTY, GRAY MORNING, third-generation master distiller Carlos Camarena drives his pickup down the muddy, pothole-pocked road past row upon row of blue-tinged Agave tequilana. The blue agaves thrive in the deep red soil of the Los Altos region in the Mexican state of Jalisco. En route from the distillery to La Alteña headquarters, Camarena talks about agaves, tequila production and what sets his family’s distillery – and its El Tesoro label – apart from the rest. Camarena is an agronomist by training and articulates the importance of preserving tradition, quality product and ecological balance.

Agaves are known for their versatility, and tequila is arguably the best-known product made from agaves – specifically blue agaves. Tequila production, once considered a cottage industry, is now big business. La Cámara Nacional de la Industria Tequilera – The Mexican National Chamber of Commerce for the Tequila Industry – reports that more than 284 million liters of tequila were exported to the U.S. in 2007. The $1 billion U.S. market is the largest outside of Mexico.

Unfortunately, tequila’s popularity led many growers to increase agave production with augmented – and sometimes detrimental – techniques. Farmers seeking more lucrative crops lost much of agave’s genetic diversity by planting only the more marketable A. tequilana instead of the varied agaves once used to produce tequila and other beverages. In some cases, heirloom varieties have been completely wiped out. Lack of diversity and modern production techniques are believed to have caused the bacterial and fungal infestations that decimated entire agave fields beginning in the late 1980s.

A handful of producers, like Camarena and his family, work to restore nature’s gentle balance with traditional methods from the ground up. “El Tesoro is about quality … For that reason, after 70 years, the factory continues to produce a traditional artisanal product … It is ‘rústica tradicional.’ That is, quality is not sacrificed for quantity,” Camarena explains.

Camarena says that one way La Alteña maintains high standards is by growing its own agaves without synthetic herbicides or pesticides. La Alteña relies on organic materials for fertilizer, and agave crops are rotated with corn and beans to balance the soil – even though in some years subsistence crops can be worth far less than a field of agaves. As Camarena sees the relationship between humans and the land, “Tú me das – yo me doy. You give to me – I give to you.”

Evidence links agaves to the Mesoamerican human diet since approximately 7000 B.C. The plant’s leaves, stalk, flowers and nectar provided a significant source of nourishment, fiber and shelter. Liquid extracted from plants, such as the Agave salmiana, was turned into nectars and syrups and fermented to become the lightly alcoholic beverage “pulque.” Many of the historic plant uses are still employed today. For example, agave nectar sweetening products made from numerous plant types – including A. tequilana and A. salmiana – are gaining in popularity. The sweeteners have a low glycemic index, are sweeter than white sugar and can dissolve in cold liquids, unlike honey. The nectar purportedly contains traces of minerals, amino acids and vitamins.

Other agave products include housing material, belts, sandals, nets, bags, basketry, mats, paper, blankets, clothing, brushes, needle and thread, fish stringers, musical instruments, and soap. Like tequila, agave’s fiber products have modern economic importance. For example, sisal from Agave sisalana is used to make rope and twine. Higher-quality sisal is sought after for rugs and carpeting, and lower quality fibers are made into items such as paper products and dartboards. Sisal most likely originated in what is now the Mexican state of Chiapas, and henequen – another fiber from the Agave fourcroydes that’s used for rope, twine and textiles – is still largely grown in Mexico.

Agaves are native to the western hemisphere and found throughout North and Central America. Central Mexico serves as the center of agave distribution, with a northward range including California, Nevada, Utah, Arizona, New Mexico and Texas. “In total, there are close to 200 naturally occurring species and subspecies, not counting the numerous hybrids, both natural and man-influenced,” says Chad Davis, curator of agaves at the Desert Botanical Garden in Phoenix.

The plants grow from sea level to more than 7,000 feet in seashore, desert, arid plains, dry hillsides and forest ecosystems. Although they are found mostly in arid environments, some agaves also can flourish in the well-drained areas of wet ecosystems, such as pockets on cliffs or steep graveled slopes.

The genus name Agave originates from the Greek word meaning “noble,” and it is one genus in the Agavaceae family that includes Yucca, Hesperaloe and other genera. Carl Linnaeus, the father of modern taxonomy, assigned the name in 1753. Prior to its modern naming, Aztecs used the indigenous Nahuatl word metl. Another name of Indian origin is mescal or mezcal. Maguey is the most common Spanish word for agave and is traceable to the Antilles, where Spaniards first encountered the plant.

The most common agave leaf form is a rosette arranged in a spiral. The rosette grows on a small, often invisible, single stem, and its pattern allows for maximum moisture collection as water funnels down the leaves to the root zone. Leaves can be thin and long, as with the Agave multifilifera found in northern Mexico, or short and rounded like the Agave titanota found in Oaxaca. Most have sharp teeth on the leaf margins, and leaves can be held in bud for two to three years. In some species, such as Agave colorata, the teeth on the surrounding leaves imprint themselves on the surface of another leaf. The imprint imparts an intriguing pattern known as a “bud imprint.” Leaves may last as long as the life of the plant, which averages in the 15- to 20-year range, depending on the plant’s species, location and growing conditions.

Most agaves are monocarpic, meaning that the rosette dies after flowering, blooming only once in the life of the plant. Some plants might bloom after just three years, while others may live 50 years before flowering. Inflorescences are flower stalks called quiotes in Spanish. They usually grow high above the rosette with spicate that resembles a bottlebrush, or paniculate – cantilevered – blossoms. Some can grow up to 40 feet tall, and flowering may occur for two months or longer. A few agaves flower from the leaf axils and live after blooming.

Agave blossoms are typically yellow, though Davis points out some unusual examples. “There are a few species that have purple flowers; A. pelona, A. potrerana and A. multifilifera come to mind. Agave gypsophila has a distinct bright-orange flower.” He adds, “Agave chrysantha flowers can smell like popcorn, and in my experience and judgment, A. schottii has the most pleasant aroma when flowering.”

Hummingbirds, orioles, bats, bees, moths and other insects feed on agave nectar and pollen, serving as important pollinators. Davis explains that the plants reproduce from seeds, by rhizomes – called pups – and some agaves can reproduce by “making bulbils on the bloom stalk after flowering.” Like the pups, the bulbils are genetically identical clones of the parent plant.

“Some of the most economically important species reproduce in this manner. Agave sisalana and Agave fourcroydes have been used for centuries in fiber production, and Agave tequilana and Agave angustifolia are used for tequila and mescal,” says Davis.

The aesthetic quality of agaves also has attracted people for centuries. Explorers brought specimens back to Europe, where they quickly became a status symbol, appearing in gardens and botanical collections from Spain to England as early as the 16th century.

Davis’ favorite landscaping agaves include  A. havardiana which is native to  western Texas, eastern New Mexico and parts of northern Mexico and A. parryi which is native to  large parts of Arizona, southwestern New Mexico and parts of northern Mexico. Other favorites are A. colorata, A. geminiflora, A. ‘sharkskin’, A. ovatifolia, A. victoriae-reginae and A. utahensis. Low water requirements make agaves desirable for water conservation. “The key is to plant them in well-draining soil, sometimes planting on elevated mounds of sandy soil,” says Davis.

“The combination of cold and wet is the biggest concern. Think about where the warmer, drier microclimates in the landscape might be.” The plants can tolerate cold below freezing, a few down to -20 degrees Fahrenheit. Agaves are particularly attractive as container plants for easy transport when temperatures drop.

Landscape designer Sarah Yant of Austin’s Big Red Sun offers design advice when landscaping with agaves. “Agaves provide commanding form and structure. They should be used judiciously in the landscape; less can be more, depending on the site. They especially stand out when grouped in odd numbers, and planting two or three varieties close together can make for a stunning focal point. Place them where they will ‘pop’ in the landscape.”

“Research sizes of agaves at maturity before purchasing and consider the garden space available,” adds Yant. “Many can get 4 or 5 feet tall and wide, some even bigger. There are also more dwarf varieties available, some growing in beautiful rosette formations (like Agave victoriae-reginae) that do well in smaller gardens or containers. Landscapes can be designed to group agaves with similarly structured plants such as yuccas or sotols or contrasted with native cacti, grasses or flowering plants.”

For safety, Yant recommends people consider children, pets and pedestrian traffic – or plant some of the less spiny varieties (such as Agave bracteosa). “Soft grasses planted in front of or amongst agaves provide movement and contrasting texture and also can serve as a protective barrier. Clip spines off an inch or so from the tip if necessary.”

“Big Red Sun utilizes agaves in combination with native grasses like Muhlenbergia dumosa (bamboo muhly) and Nassella tenuissima (Mexican feather grass),” explains Yant. “Flowering plants with silvery leaves, like Salvia leucantha (Mexican bush sage), complement agaves nicely, as do all of our native Texas wildflowers. Dichondra argentea (silver pony-foot) is a stunning groundcover to use in conjunction with agaves.”

Expanding interest in native landscaping, traditions and preservation bring hope to the protection of agave culture and industry. For more information about landscaping with agaves, try Mary and Gary Irish’s book “Agaves, Yuccas, and Related Plants: A Gardener’s Guide.” Mary Irish points out, “As the world continues to homogenize, native plants help instill a strong regional look into individual gardens.” As more people learn about agave’s fascinating history, ecological contribution and potential modern-day uses, its future can be bright.

Written by Andrea Abel