In the Garden Articles

Succulents

by Joan S. Bolton

Think succulents only belong in cactus gardens?

Not anymore. The low-maintenance, thick-stemmed plants are one of the hottest trends in water-conserving gardens. Their colorful foliage and sculptural forms stand out year-round, providing an attractive counterpoint to flowering shrubs and perennials that may wax and wane with the seasons.

By definition, succulents are plants that store water in their fleshy leaves and stems to survive periods of drought. In practice, they belong to a group of plants that has traditionally been relegated to tiny 2-inch and 4-inch pots in the collector's corner of garden centers.

But that's beginning to change. Heightened interest in low-water native and Mediterranean plants has expanded to succulents as well. Fortunately for us, that means they're becoming more readily available in a greater variety and in larger sizes.

Getting Started

The Central Coast offers an ideal climate for growing succulents. Many are native to hot, dry climates with gritty soil. The sandy soil that at least a few of us curse turns out to be a blessing. Succulents are susceptible to rot if their roots get waterlogged, and that sandy soil drains fast. If your garden is flat or the soil is heavy, mound the area at least 6 inches to a foot tall before planting to improve the drainage.

Good starter plants include aeoniums, agaves, aloes, crassulas, echeverias, euphorbias, kalanchoes, sedums, senecios and ice plant. The names may be unfamiliar at first, but they'll soon become second nature.

Agaves and aloes range from small to very large, sculptural, stand-alone plants. The biggest drawback of agaves is that once they bloom -- typically in seven to 15 years, depending on the species -- they die. Some, including the fox tail agave (Agave attenuata), also melt in freezing temperatures like those we experienced earlier this year.

The thick leaves of aeoniums and echeverias (AKA hen and chicks) often form a pattern that looks like a plump daisy. The plants come in countless shades of green, gray, blue, white, beige, pink, red and burgundy, and may be striped, splashed or splotched with complementary or contrasting colors.

Crassulas include the long-popular jade plants. Euphorbias have become a hybridizer's delight, with all sorts of new, knee-high, variegated plants coming on the market. Kalanchoes include the popular florist plants that will grow just fine outdoors here.

Senecio mandraliscae, sometimes called kleinia or dead-man's claw, forms a blue-green ground cover of curved, upward-reaching leaves. It's terrific as an edging along a walkway. The many sedums and ice plants also look good in masses, forming close-knit, flat ground covers.

You can mix any of these succulents with other water-conserving plants or ornamental grasses. Just be sure that your soil drains well and that everyone's watering needs match. One of the nifty things about succulents is that they -- unlike some drought-tolerant plants -- don't mind the overspray from sprinklers. So they're good transition plants between a lawn and dryer areas of your garden.

Yet they'll also survive on watering as little as only a few times a month during summer. Unless you see their thick leaves literally shrivel, they're getting all the moisture they need.

Collecting Ideas

Wander your neighborhood, peruse nurseries and skim gardening magazines, all of which are featuring more succulents than ever.

If you're planning a wholesale renovation of your garden, an excellent source of ideas is "Designing With Succulents," a new book by Debra Lee Baldwin (Timber Press, 2007). The pages are filled with photos, many from California gardens. The text is geared to the overall aesthetic qualities of the plants and is organized according to their size and use, rather than nuances that only botanists might appreciate.

It's interesting to note than when Baldwin began growing succulents in her San Diego garden more than a decade ago, utility was foremost on her mind.

"I wasn't thinking about design. I was just thinking about plants that would grow in gaps, that were supremely low maintenance, and that I could start by taking a cutting and sticking it in the ground," she said.

"Another thing, when I take a cutting and stick it in the ground, I don't water it for a week," she added. "Watering cuttings is counterproductive because of the threat of rot. You want those tiny roots to form before watering."

Over time, however, Baldwin said she shifted from collecting a little bit of this and a little bit of that to applying design techniques to her garden.

"I'm not a collector. I'm the opposite of a collector. I choose succulents that can be used in repetition and contrasts," she explained. "I strive for something that's cohesive, has rhythm to it. Maybe that's the difference. Rather than just growing succulents because they're easy, I try to combine them in ways that are aesthetically pleasing."

As an example, Baldwin cites Agave americana 'Marginata', which is a century plant with yellow stripes along the edges of its undulating leaves.

"I just love them. I have them strategically placed throughout my garden. The stripes are gorgeous. It's like putting a giant ribbon in your garden."

On its own, she added, she uses marginata as a focal point. "It (a single plant) suggests a fountain. Then I have aeoniums to suggest splashing water around the base."

In her book, Baldwin displays photos of succulents in combination with non-succulents as well. In one striking image, a yellow-striped fox tail agave is surrounded by yellow and orange nasturtiums. In another photo, the thick, pointed leaves of a gray-green fox tail agave contrast with the wispy plumes of Mexican feather grass and stout flower stalks of French lavender.

"I actually prefer gardens that incorporate drought-tolerant companion plants," she said. "I enjoy the texture and the feel of being in a garden that isn't just a showcase of someone's collection."

Other compelling compositions include a blue-tinged agave rising above blue-blooming rosemary; upright, gray-leaved century plants paired with an equally upright, brightly variegated New Zealand flax in front of an intense San Diego Red bougainvillea ground cover; and rolling swaths of orange, yellow and iridescent purple ice plant.

Succulents also grow well in pots. In one particularly sweet photo, Baldwin zeroes in on a cobalt blue pot containing a variety of flat, pink and blue-tinged echeverias and lime-green aeoniums. They're mulched with blue and green glass pebbles. The effect looks remarkably like water lilies floating in a pond.

For more information about Baldwin or her book, visit www.debraleebaldwin.com or www.timberpress.com.

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Size and Other Considerations

Beware of the ultimate size of your succulents. That sweet little tree aloe (Aloe arborescens) will eventually form a mound 6 to 12 feet tall and wide. A diminutive gray century plant (Agave americana) will grow 10 feet tall and wide, with nasty spines at the tip of each and every leaf.

Debra Lee Baldwin, author of "Designing with Succulents," actually snips off an inch or two of any tips that are close to walkways. "I trim that back, just like a fingernail," she said.

As for what to do with the surrounding space while you're waiting for the big guys to fill in: underplant with a succulent ground cover such as kleinia (Senecio mandraliscae), red apple (Aptenia cordifolia) or ice plant (Delosperma, Drosanthemum, Malephora or Lampranthus). Or plant clumps of blue fescue (Festuca glauca).

Mulch around your new plants to conserve water. Crushed rock, pea gravel and decomposed granite are popular choices. If you use bark, keep it an inch or two away. The wood holds moisture. If left in contact with the succulent leaves for too long, it can lead to rot.

Seeds of Wisdom

Some succulents are more tolerant of heavy soil than others. But all appreciate fast drainage. If there's any doubt, plant your succulents on mounds and keep them out of the valleys between.