Those succulents that you thought looked like rocks? They are called Lithops, a genus of succulents native to southern Africa. Older Lithops form clumps of colourful pebbles in their pot, which makes them ideal as an accent piece in your garden. As small and slow-growing plants, they are relatively easy to care for, especially once you get a hang of the routine.
Light & Temperature
Lithops have adapted to tolerate harsh sunlight in their native environment. Thus, the best way to care for them would be to provide 4-5 hours of early sunlight, and partial shade in the afternoon. A south or east window with optimum light is an ideal place for your Lithops. Remember, insufficient sunlight can cause elongated leaves and lost patterns.
Although they are sun-lover, intense heat can damage their foliage and cause sunburn. Be sure to place them in less sunny spots or cover them up if you find their containers absorb too much heat in the summer afternoon.
As Lithops have the capacity to store water for months in their leaves, overwatering can lead to puffy plants, and even to their demise. Also, remember they thrive in desert condition with infrequent moisture and intense sunlight. Therefore, mimicing Lithop growing condition is important to keep them healthy.
Underwatering, however, can result in stunted plants. The trick is to water only when the soil is thoroughly dry (test by inserting a wooden skewer into the soil, and check if it's moist when removed).
When Lithops are growing new leaves, it's best to leave them and not water until the old pair of leaves are completely dried up and withered. This normally happens after their dormant season, which is around spring to early fall. Once the days get shorter and the temperature get cooler in fall, the plants will be active again.