Lithops

Living Stones is a genus of succulents that grow up to 6 inches tall and are a part of the ice plant family (Aizoaceae). They are native to southern Africa where they are accustomed to full sun, rocky soil, and droughts. In 1811, William John Burchell discovered these small plants that looked like brown stones in southern Africa while on a botanical expedition. The genus name, Lithops, originates from the Greek words, lithos meaning "stone" and -opis meaning "like."

The average rainfall is generally less than 20 inches per year in their native habitat and occurs mostly in the spring and fall. Some species are in areas where they are dependent on mist or fog for moisture.

Living stones grow best in 4 to 5 hours of sunlight in the morning and partial shade in the afternoon. They can tolerate temperatures up to 90 to 100 degrees Fahrenheit, but they will also thrive in temperatures between 65 to 80 degrees. They do not tolerate temperatures below 40 degrees and must be protected from freezing. Watering this plant is based on its growth cycle. Water the plant from late spring to early summer. Stop watering during the summer months while it is dormant.  At the end of summer, water once every 2 weeks while they are actively growing and blooming. During the winter and early spring do not water them at all. The old leaves die at this time, and the new leaves will form in the spring. A cactus mix or fast-draining, gritty potting mix is needed and will allow for good drainage. The plant can be propagated by seeds or division.

Living stones blend in with their surroundings and are found in sandy hills, stony ridges, and in decomposed shale, limestone, or granite. There are about 38 species, and they vary in shape, markings, color, and texture. The Living Stones have a long lifespan, up to 40 or 50 years. This plant grows very slowly and usually is only 1 inch above the soil. Each plant has two succulent leaves with a fissure on the top of the plant that divides the two leaves. Lithops develop a new pair of leaves every year and only have one pair at a time. The leaves are thick and can store enough water to allow the plant to survive for months without rain. The plant is stemless and 0.5 to 1 inch tall and 1 to 3 inches wide. They remain very small and grow close to the ground. Their leaf tips have window cells that allow sunlight into the inner portion of the leaf. The plant blooms in the fall and early winter and has a daisy-like flower that emerges from the fissure between the two leaves. The flowers may be yellow, pale orange, or white, sometimes scented, and are 0.5 to 1.5 inches in diameter. The flowers are open on sunny days and close later in the day. The fruit is a 4- to 8-chambered capsule with tiny seeds inside. When the capsule opens the seeds may be dispersed.

This popular houseplant that masquerades as a stone will be the subject of conversation in your home or office. It is small, unique, and will fit well on a windowsill or desk.

Insects, Diseases, and Other Plant Problems:  Monitor for spider mites, thrips, scale, mealybugs, aphids, snails, slugs, and root-knot nematodes. Outdoors, mice or small animals may try to eat this plant due to its water content. Overwatering may cause yellowing and mushy leaves, brown spots, splitting of the leaves, and root rot. Insufficient light will cause the plant to stretch which is known as etiolation.