Sipping a margarita laced with the distilled sap of Agave tequilana while cocooned in a hammock woven from the fibers of A. sisalana might be as close as most of us have been to an agave. Many gardeners are reluctant to consider them—they think of agaves as too big, too ferocious, or too odd. But these admirable plants have been shunned for too long. With their hard edges, impeccable form, and extraordinary vigor, agaves add interest and contrast to any garden. Happily, the number and variety of agaves available to gardeners has exploded in recent years, fueled by the increasing interest in native and desert-adapted plants, as well as by the increasing number of enthusiastic growers.
Agaves grow naturally in a vast array of habitats, from seashores to high desert mountains; along dry limestone canyons and flowing stream beds; among semi-arid grasslands and sere desert plains. Their geographic range extends from Utah and Nevada south through the American Southwest and throughout Mexico to Central America. This bounty means that there's an agave suitable to almost any style of garden in almost any climate.
In the West, agaves are content with native, rocky soils, but they grow equally well in fertile garden soils as long as drainage is excellent. For areas with denser, wetter soils, the addition of sand, gravel, or other rocky amendments is critical to their success.
Although strongly identified with dry gardens (most species thrive on 12 to 15 inches of rain a year), many agaves flourish with much more water—again, provided drainage is perfect. In the desert areas of the Southwest, agaves need to be regularly watered through the hottest parts of the summer but generally need little supplemental irrigation in the cooler months. In cooler climates, like the Pacific Northwest, agaves need occasional irrigation during dry summers, but must be protected from too much rain during the long, wet winters. In most of the rest of the country, agaves with adequate cold tolerance can be grown successfully as long as they are protected from winter's most severe onslaughts. (See “Growing Agaves in Cold Climates.")
5 Top Agave
If you look through old gardening texts, five agaves show up again and again: A. filifera, A. lechuguilla, A. lophantha, A. schidigera, and A. xylonacantha. These old favorites are being rediscovered by gardeners all over the country. All are modest size plants, two to four feet tall and wide, with striking leaf colors; they grow equally well in alkaline, rocky soils or richer garden soils. Because of their size and attractive leaves, all members of this group make splendid complements to a mixed planting of perennials or wildflowers, or to the frothy sprays of ornamental grasses.
Agave filifera has flat, smooth-margined, deep green leaves marked with white and trimmed with the trailing white filaments that inspired its name. Agave schidigera is similar, but the leaves are deeper green. It is also entirely solitary, whereas A. filifera makes at least a few offsets, or “pups.” Agave lechuguilla is only 12 to 18 inches tall, with thin, upward-curving, yellow-green leaves marked on the back by pale striations. Agave lophantha is highly variable, but most forms have flat, dark green leaves usually marked by a wide, pale stripe down the middle with widely spaced gray to white teeth along a white margin. Agave xylonacantha grows to four feet tall and wide, with dusky gray-green leaves lined with a white undulating border and flat, highly irregular, white to gray teeth. All are hardy to at least 10‘F, with A, lechuguilla hardy to 0˚F.
Large agaves are not for every garden, but where they can be accommodated, they have an undeniably dramatic presence. The blue-gray giant, A. americana, does well in a wide range of conditions, but there are also attractive alternatives to this ubiquitous species. Agave franzosinii is nearly as large—up to six feet tall and wide—but has graceful, recurved, powdery blue to white leaves. Agave salmiana is equally large, but its firm, succulent leaves are glossy green, with a deep curve at the tip.
Small and Medium Agave
One of the most commonly grown agaves is the native A. parryi. Rarely over two feet tall and wide, this species is renowned for its blue-gray leaves rimmed in deep maroon and for its elegant symmetry. It grows equally well in the hot deserts and high-mountain areas, and because it is hardy to 0°F, it is one of the most successful agaves for gardeners in cold climates. The variety truncata is a gorgeous plant distinguished by almost round leaves and a tight rosette that looks like an artichoke bud. It is hardy to about 10° F.
Agave havardiana and A. neomexicana, from western Texas and eastern Mexico, respectively, are newer to the ornamental stage but make striking ornamentals for higher-elevation gardens in the West or other cold areas. Agave havardiana is characterized by thick, rigid gray-green leaves in a spreading rosette. Agave neomexicana is more variable, with a tendency to be paler than A. havardiana. Some forms in cultivation are almost white with a deep maroon edge.
The growing popularity of smaller agaves has brought many other fine ornamental species into prominence. Among them is A. utahensis, from the canyon country of northern Arizona and adjacent Nevada and Utah. Growing two to three feet tall, this agave has thin, gray-green leaves with pale teeth spaced regularly along the edges. Although hardy to at least -20° F, this species dies quickly if kept too wet. The solitary variety kaibabensis has bright green leaves and whitish, regularly spaced teeth; the gray-green subspecies nevadensis has prominent teeth and an elongated terminal spine; and the bizarre variety eborispina is remarkable for its whitish, papery terminal spine that looks like the elongated fingernail of a Chinese mandarin.
One of the most striking of all agaves and the darling of any collection is the Queen Victoria agave, A. victoriae-reginae. The numerous triangular leaves are thick and rigid, their dark green, smooth surface scored with white. The paired dark terminal spines are short but sharp. Standing only 12 inches tall, this Chihuahuan species has many hybrid forms (usually with A. scabra), which sometimes go by the obsolete name A. ferdinandi-regis. Most hybrid forms are larger and dusky green to gray green, but very handsome nonetheless. This species is superb in a container; its extreme symmetry makes it a stunning sight when viewed from above. Hardy to 0° F, this is a useful plant throughout most of the country.
The list goes on and on. The solitary A. ocahui, with numerous flat, dark green, white-margined leaves; A. bovicornuta, with shiny green leaves accented by rust-color teeth; or the bristly A. geminiflora, with hundreds of grass-thin, nearly round, light green leaves—all are plants to excite the gardener's imagination. Plant a few, and next spring you can not only lie on agave fibers and sip agave beverages, but also gaze out over a garden punctuated by these remarkable plants.