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San Diego Floral Association

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Agaves for Your Garden
Use these sculptural succulents as focal points and in containers

By Debra Lee Baldwin

Garden photojournalist Debra Lee Baldwin is the author of the bestseller, Designing with Succulents (Timber Press, 2007). Portions of this article originally appeared in Gardening How-To magazine.

Camellias

Tuxedo agave
Photo: Debra Lee Baldwin

Reprinted from September/October 2008, Volume 99, Number 5
© SAN DIEGO FLORAL ASSOCIATION. This story and images may not be published in any form or copied onto another website without written permission from San Diego Floral Association.

 

For 15 years I cultivated my half-acre garden in north Escondido without agaves. I was into roses and fluffy perennials and, more recently, succulents that are daisy-shaped or have leaves like ruffled petticoats. Agaves—which resemble artichokes, pincushions or fountains—are the antithesis of such rounded, soft-textured plants. Native to drought-prone regions of the Southwest, Mexico and Central America, agaves tend to be macho and intimidating, with barbed leaf edges and sharp terminal spines.

But because I visit gardens by top designers (as part of my work as a garden photojournalist), I came to realize my own garden was a soft mass, like a photo out of focus. So, several years ago, when a neighbor gave me offsets from his immense yellow-and-green-striped Agave americana ‘Marginata’, I positioned them throughout the garden. It is one of the largest succulents, and when mature, its long, tapered leaves are as wide and long as two-by-fours. These undulate, suggesting motion—a subliminal impact that lends edgy appeal. Having such man-eaters in the garden reminds me of science-fiction thrillers that both delighted and terrified me as a child.

Now when I look down into my garden—which is on a slope, with terraced areas—I view half a dozen Volkswagen-sized plants that resemble, depending on my fancy, immense octopi or lavish striped ribbons. From a design standpoint, these variegated agaves create pleasing repetitions, and serve as focal points for mixed plantings of smaller succulents and fine-textured perennials. At last my garden’s masculine and feminine elements are in balance, and the result pleases my eye and the camera’s.

Agaves reproduce both by plantlets that form along the bloom stalk, and via pups that pop up from lateral roots. Before you know it, the mother plant is surrounded by smaller versions of itself. Each of these may pup, as well. I’ve seen Agave americana grow so thickly, its owner gave up trying to reclaim the land beneath it. But it was partly his fault; he had been too kind. You don’t want to give Agave americana regular water, fertilizer and rich soil. The less TLC the better to keep it
in check.

Agave americana ‘Mediopicta Alba’, which is gray-and-cream striped, and grows to about half the size of the others (to four or five feet tall and as wide), is hardy to 15 degrees Fahrenheit. This elegant, midsized agave is perfect for smaller gardens and also does well in pots. Because of its formal silhouette and coloration—and since its botanical name is unwieldy—I have given it the common name “tuxedo agave.” I combine my americanas with the blue succulent groundcover, Senecio mandraliscae; with annual wildflowers, such as bright orange California poppies; with dainty, butterfly-like gaura; and with gray, feathery-leaved Artemisia ‘Powis Castle’. I also skirt them with lush green aeoniums, and allow bougainvillea and ivy geraniums to caress them with color.

While on tour after my book, Designing with Succulents, came out, I met people beyond our region who have agave envy. I told them there is an agave for every garden, including those in cold climates. And even in the Southwest, gardeners are unaware of how many gorgeous varieties of Agave are available. The genus is remarkably diverse, with species found in habitat from sea level to 9,000 feet. A fairly common agave that, depending on the subspecies, tolerates temperatures to -20 degrees is Agave parryi (three feet tall and four feet wide, over time). It is a large gray artichoke with minimally toothed leaves beautifully tipped in black. I saw it thriving in the Denver Botanic Garden in January, surrounded by snow and shrubs that were dormant sticks. Other agaves that go below zero include Agave havardiana, A. montana and A. utahensis (to -10 degrees), and Agave neomexicana (to -20).

Most agaves tolerate temperatures below freezing for brief periods, but one that is notoriously frost tender—and also very common in San Diego—is soft-leaved Agave attenuata. It resembles a large (to four feet in diameter and as wide) green rose with pointed petals. In my garden, during a midwinter cold snap, it collapsed like wet Kleenex. I trimmed the damaged leaves back, and new growth from the centers of the rosettes also has restored the plants’ beauty. Incidentally, a variegated (yellow-striped) cultivar of Agave attenuata is highly sought-after; even small pups can command hundreds of dollars.

Agaves are famous for being the plant from which tequila is made. Agave tequilana (to eight feet tall and as wide, hardy to 25 degrees) has blue-gray, bayonet-shaped leaves. In Mexico, where it is cultivated commercially, workers whack mature plants back to a pineapple-like core. This is then harvested and cooked, and the juice distilled.

Because agaves are slow-growing when their roots are confined, even potentially immense varieties do fine in pots, sometimes for years. When the soil is gone and the pot crammed with fleshy roots, the agave feeds off its own pantry of nutrients. Keep in mind though, that potentially large agaves may eventually crack and break pots made of low-fired clay.

In retail nurseries over the next few years, we can look forward to seeing beautiful agaves that are much smaller in size compared to immense Agave americana. Here in San Diego, Rancho Soledad Nursery’s (www.ranchosoledad.com) tissue culture division, Rancho Tissue Technologies, has been cloning aesthetically desirable agaves. An example is Agave ‘Blue Flame’, a cross between Agave attenuata and Agave shawii. The hybrid resembles Agave attenuata, but handles much colder temperatures (down to 25 degrees in my garden). Its name comes from blue-green leaves that taper to a point, suggesting flames.

San Diego County also is home to Euro-American Propagators (www.euroamprop.com), a grower and wholesale supplier of ornamental plants under the Proven Winners label, and which has a new line of succulents that includes a half-dozen agaves. Among these is Agave geminiflora, which has dark green leaves margined in wispy white filaments. Near Santa Barbara is San Marcos Growers (www.sanmarcosgrowers.com) that offers, among many others, mid-sized Agave ‘Cornelius’, with wavy leaves boldly striped yellow-and-green. Such suppliers are making beautiful agaves available in an array of varieties, in quantity, throughout the Southwest and nationwide.

Ten agaves that do well in San Diego gardens

These stay manageably small (three to five feet in diameter and as tall):

  • Agave americana ‘Mediopicta Alba’ (tuxedo agave): Has an upright, fountain-shaped silhouette and cream-striped, blue-gray leaves.
  • Agave angustifolia ‘Variegata’: Knife-like leaves are striped cream and green.
  • Agave attenuata: Resembles a large rose with tapered, soft green leaves. Frost tender.
  • Agave ‘Blue Glow’: The color of the leaves—a blue-green faintly streaked with gray— suggests a watercolor painting. Thin red leaf margins glow beautifully when backlit.
  • Agave bovicornuta: Green leaves are patterned with white scalloped indentations left by other leaves before they unfurled. Crimson teeth line leaf margins.
  • Agave bracteosa: Slender, curling green leaves lack teeth or spines.
  • Agave geminiflora: A pincushion agave that forms whorls of dense, compact rosettes.
  • Agave potatorum: A blue-gray agave with orange prickles along the leaf edges and terminal spines that twist.
  • Agave ‘Sharkskin’: Thick, gunmetal-gray and sandpaper-textured leaves give the plant sculptural appeal.
  • Agave victoria-reginae: A cold-hardy (to 10 degrees) agave named after Queen Victoria. Has dark green, wedge-shaped leaves crisply outlined in white.

Caring for agaves

  • Agaves are tough, easy-care succulents that tolerate less than ideal conditions. To optimize the plants’ health and vitality:
  • Let soil go dry between waterings. Typical of most succulents, agaves latch onto soil moisture, which they retain efficiently. But agaves don’t know what to do with too much water, and after plumping up, may become sodden and rot.
  • Grow agaves atop mounds or on a slope, so water drains away from the roots.
  • Grow potted agaves in fast-draining “cactus mix” potting soil, or make your own by combining two parts regular potting soil with one part pumice or perlite.
  • Amend your garden soil with decomposed granite. Agaves will grow in pure decomposed granite, so you can’t overdo it.
  • Give solid-colored agaves full sun, variegated varieties partial afternoon shade.
  • Know an agave’s cold hardiness, and cover it with a bed sheet to protect it if temperatures will briefly drop below its tolerance.
  • Fertilize half strength in spring when the plants emerge from dormancy.
  • Don’t let dirt or leaf debris, which trap moisture and invite insects, settle into an agave’s leaf axils.
  • Know the size at maturity of any agave you plant. Some species become huge, and because of barbed tips, can be hazardous, especially alongside walkways.
  • If you must trim an overlarge agave, preserve its symmetry by cutting the leaves flush with the stem rather than truncating them half way.
  • Realize that agaves die after blooming, and plan accordingly; don’t position one where it may be a challenge to remove. Most agaves take upwards of five years to bloom, and some, like “century plants” may take 15 years or more.
  • Watch for pups (offsets) and detach them if you don’t want a colony.

September/October 2008, Volume 99, Number 5
© SAN DIEGO FLORAL ASSOCIATION. This story may not be published in any form or copied onto another website without written permission from San Diego Floral Association.


Mission: To promote the knowledge and appreciation of horticulture and floriculture in the San Diego region.







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