Living stones (Lithops spp.), also known as pebble plants, are unusual little succulent plants that have evolved to look like the pebbles and rocks of their native habitats in Africa. These plants hug the ground and grow extremely slowly. They’re best planted in the spring or fall, as living stones enter a dormant state and aren’t actively growing during the hot summer months or the winter months.
The plants within this genus generally consist of a pair of thick leaves with little (if any) stem above the soil. Beneath the soil is the stem and fairly long roots. A new set of leaves appears in the spring, and the old leaves dry up and fall off. All species within this genus have daisy-like flowers, which typically emerge from the fissure between the leaves in the fall or winter.
|Common Name||Living stones, pebble plants|
|Botanical Name||Lithops spp.|
|Plant Type||Succulent, perennial|
|Mature Size||0.5–2 in. tall, 0.5–2 in. wide|
|Soil Type||Sandy, well-drained|
|Soil pH||Acidic, neutral, alkaline|
|Bloom Time||Fall, early winter|
|Flower Color||White, yellow, orange|
|Hardiness Zones||10–11 (USDA)|
Living Stones Care
Living stones are quite interesting plants to grow, thanks to their unique appearance. They are very low-maintenance plants. However, they have specific environmental needs that must be met for plant owners to keep them healthy.
These plants need as much light as possible. If you’re growing living stones indoors and don’t have a bright window, you might need to invest in an artificial grow light for them. Moreover, proper watering is usually the most crucial part of caring for this species. Living stones are highly tolerant of drought, and too much water can easily kill them—especially if it promotes root rot or fungal growth. Fortunately, living stones aren’t prone to many diseases, so they should thrive if you take a largely hands-off approach to their care. In fact, for about half of the year, you likely won't have to do anything aside from monitoring them to ensure they're healthy.
Living stones prefer full sun year-round, meaning at least six hours of sunlight on most days. When growing these succulents indoors, place them by your brightest window (south-facing exposure is best). Insufficient light can cause elongated leaves and poor leaf coloring.
These plants like sandy soil with plenty of drainage. A potting mix formulated for cacti is ideal for living stones, and the container should have several holes on the bottom for drainage.
Living stones must be watered on a seasonal schedule that mimics the rainfall they would get in their natural habitat. Don’t water in summer or over the winter when the plant is dormant. Then drench the soil, allowing it to dry our completely before watering again--about 1-2 weeks. Once the new leaves begin forming in the spring, water whenever the soil dries out—just enough to make it slightly moist. Pause watering again in the summer during the plant's second dormant period. Resume watering in early fall, just before the plant is ready to flower. If the leaves start to completely shrivel up while the plant is dormant, you can give it a very small amount of water to plump them up again.
Temperature and Humidity
Living stones tolerate heat well, and they can survive temperatures as low as 50 degrees Fahrenheit. They do fine in typical room temperatures between 65 and 80 degrees. Humidity usually isn’t an issue, as long as the soil doesn’t remain moist for long periods and there is good airflow around the plants.
These plants live naturally in poor soil and aren't heavy feeders, but a low-nitrogen, high-potassium fertilizer helps encourage flowering.
Types of Living Stones
There are more three dozen species of living stones and more than 140 varieties, including:
- Lithops julii: This species has pinkish-gray leaves with brown markings.
- Lithops gracilidelineata: Pale, gray-white leaves with brown markings look like cracks in the leaves’ surface of this variety.
- Lithops lesliei: This succulent has barely any stem above ground, and it features markings of green, pink, orange, gray, and brown.
- Lithops marmorata: This plant features smooth, gray-green leaves with a marbled pattern.
While it's not necessary to prune the leaves of your living stones, it is helpful to remove dead leaves as needed. The few plump, succulent leaves above the surface of the soil will begin to shrivel when new leaves start growing after the plant's flowering season.
Propagating Living Stones
Living stones naturally multiply by growing new plants on their own in the same container. Once several plants are growing together, it's possible to propagate this species manually by division to prevent them from overtaking the pot. This process should be completed in the spring when the plants are actively growing. Here's how:
- Prepare new containers for each living stone that you plan to separate from the cluster. The containers should be deep enough to accommodate the plants' taproots, which can grow to about 6 inches long.
- Carefully remove your living stones from the pot and gently separate the plants, taking care not to rip or damage any of their roots.
- Using a clean pair of gardening shears, cut between each living stone. Make sure that each plant has an intact taproot.
- Fill the new containers with a well-draining cactus soil mix, then place the individual living stones into their new pots.
- Water the soil lightly and care for the plants the same way as described above.
How to Grow Living Stones From Seed
Your living stones will produce flowers in fall, which fade into seed pods that can be harvested to grow new plants after the flower dies back. Here's how:
- Locate the seed pod on your living stone. Using a clean pair of gardening shears, trim the pod from the plant.
- Submerge the pod in water or use a dropper to add a few drops of water to its exterior. The pod will begin to open. (In its natural habitat, rain causes the seed pod to open.)
- Once the pod is open, use a toothpick or a pair of tweezers to gently scrape the seeds out from inside.
- Prepare a new pot with a well-draining cactus soil mix. Moisten the soil with water.
- Sprinkle the seeds from your living stones on the soil's surface and cover them with a thin coat of sand.
- Water the container just often enough to keep the sand moist, but not soggy. Once the seeds sprout, begin watering them less often and care for the plants the same way as described above.
Potting and Repotting Living Stones
Even though these plants only rise about an inch above the soil, provide them with a pot that’s about 6 inches deep. This is because they have long taproots that stretch far down into the soil. The pot should also have ample drainage holes. An unglazed clay pot is ideal, as it allows excess water to evaporate through its walls.
You likely won’t have to repot your living stones for many years since they grow so slowly. If you have several plants in a pot that are becoming cramped, carefully dig up each plant you want to repot, keeping its roots intact. Place it in a new pot that’s slightly deeper than the length of its roots, filling around it with fresh cactus potting mix.
Living stones can survive somewhat cold temperatures, so in warmer climates (USDA Hardiness Zones 10-11), these plants can grow outside year-round and even be planted directly in the ground. In colder regions of the country, it's best to bring your plants indoors for the winter, so they should be grown in portable containers. Once temperatures are consistently above 50 degrees in the spring, your living stones can be taken back outside.
Living stones are susceptible to a few different types of pests. Spider mites are most common, but mealybugs, scale, thrips, and aphids can all present problems as well. Living stones planted in the ground outdoors or living in pots on your patio may also become targets for small mammals and pests like snails or slugs.
To treat spider mite infestations, mix rubbing alcohol and water in equal parts and mist it on your plants. Other pests on living stones can be treated with insecticidal soap.
How to Get Living Stones to Bloom
Most living stones bloom in the fall with flowers that resemble daisies, but some varieties can bloom in late summer or even spring. The flowers may be white, yellow, or orange, and they emerge between the leaves of the plant. While fertilizer is not typically recommended for these plants, some gardeners choose to use a potassium-based fertilizer diluted in water to encourage blooming. These flowers eventually die off and leave seed pods behind if the flower was pollinated, so if you plan to harvest your plant's seeds, don't deadhead its flowers. Living stones are self-sterile, so they need pollination to produce seeds. After flowering, living stones go dormant—meaning it's time to stop watering the plant until spring.
Common Problems With Living Stones
Living stones are typically easy plants to tend, but they can also develop a few growing problems. This is most commonly related to improper light or water, which can be adjusted to keep your plants healthy.
Your living stones may begin to lose their color when they're not receiving enough sunlight. Too little light can also cause the leaves to grow in an elongated shape as the plant reaches for the sun. In either of these cases, move your living stones to a spot with full sun to help resolve the issue.
Shriveled or Wrinkled Leaves
Living stones don't commonly have problems with too little water, although it's possible for them to develop shriveled or wrinkled leaves during the spring and fall when they're too dry while actively growing. Add just enough water to make your plant's soil slightly moist. Misting the soil—not the leaves—can also help ensure the plant isn't soaked.
If your plant's leaves feel overly soft or mushy to the touch, it's likely receiving too much water. Overwatering can lead to root rot, which also makes living stones more appealing to pests. Always avoid watering during your plant's dormant seasons, and ensure the soil is moist (but never soggy) to the touch during spring and fall.
How do you keep living stones alive?
Living stones are exceptionally easy plants to keep alive, requiring minimal watering and care steps for much of the year. Place your plant in an area with full sun, and during spring and fall, lightly water the soil when it dries out (avoid watering in summer and winter).
How long do living stones live?
As very long-lived plants, you can expect your living stones to survive for up to 50 years with the proper care and growing conditions.
Do living stones multiply?
Living stones multiply on their own by dropping seeds from the pods that are left behind when their flowers wilt. Gardeners can divide the new plants and transplant them to other containers if the original pot becomes crowded.
Living Stones. Wisconsin Horticulture Division of Extension.