How to care for and cultivate living stone plants: tips for the propagation and maintenance of lithops.

How to Care for LithopsSummary: This article discusses the care and cultivation techniques for Lithops, providing detailed information for enthusiasts.Cultivation and Care Techniques for Lithops(I) The process of Lithops sowingLithops is a variety favored by many succulent lovers and is highly sought after. However, due to the complexity and meticulous nature of Lithops sowing and seedling management, it has always been a challenge for enthusiasts and a difficult process to master.1. Selection of seedling potsThe best pots for sowing Lithops are purple sand pots, as they have the most ideal permeability. However, due to the variety of sowing species, I have chosen plastic square pots with dimensions of 7cm x 7cm x 8cm, each of which can sow at least 100 seeds.2. Sowing substrateThe substrate for sowing Lithops is a key link, involving future seedling management and care issues. Improper use can lead to low germination rates and premature seedling death. Learning from my past lessons, the substrate I used for sowing this year is divided into three parts: bottom stone, middle layer soil, and surface soil.Bottom stone: Large particles of orchid stone are used as the bottom stone to enhance permeability and aeration, 1-2 cm thick.Middle layer soil: This part of the soil accounts for more than 70% of the pot soil, so it is the foundation for future plant growth and the source of nutrition supply. I use Akadama soil, orchid stone, granular cultivation soil, and a small amount of rice husk charcoal. The Akadama soil, orchid stone, and granular cultivation soil should be sifted to remove the dust and debris, ensuring that the particle diameter of the three substrates is between 1mm and 5mm. These three substrates can be mixed in a ratio of 1:1:1 to ensure loose and breathable soil, and then a small amount of rice husk charcoal is added to increase nutrition.Akadama soil, orchid stone, and granular cultivation soil pictures;Surface soil: The surface soil is the seedbed for seed development and growth, so it needs to be carefully selected. I use sieved 1mm diameter green stone particles, Akadama soil, and鹿沼土 mixed as the surface soil, with a thickness of about 1cm.3. Disinfection of the substrate(1) Why disinfect the substrate? The disinfection of the substrate is to prevent the growth of fungi and pests, ensuring the safe and healthy growth of seedlings. The main diseases during the seedling stage are damping-off, caused by fungi. Since fungi are saprophytic fungi, it is necessary to disinfect them.(2) Preparation of potassium permanganate solution. Previously, I used a microwave to disinfect the substrate, with high heat for 10-15 minutes. However, due to the unpleasant smell of using a microwave for disinfection and the limited amount of substrate that can be disinfected each time, this year I used potassium permanganate solution to disinfect the substrate. Potassium permanganate is a strong oxidant that can quickly disinfect the substrate. Prepare potassium permanganate water solution using hot water to dissolve, with a concentration of 0.3%-0.5%, which means that when the water solution is clear and dark purple, it basically meets the requirements.(3) Specific steps and methods for disinfection. After the above substrates are prepared and potted, immerse the flower pot in the potassium permanganate water solution. The time is not particularly required, usually 10 minutes. After the pot is taken out, it is dried. If it is exposed to strong sunlight, it is better.4. Sowing seedsSince Lithops seeds are very small, sowing is an extremely meticulous and patient job. The main process is as follows:Ci) Sowing time. The best temperature for sowing Lithops is 15-25℃, so it is necessary to choose the right time to sow according to the local climate conditions.(2) Disinfection. After the surface of the pot soil is smoothed and compacted, spray with broad-spectrum fungicides such as carbendazim, thiophanate-methyl, mancozeb, and chlorothalonil.(3) Sowing. Lithops seeds are small, and it is almost impossible to complete sowing with spot sowing, so it is usually carried out with broadcast sowing. Use a piece of hard white paper folded to form a trough. Place the seeds carefully on the white paper and gently tap the back of the white paper so that the seeds can be evenly and smoothly flowed into the area you want to sow. It should be noted that the angle of inclination of the white paper and the strength of tapping are the key to seed broadcasting, which requires continuous exploration and practice to master.(4) Surface soil covering. Regarding whether to cover soil on the surface after sowing, there are various methods. I did not cover the surface soil after sowing.(5) Disinfection. Spray the pot surface with broad-spectrum fungicides again, which can make the seeds better combined with the surface soil and also disinfect the seeds.(6) Marking. Insert marking plates on the seedling pots according to the sequence of the seeds to avoid confusion and facilitate future management.5. Placement of seedling potsAfter sowing, it is usually necessary to cover the pot mouth with glass or plastic wrap, cling film, etc. to maintain a certain humidity in the local environment, facilitating the germination of seeds as soon as possible. Due to the difficulty in controlling the time for ventilation and reducing humidity, this year I chose a large plastic box to create a relatively larger environment. The advantage of this is that the space environment is larger, which can effectively prevent the death of seedlings due to water droplets on the film. Place the seedling pots in order in the large plastic box, cover the lid, and place it in a place with scattered light, using the scattered light of the sun as the light source.(II) Several issues in the care of Lithops1. The growth rate of Lithops is not slowRegarding the growth of Lithops, many flower books and magazines believe that it grows slowly and is complex to manage. Therefore, although the unique shape of Lithops attracts many enthusiasts, due to this misunderstanding, there are not many people who inquire and cultivate it in China. In fact, many flower books and magazines are copied from each other, and it is rare to have firsthand information from personal practice, just copying each other.Lithops are usually sown for propagation in March and April, and the seedlings will emerge in 6-15 days after sowing. Due to the small size of the seeds, the seedlings are also weak after germination. The small seedlings just emerged indeed grow slowly, so care should be meticulous and careful, especially to prevent the invasion of harmful fungi.After a month, the plant begins to grow, but the nutrition of the seeds themselves is basically exhausted, and the function of self-made nutrients has not yet fully formed, so it is necessary to timely supplement the nutrients needed for growth and provide lighting (3000-10000 lux). At the same time, it is necessary to prevent excessive lighting from causing excessive anthocyanin deposition in young plants, inhibiting growth.The key to the good or bad growth of Lithops seedlings in the later stage lies in the care between 50-80 days. The method of supplementing nutrition is to use a dilute compound fertilizer with the same nitrogen, phosphorus, and potassium ratio for spraying. This can make the leaves absorb and also provide a small amount of fertilizer solution for the roots to absorb, with a concentration controlled below 1.5%. During this period, the temperature should be controlled between 15-30℃. After 3 months, the small plants can reach the size of mung beans. However, the weather is getting hot at this time, so attention should be paid to ventilation and cooling, slightly drying the substrate, and preventing the high temperature and humidity from causing seedling rot and high temperature leading to dormancy.In autumn, the weather gradually cools down, and seedlings can be divided and planted with a spacing of 2 cm. After a period of slow growth for two weeks, the seedlings have grown a little larger, and strong seedling care should be carried out, spraying with dilute liquid fertilizer every 10 days. By late October, increase the amount and duration of lighting, and the plant body can reach 12mm. After December, when the weather gradually cools down, full lighting and insulation and humidification measures should be taken to prevent the substrate from being too wet or too dry. Continue to care for the second year, and the cotyledons will split, and the new leaves (true leaves) will begin to grow.By mid-April, the plant body can reach 20mm. From sowing to counting, 13-14 months later, the seedlings can be sold as commercial seedlings. If they continue to be cultivated, the cultivation soil should be replaced every half a year, and by the age of 24 months, the plant body can reach more than 35mm and become a standard plant, but it cannot bloom and rarely increases in number.In addition, it has been observed that the growth rate of individual varieties with green or purple-black skin is significantly higher than that of red-purple varieties.2. Issues regarding the dormancy of LithopsIt has been found that the decisive factor causing Lithops to enter dormancy is temperature, followed by lighting. To break the dormancy of Lithops, it is necessary to start from these aspects. Practice has shown that as long as the temperature is maintained at 15-28℃ from late spring to early autumn, one-year-old seedlings should be less fertilized with nitrogen fertilizer, more frequently fertilized with dilute phosphorus and potassium fertilizer, and the cultivation substrate should not be too dry or too wet. Shading 70%, reducing the lighting time to 5-7 hours per day, and forming a day and night temperature difference of 8-10℃, Lithops can grow throughout the year. It just grows faster or slower due to seasonal changes. In temperate regions, the above method can be used to break summer dormancy. In the north, most houses have heating facilities in winter. As long as Lithops are placed in an environment above 10-15℃ with normal sunlight and additional 20-40 watt light sources to extend the lighting time, winter dormancy can be broken. Relatively speaking, winter dormancy is easier to break than summer dormancy.3. Methods to accelerate the growth rate of LithopsBreaking the winter and summer dormancy of Lithops will undoubtedly promote its growth. In the condition of temperature control, in the north, after the winter, placing it on a sunny windowsill or enclosed balcony with heating can make Lithops bloom for the first time before the Spring Festival. At this time, fertilization should be appropriate, and the amount of watering should be slightly increased. Do not shade, because the ultraviolet rays have been discounted when sunlight passes through the glass. Loosen the cultivation substrate every half month without injuring the roots, and persist until early April, when the new leaves will grow to the size of the old leaves. At this time, the old leaves and new leaves are superimposed in a cross shape, and the old leaves are not wrinkled, which does not affect the appreciation during the Spring Festival. Of course, methods such as heating or cooling can also be used to make the old leaves split. In the north, stop heating the house in mid-March, and the outside temperature rises to about 4-15℃. The room temperature is 10-21℃, at this time, less water should be poured to increase the concentration of the new leaf sap. If the temperature is slightly lowered to maintain about 7-18℃ and form a significant temperature difference with the day and night changes, the effect is better. By early May, when the outside temperature rises to 16-25℃, the plant will again show the phenomenon of the new leaves splitting the old leaves, and there is a possibility of an increase in the number of heads. By mid-June, the plant already has 3 pairs of leaves, and although the lowest layer of leaves is wrinkled, they are still superimposed in a cross shape. Analyzing the above situation, the fundamental factor is still temperature. From the coolness in October to the heating and temperature rise in November, it promotes the first splitting in January, and the subsequent temperature conditions make the new leaves grow and mature. After stopping heating in March, it enters a state of cooling, and after heating in late April, the plant grows vigorously again, and new leaves grow, promoting the second splitting. In fact, under human conditions, the plant experiences two winters and two summers in about 270 days from October of the previous year to May of the following year, completing a two-year growth and development process in nature. This method accelerates the increase in the size of individual Lithops or the increase in the number of heads, but whether it can promote flowering and seed production needs further observation and research.4. Substrate issue of potted LithopsLike other succulent plants, Lithops are still mainly cultivated with soil as the substrate. Overall, two points should be kept in mind: loose and breathable, rich in organic matter. I am accustomed to using commercially available Clivia soil mixed with 1/3 perlite or vermiculite as the cultivation substrate, and adding a small amount of superphosphate. In a pot with a depth of 15-20cm, lay a layer of broken pot shards 3-4cm thick, add a layer of fine brick particles 2cm thick, put some decomposed sheep manure or oilseed cake, and then add the mixed cultivation soil to 1cm from the edge of the pot. Press it slightly, insert holes with bamboo sticks, carefully put the Lithops seedling roots into it, and press and bury it to the root and stem junction from all sides. It doesn't matter if a few plants shake slightly. When preparing the cultivation soil and transplanting, the water content must be controlled, making it the best when it can be formed into a ball by hand and scattered when the hand is loosened. After transplanting, do not water, place it in a place with weak light and warmth (15-20℃), and sprinkle a little water around the plant after a week. Normal management can be carried out after half a month. With this method of transplanting, whether it is changing pots and soil for old plants or planting seedlings mailed from other places, the survival rate is 100%, with no damage. [Jishan Hua Yao]5. Fertilization issue in the cultivation of LithopsSeveral years of practice have shown that the base fertilizer for Lithops is best with decomposed sheep manure. Because after decomposition, it is cool and rich in potassium, with a pH of about 7.2, and mixed with oilseed cake, it supplements trace elements and nitrogen fertilizer, with comprehensive nutrients, not dry or too strong. Adding superphosphate also supplements phosphorus and calcium, making it play a role in the slightly alkaline substrate. Therefore, the plant roots grow well, the leaf shape is full and shiny, the number of split heads increases, and it is easy to bloom and produce seeds. In general, the root fertilization uses multi-element compound fertilizer, and organic fertilizer leachate can also be used. Mature plants should use less fertilizer with high nitrogen content or high inorganic salt concentration. When applying root fertilization, prevent fertilizer solution from staining the plant body. Foliar spraying uses commonly used ornamental foliage nutrient solution. When the new leaves open and the old leaves split, directly apply urea, 6-8 grains for large plants and 3-4 grains for small plants to promote the rapid growth of new leaves. However, prevent water accumulation at the new split to avoid plant body rot. Fertilization and watering should be carried out simultaneously, trying to apply thin and frequent fertilization, and never be impatient, so as not to cause fertilizer damage.6. Cultivation and management of introduced plantsIntroducing Lithops usually only introduces seedlings, and seeds can only be introduced occasionally, and the variety and quality of introduced seeds are not guaranteed. The market often only sells small seedlings, and there are few mature plants for sale. Therefore, most introducers can only buy small seedlings by mail. Lithops seedlings are small, and usually undergo a drying treatment before mailing. They are wrapped in soft and breathable paper and mailed to the introducer after 5-8 days or longer. Although the plant body will not suffer much loss, the roots are very dry, and some plants' roots break easily, leaving only the fleshy leaves or the root and stem junction connected, which is a pity to discard, but cultivation is also worrying about survival problems.In fact, Lithops in the native land is very drought-resistant, and sometimes the roots have no water for more than half a year. The more lignified roots will shrink, relying only on the reversed water of the leaves to preserve the roots. But as long as it is not absolutely dehydrated, when the environmental conditions improve, the old roots will absorb water, swell, and regenerate new roots. If the old roots break and fall off, and the plant body does not rot, new roots will regenerate from the remaining part of the main root. Based on these situations, the Lithops seedlings received by mail should not be planted in a hurry. First, dip the roots in water, place them on moist soil in a mild environment for 8-12 hours, and then plant them with the aforementioned transplanting method, without the need for root-promoting agents. New roots will grow after 5-7 days, pay attention to the amount of watering, and normal management can be carried out after half a month, and fertilization can be promoted for growth after 20 days. Some plants are completely rootless, but they can be retained as long as the plant body does not rot. Use loose and breathable substrate, in an environment of 15-25℃ to use cutting method to root. When cutting, there is no need to shade or moisturize, and tender white roots will grow in 10-15 days. After the roots are 0.2-0.7cm long, transplant, with a high survival rate. This method can also be used for the propagation of Lithops by division.The above shares the full content of how to care for Lithops, Lithops planting and care techniques, hoping to be helpful to plant enthusiasts!