General Mesemb Care Info

Mesembs, also known as “Ice Plants” or ‘Mimicry Plants’ are a group of succulents that are highly desirable by collectors to grow but can be difficult to care for.  Mesembs is shorthand for mesembryanthemums, a genus of succulent plants commonly known as ice plants. Mesembryanthemum is a large genus that includes over 1,300 species of plants native to Africa, the Middle East, and southern Europe.

Mesembs are popular succulents grown for their colorful flowers and adaptations to arid conditions. They have thick, fleshy leaves and stems that allow them to store water and thrive in dry, sunny climates and soils. In this guide, we will explore the basics of growing them, including the seasonal growing cycle, soil requirements, light and air needs, and watering techniques.

What are the basics of growing mesembs?

Mesembs are a highly sought after group of plants to grow, but the ease of killing them has discouraged many potential succulent collectors from enjoying the full spectrum of this group of plants. The name mesemb is short for the Sub Family Mesembryanthemaceae. They get the name ‘Mimicry Plants’ because in the wild they mimic rocks and other natural features of their habitat.

Success in growing mesembs is providing the right balance of light, circulating air, water and well-draining soil. These succulents require a little more attention (that doesn’t mean watering and messing with them) than others. One must be aware of the seasonal growing cycle, and sensitive to how much water and when as well as what it should look like when it’s healthy during its yearly cycle.

How does the seasonal growing cycle affect mesembs?

Knowledge of the plants seasonal growing cycle is super important in keeping mesembs alive and thriving. Basically there are two possible growing categories; summer or winter growers. The summer growers actually start growing (waking up) in mid spring, kind of slow down in the mid summer heat, and then have a flourish of growth in early fall. Winter growers wake up in late summer to mid fall, grow quickly for awhile, slow down in mid winter, then have a flourish of growth in the spring.

The main issue most hobbyist succulent collectors is knowing the plants dormant season, summer growing mesembs don’t like to be watered during their winter dormancy, and winter growing plants don’t like to be watered in the hot summer or being out in the full sun being cooked all summer long. But during the spring and fall almost any mesemb can be watered- if it is showing signs of needing water. Again, mesembs can be some of the trickiest succulents to keep alive.

What kind of soil do mesembs need?

Mesembs require a well-draining soil, which means it dries out quickly. Basically the soil should contain a higher proportion of pumice, perlite or coarse sand. I use a lot of pumice in my soil mix for mesembs to make sure that they don’t sit in wet soil longer than they need to.

How much light and air do mesembs require?

All mesembs require a lot of light and moving air (meaning not humid or stagnant air). High heat is not necessary, but a decent area with lots of sunny exposure is required, some shading is recommended during the summer and heat waves. I keep mine under a covered porch that receives a lot of afternoon sun. Moving air is of utmost importance to keep these succulents happy and healthy.

What are some unique adaptations of mesembs?

Here are some unique adaptations of mesembs:

• Thick, fleshy leaves and stems. Mesembs have succulent leaves and stems that store water. This is an adaptation to arid environments where water is scarce. The succulent tissues allow mesembs to survive periods of drought by using the stored water in their leaves and stems.

• Development of papillae. Some mesembs develop papillae, which are small projections on the leaves and stems. The papillae help reflect sunlight and reduce water loss through transpiration. They are an adaptation that helps mesembs conserve moisture in hot, dry climates.

• Stomata that open at night. The stomata of mesembs open at night instead of during the day. This is an adaptation to reduce water loss, since transpiration is lower at night when temperatures are cooler. The nighttime opening of stomata allows mesembs to take in carbon dioxide for photosynthesis while minimizing water loss.

• Burrowing roots. Some mesembs have roots that burrow deep into the soil to absorb moisture. These burrowing roots are an adaptation to arid conditions, allowing the plants to reach groundwater even if it is deep underground. The burrowing roots help mesembs survive drought and high temperatures by providing an additional source of water beyond what is available near the soil surface.

• Seed dormancy and longevity. Mesembs produce seeds that can remain dormant in the soil for long periods until the right conditions occur for germination. The seeds are well-adapted to persist through times of drought and high temperatures. Once conditions are favorable, the seeds germinate to produce new plants. This seed dormancy and longevity is an adaptation that helps ensure the survival of mesemb populations even if environmental conditions are not suitable for growth.

What are some examples of mesembs that develop papillae?

Some mesembs that develop papillae include:

• Pleiospilos nelii, also known as split rock. This mesemb has papillae on its spherical leaves that give the appearance of the surface of a split rock. The papillae help reflect sunlight and reduce transpiration in the hot, dry climate where this mesemb is native.

• Titanopsis calcarea. This mesemb has papillae on its triangular leaves. The leaf papillae are an adaptation to the dry, sunny conditions in the plant’s native habitat in South Africa. The papillae help Titanopsis calcarea conserve moisture by reducing transpiration.

• Dinteranthus vanzylii. This mesemb develops papillae on its leaves and stems. The papillae are most prominent on new growth and help reflect sunlight and reduce water loss. As the papillae age, they become less obvious. The papillae are an adaptation allowing Dinteranthus vanzylii to survive in its arid environment.

• Gibbaeum gummosum. This mesemb has papillae on the rounded leaves growing from its upper stems. The papillae help reflect sunlight and limit transpiration, adapting Gibbaeum gummosum to the dry conditions in its native habitat in South Africa. The papillae, along with the succulent leaves and stems, enable this mesemb to thrive with minimal rainfall.

Those are some examples of mesembs that develop papillae as an adaptation to arid conditions. The papillae help these succulents conserve moisture by reducing transpiration in hot, dry environments.