It is a species that particularly prefers light, and loves to be illuminated: when it finds itself having to deal with a reduced amount of light, it grows with an elongated shape that makes it lose its characteristic similarity with the stones. However, it is advisable to pay attention to sun exposure, in the sense that on very hot days the risk of burns is high. To avoid any problems, on hot days it is possible to spray it with a vaporizer. In the event of a change in color due to excessive sun exposure, you need not worry, in the sense that the original shade will reappear on the occasion of the following suit. The Lithops, in essence, should be placed in a sunny and lighted, ventilated place, without stagnation of humidity. In midsummer a light shade is preferable, while in the other seasons there are no problems with direct exposure to the sun.
As far as the soil is concerned, it must be specified that there is no universally recognized substrate as the best for this species: certainly, however, an excellently draining soil is needed, able to make the water flow with a certain speed. A discrete mixture, however, is that composed of silica sand, also coarse, and porous material, such as raw perlite, volcano lava, pumice or fine vermiculite. The sandy soil, in any case, can be replaced by soil for repottings, taking into account, however, that the Lithops suffer from an excess of organic material (which among other things risks encouraging rot). Aesthetically pleasing, not harmful but not very functional, it is instead the river gravel, which is able to drain to a lesser extent than the volcano lava. In practice, the soil must have very little organic matter and drain a lot: to check if it is so, it is enough to pour water over it. If it does not flow quickly, it means that there is a need for additional draining material. The Lithops are characterized by a root system with larger dimensions than the rest of the plant that emerges on the surface. Despite this, it is not essential to use particularly large vessels, and a depth of ten or twelve centimeters goes well. Clay pots do not create problems, but they must be watered more frequently than plastic containers, since terracotta loses moisture very quickly, and any absence of water causes serious damage, connected to the dryness of the roots. The most frequent cause of Lithops death is found in incorrect waterings. In fact, they have a period of rest during which they do not need water: to irrigate them in this period would mean to make them rot. We must begin to irrigate in moderation when the old leaves dry out, and we begin to see below the new growth: more or less the period is between April and June, even if the different weather situations can cause changes. In the early autumn, after flowering, the administration of water must be suspended, until the appearance of the new leaves. The above rules apply to almost all varieties, with the exception of Lithops Optica, which, growing in the winter months, needs to be wetted during growth, but waiting until the soil is completely dry before a new watering. In short, in spring there is need for a watering every two weeks, after the change of leaves, as well as in autumn, before the flowering begins.
Watering and irrigation
It is not necessary to give water to the Lithops, instead, during the moult, in the hottest summer period and in winter. However, it is essential to be able to recognize the signals that the plant sends: in short, experience. Also from the fertilization point of view the Lithops are not very demanding plants: at the most, they need a reduced quantity of fertilizer, not more than once a month in summer, with a high phosphorus content (in order to favor the autumn flowering) and to low nitrogen content. Certainly, excessive fertilization risks causing serious damage, causing the specimen to swell up to split it.
Pests and diseases
The most fearsome pests for these plants are the cochineals, that is the root lice, recognizable by the waxy white secretions they produce. They contrast with relative ease through specific insecticides available on the market. When repotting is carried out, however, it is preferable to mix an insecticide with the mixture. A less chemical remedy is to place two balls of mothballs at the bottom of the vase, so as to keep the scale insects away. Also dangerous are birds, mice and snails, which could nibble the plant: but in this case it is sufficient to prepare some barriers for the vessels. As far as diseases are concerned, the most harmful is, simply, rottenness, which can be caused by too high temperatures, an excessively rich soil of humus, an undrained soil, an excessive humidity in the resting period, too abundant watering that cause stagnation of water.