With plants, as with people, there are savers and spenders. Where water is the currency, succulents are the thriftiest of their kind, their fleshy leaves hoarding water for times of drought. This built-in resiliency makes them a perfect choice for problem places in the yard: patio containers set in the blazing sun, windy spots that make roses wither, rocky slopes where grass will not grow. For years, gardeners in the arid West have been using succulents in water-thrifty xeriscapes. Now more nurseries are carrying these intriguing plants, some growing well even in damp or cold climates.
John Spain, a Connecticut-based gardening expert who pioneered growing succulents outdoors in the frozen north, discovered their advantages years ago when he often traveled for business. "The only plants that survived without any care in my makeshift greenhouse were the succulents and cacti," he says. "I would leave for a month, and they would be fine." That sent him searching for more cold-hardy succulents. Finally, he found enough to fill a 20-foot (6 m) long berm with a carpetlike tapestry of leaves in green, chartreuse, rose, purple, and even nearly black. Today he also tucks succulents among alpine plants in his 2,000-square-foot rock garden.
A Size and Shape for Every Situation
At least 60 plant families have some succulent species. The adaptations that these plants have made to hold on to moisture make them especially interesting garden specimens. Ground-hugging rosettes pack water into thick, pointed leaves that hybridizers have edged with ribbons of color or rose-petal-like frills. Some species have a swollen stem known as a caudex that serves as a water storage tank. Others resemble cacti, complete with ridged stems and spiky thorns.
Among the most well-known succulents are Sedums, including perennial favorite Sedum spectabile 'Autumn Joy', which grows 18 to 24 inches (45 to 60 cm) tall and bears dramatic rosy-red flower heads in late summer. Another Sedum, Two-Row Stonecrop (Sedum spurium), is a low-maintenance groundcover with fine foliage and white, pink, or purple flowers in summer. Low-growing Sedum rupestre 'Angelina' has yellow flowers.
Another groundcover, Ice Plant (Delosperma spp.), has tiny, fingerlike fleshy leaves and blooms in full sun with masses of daisylike flowers all summer. Delosperma nubigenum is a noninvasive type that bears yellow blooms.
Hens and Chicks, the common name for the similar-looking but unrelated Echeveria 'Imbricata' and the more cold-hardy Sempervivum tectorum, is a longtime favorite for containers, rock gardens, and growing in the crevices of stone walls. Sempervivum's ground-hugging rosettes can be green, red, chartreuse, or purple to silvery blue. Echeverias come in rose, green, gray, and mauve, often with a contrasting edge color or a stripe. Both multiply without much effort, sending out shoots with their progeny attached; these may root on their own if they contact the soil. Otherwise, they can easily be detached and rooted.
Desert-loving Yuccas, Agaves, and Aloes add a sculptural element to any garden with their swordlike and strappy leaves with sharp tips. Though these large-scale specimen plants have long been associated with the dry Southwest, hardy varieties withstand below-freezing temperatures.
That indoor classic, the treelike Jade Plant (Crassula ovata), is another favorite for outdoor containers, though it is not hardy in cold climates. In the same family, Crassula 'Baby's Necklace' looks like a string of beads or buttons.
The lesser-known, multistemmed Aeoniums bear striking rosettes, sometimes variegated, in shades of green, red, and blackish purple, at their branches' ends. Equally good as container and garden specimens, these generally grow 18 inches to 3 feet (45 to 90 cm) tall and 2 to 4 feet (60 to 120 cm) wide. They do not tolerate freezing temperatures, however, so they need to winter indoors in cold climates.
Planting and Care
Although succulents generally require minimal care, most have one absolute need: good drainage. Many have shallow roots that spread out so they can take advantage of even brief rainstorms. But the roots succumb to disease if they stay damp.
The right soil depends on rainfall where you live. In desert areas, some succulents grow even in clay. However, in wetter climates, mix sand and airy lava rock into the planting area. Dig holes only as big as the nursery containers or even a little less deep so that the plant crowns do not settle below the surface, mulch with pea gravel to keep surface moisture to a minimum. For containers, mix two-thirds gravel or lava rock and one-third loam if you live where there is a lot of rain. In a dry climate, reverse the proportions.
Most importantly, do not overwater. Though container plantings need more water than those settled into the ground, probe the soil to ensure it is thoroughly dried out before watering. And always empty any standing water from saucers. In garden areas, feel the soil 3 to 4 inches (7.5 to 10 cm) below the surface to make sure it is thoroughly dry before giving plants a good dousing.
Occasional rainfall may mean you will only need to water succulent plantings now and then, even during the year's sultriest weeks. That is when you may appreciate the savings bonus these plants offer, not just the lower water bill but the extra hours freed up from coddling your summer garden.
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus