Eccentric little rock stars
THE lure of lithops begins with a double-take, the realization that these pebbles are actually plants, alive and growing. See these succulents in a specialty nursery -- or run across them at Home Depot or Lowe’s -- and you may feel like a gem collector who can’t resist a few more cabochons. Perhaps the mottled pink ones? Or maybe the lovely dove gray flecked with green?
Lithops can be almost as tough as stones too. They’ve adapted to the most inhospitable growing conditions imaginable: sandy deserts that get no rain most of the year. Ascetics of the plant world, lithops spurn rich soil and regular water. Conventional wisdom about how to keep a plant happy doesn’t apply.
“I must get 10 e-mails a day asking how much and when to water them,” says Steven Hammer, a world-renowned authority on lithops who lives in Vista, in San Diego County.
Tan and lean, with silver hair and beard, Hammer looks the part of an explorer of the South African veldt in his khaki shorts and hat. He has gone to Africa nearly every year -- 25 times so far -- to see lithops and other genera of ice plant “in habitat,” and after writing five scholarly books on the subject, he now earns a living (“spurns is more like it,” he says with a grin) selling the plants to nurseries, collectors and large-scale growers.
Hammer says The Times launched his lifelong passion.
“In the early ‘60s, when I was 11, the paper ran an article about succulents,” he says. “My dad and I visited a specialty nursery, which back then was in Paramount. I saw lithops and fell in love. It’s as simple as that.”
Hammer says he’s fascinated by the plants’ subtle colors, their infinitely varied and agate-like forms, the way they change so slowly -- “a fingernail rate,” he says. The size of the plant also is part of its appeal. A collector can present the entire genus in a square yard, Hammer says.
Thousands of plants in his greenhouses grow in 4- or 6-inch-square plastic pots. Many hunker in a sandy potting medium with just their tops showing, resembling single- or double-headed buttons with a fissure down the middle. They are surprisingly firm to the touch and pocked with translucent “windows” that enable photosynthesis.
Lithops that are rounded and peach-colored remind some people of baby bottoms. (German collectors call lithops Hottentotenpopo, and “popo” is slang for “butt.”) The Khoisan people (formerly known as Hottentots) of southern Africa noted that lithops resemble the C-shaped tracks of horse hooves and call the plants the Afrikaans word for the same. In English, the common nickname is “living stones,” though these stones can turn to mush without proper care.
Gardeners can get hung up on soil formulas and watering schedules, and that’s unfortunate, because lithops are easy to maintain once you understand their needs.
“The secret is to observe them, which, by the way, is not a chore but a pleasure,” Hammer says.
He suggests growing lithops in coarse, fast-draining soil. In their native habitat, the plants thrive in mineral-based soils poor in organic matter, and they receive only a few inches of rain a year. A good soil mix is more white than brown: Think one part commercial potting soil with twigs removed, and two parts perlite or pumice. If you use perlite, which floats, add a top dressing of gravel. The addition of decomposed granite will help toughen the plants.
Grow lithops in pots, not garden beds. Indoors, Hammer says, “they grow very well in a bright eastern window, close to the glass.” A southern exposure will work as well; west isn’t quite as good; and northern will invite failure.
The type of pot doesn’t matter much, but if you’re concerned about overwatering, clay will keep them drier -- and will last longer than plastic.
The plants need four or five hours of full sun daily. Given too little light, lithops will elongate. Morning sun is ideal. Protect them from scorching afternoon sun in summer. If new plants have been in a greenhouse, introduce them to sun gradually so they don’t burn. One trick is to drape them with a paper napkin for several days.
Leave lithops alone from late fall through spring. Around November, the plant body will open to produce a new pair of leaves. As these grow, they feed off the old leaves, which gradually shrivel and become paper thin.
In winter, protect lithops from frost. Begin watering in spring, once absorption of old leaves is complete. Through summer, observe the plants and water only if wrinkles appear for several days. (Late afternoon “stress wrinkles” don’t count.) Let water drench the roots and flow out of the bottom of the pot. Cut back watering if the plants bloat; lithops may split or rot when engorged.
Most of all, enjoy them. In summer, watch for shimmering flowers to appear. Be sure to sniff them. They’re sweet-scented.
Debra Lee Baldwin is a garden writer and photographer based in Southern California. She is the author of “Designing With Succulents,” released this year by Timber Press.
(BEGIN TEXT OF INFOBOX)
Where to find them
Some major garden centers carry lithops, but specialty sources have wider selections:
California Cactus Center: 216 S. Rosemead Blvd., Pasadena; (626) 795-2788; www.cactuscenter.com.
The Plant Man: 2615 Congress St., San Diego; (619) 297-0077.
Daniel’s Specialty Nursery: Mail-order operation based in Lakeside, Calif.; www.danielscactus.hypermart.net.
Living Stones Nursery: Mail-order operation in Tucson; (520) 628-8773; www.lithops.net.
DEBRA LEE BALDWIN