EDDIE SEAGLE: Century plants have their day in the sun

“That beautiful season the summer! Filled was the air with a dreamy and magical light; And the landscape lay as if new created in all the freshness of childhood.”

— Henry Wadsworth Longfellow

The days of July are passing very quickly and August will soon be here. As you travel about the streets and highways throughout the area, there is a plant that will catch your attention — the century plant in bloom. Agave americana (its scientific name) is a tall agave plant which was once thought to bloom every 100 years (thus its name). Once grown for medicinal purposes, it is now mostly cultivated for ornamental applications and curb appeal. The century plant (aka maguey or American aloe) is a species of flowering plant in the Agavaceae family and Agave genus which originated in Mexico but has been cultivated around the globe as an ornamental plant.

There are many species of agave plants, and some are even used as houseplants. Agave plants are characterized by their long leaves that terminate in a point, sometimes including a thorn. These plants are commonly found in dry desert-scapes, xeriscape landscapes, freelancing in the wild or as ornamental additions to landscape gardens. Before blooming, the century plant looks similar to an ordinary ground palm with a rosette of long, pointed leaves spreading out from a central core. The root of this plant was used by various Native American tribes as a food source. The sap of the century plant is poisonous and causes severe skin irritations.

As you learn more about this magnificent plant, your amazement will continue to grow. Century plants bloom only once in their lifetime and then die. They will remain in the vegetative stage for several years, all the while preparing for the “grand slam” ending as the flower stalk develops. It is almost like a plant on steroids to see this magnificent occurrence. At the onset of flowering, the blooming spike develops very quickly (in a couple of months) and becomes so very large that it depletes all the resources of the plant. This stalk can grow upwards to over 20 feet high and over one-foot in diameter at its base in the middle of the rosette foliage. As it dies, a tall wooden seed stalk is left behind. This plant is called the “century” plant because of this so called “once a century” blooming process. But, in reality, the century plant actually lives about 25 years on the average.

These magnificent plants can be found throughout south Georgia with their flower stalk reaching towards the heavens, unveiling beautiful bouquets of flowers for our visual enjoyment. The century plant is the classic of all the agaves and grows slowly to about six feet tall and ten feet wide with wide, grey-green leaves with curved teeth along the margins of the blades and stiff terminal spines or thorns. After a few years (15 to 25), a tall, central stalk of spectacular flowers develop which signals the end of the century plant’s life cycle. The flower stalk (yellow to orange to red spikes) starts out like a giant stalk of asparagus and grows vigorously for months, forming a glorious bouquet of yellow flowers about three to four inches long. Also, multiple offshoots develop around the base of the plant. Variegated cultivars of the century plant are available in alternate leaf colors and patterns. This large agave should be planted in open, low-traffic areas to minimize potential people injuries from the sharp and dangerous leaf tips.

It prefers exposure in full sun, well-drained soils, and is adaptable to a wide range of conditions. The century plant needs watering about once a month during the summer and no supplemental irrigation in the winter. Proper design and placement into the landscape is critical. If it crowds a pathway or walkway, prune only the terminal spine for improved safety. Do not prune the living leaves since such pruning invites infection. The century plant is very susceptible to the agave snout weevil which promotes wilting and death of the leaves. The plant will not recover from such injury, and the removal of the dead plant can be a difficult process because of its large size and texture.

Bats, hummingbirds and moths serve as the vectors which pollinate the agave from whence tequila, food and other products are derived. People have been harvesting and utilizing agaves for over 9,000 years, and this huge plant comprised a huge part of primitive man’s diet. Agave americana (from Mexico) is the most common of the agaves. These plants are closely related to lilies and offer three major edible parts (flowers, stalks or basal rosettes, and the sap). The leaves are the least edible part of the plant. Also, indigenous people used the century plant for medicines, fiber, needles and food.

During the summer, the agaves can produce several pounds of flowers which can be boiled or roasted. Before they blossom in the summer, the stalks can be roasted and taste similar to molasses. As you remove the stalk, leave a depression in the bottom and it will fill with sap (which can be used to make tequila). The root is very caustic and needs to be handled with care. However, it will become sweet after a couple of days of cooking. The flower nectar can be used to make sauces and sugar. But keep in mind that edible parts differ significantly with each species of agave.

The leaves contain saponins which seem to reduce blood cholesterol levels, reduce the risk of cancer and stimulate our immune system. These leaves, which are rich in sap in the winter and spring, can be roasted for chewing or boiled into a juice as a soup. Since there are over 200 agave species, be sure that you select an edible species, which are differentiated by spine arrangement, length and shape (old and tough are the best). Also be reminded that raw agave juice can cause dermatitis through the calcium oxalate raphides. Never cut an agave with a chain saw and always wear eye and body protection when working around them.

Several species have been used for food in some form including americana, atrovirens, cantala, chrysantha, complicata, crassipina, deserti, palmeri, paryi, salmiana, scabra, shawii, sisalana, tequilana and utahensis. However, avoid Agave lechuguilla, which is known to be toxic and can be found in Texas, New Mexico and northern Mexico. Sometimes it is planted as an ornamental and can sicken sheep, goats and cattle.

The agave has been called nature’s hardware store because of its use in the production of fiber, razor strops, pens, nails, needles and didgeridoos (aboriginal wind instruments). Furthermore, the raw leaves can be beaten to get a foamy material which is similar to soap.

The American century plant is a prominent component in the landscape and looks good in a group planting or as the focal point. It also performs well in large containers and is very tolerant of heat and xeric conditions. However, temperatures in the teens could be damaging to this plant, especially if it is in a standalone environment.

May the results of your immediate efforts be long-lasting so that you can enjoy the fruits of your labor for seasons to come. Think sustainability! Keep your hanging baskets and potted plants refreshed with water and food. Remember to feed and water the songbirds, and give your pets the care they need (do not leave them unattended in a hot car or tied to a tree all day long). Also, be on lookout for children playing along the streets and roadways throughout our communities this summer. Let’s keep everyone safe!

“Then I heard the voice of the Lord saying, “Whom shall I send? And who will go for us?” And I said, “Here am I. Send me!”” Isaiah 6:8

Eddie Seagle is a sustainability associate, Golf Environment Organization (Scotland); agronomist and horticulturalist, CSI: Seagle (Consulting Services International); professor emeritus and honorary alumnus, Abraham Baldwin Agricultural College, and associate editor of The Golf Course, International Journal of Golf Science. Direct inquiries to [email protected].