Crassula mesembryanthemoides aka Cats Tongue

Crassula mesembryanthemoides is a compact succulent subshrub that typically reaches about 40 cm (16 inches) in height at maturity, with a similar spread. It has a slow growth rate and develops a shrubby, branching habit over time. The stems start green and hairy but become woody and reddish-brown with age. The leaves are small, measuring less than 1 cm (0.4 inches) long, and are densely covered with soft white hairs that give the plant its characteristic fuzzy appearance.

Crassula mesembryanthemoides thrives in temperatures between 20°C to 25°C (68°F to 77°F) for optimal growth. It can tolerate warmer temperatures when provided with some afternoon shade. However, it is not cold-hardy and cannot survive frost. The minimum temperature it can handle is around -1°C (30°F), corresponding to USDA zones 10-11. If you live in a colder climate, grow this succulent in a container that can be brought indoors during winter months.

Crassula mesembryanthemoides blooms in fall and winter, producing small, bell-shaped flowers in clusters at the tips of branches. The flowers are typically white to cream in color, sometimes with pale pink tones, and may emit a light fragrance at dusk. Blooming indicates the plant has reached maturity and is healthy. To encourage flowering, provide adequate light (at least 6 hours daily), allow a natural temperature drop in autumn, and reduce watering during the dormant period.

Crassula mesembryanthemoides propagates easily through several methods. The quickest way is separating offsets (pups) that grow around the base of mature plants—gently remove them with some roots attached and plant in well-draining soil. Stem and leaf cuttings also work well: take a clean cutting, allow it to callous for 2-3 days, then place in dry succulent soil. Optionally dip in rooting hormone to speed up the process. Keep cuttings in bright indirect light until roots develop. Spring and early summer are the best times to propagate.

Two subspecies of Crassula mesembryanthemoides are recognized: subsp. mesembryanthemoides and subsp. hispida. The subspecies hispida is sometimes sold separately as 'Crassula Moon Glow' and may have slightly different characteristics. Notable cultivars include 'Tenelli' (featuring a bluish-gray tint with a velvet appearance) and 'Surprise Party' (which produces unusual bright red or violet flowers instead of the typical white/cream blooms). All varieties share the characteristic fuzzy, hairy leaves.

Crassula mesembryanthemoides can grow outdoors year-round in USDA zones 10-11, where temperatures stay above -1°C (30°F). It thrives in partial shade to filtered sun, as intense afternoon sun can scorch the leaves. In colder climates, grow it in a container that can be brought indoors when frost threatens. Outdoors, plant in well-draining soil in a raised bed or rock garden. The plant handles heat well when given afternoon shade and slightly more frequent watering during hot spells.

Repot Crassula mesembryanthemoides when it outgrows its container or the soil becomes compacted, typically every 2-3 years. The best time to repot is in spring when active growth resumes. Choose a pot only slightly larger than the current one with drainage holes. Use fresh, well-draining succulent/cactus soil mixed with perlite or coarse sand. Allow the roots to dry for a day or two before repotting, and wait a week before watering to let any damaged roots heal.

The most common pests affecting Crassula mesembryanthemoides are mealybugs and aphids, which often hide in leaf axils and stem bases. Mealybugs appear as small white cottony clusters. Treat infestations by dabbing with 70% isopropyl alcohol or applying neem oil or insecticidal soap. The main disease concern is root rot from overwatering—prevent it by using well-draining soil and allowing it to dry completely between waterings. Watch for fungal issues like powdery mildew in humid conditions. Remove affected parts promptly.

Yellow leaves on Crassula mesembryanthemoides usually indicate overwatering or root rot. Check the roots—if they're black and mushy, root rot has set in. Remove the plant from wet soil, trim affected roots, let it dry for a day, and repot in fresh dry soil. Other causes include natural leaf aging (older lower leaves may yellow and drop), too little light, or nutrient deficiency. Ensure the plant gets adequate bright indirect light and consider a light feeding with diluted succulent fertilizer during the growing season.

Brown leaves on Crassula mesembryanthemoides typically result from sunburn (crispy brown patches from too much direct sun), underwatering (dried brown tips or shriveled leaves), or cold damage. Move sunburned plants to filtered light. For underwatered plants, give a thorough soaking and resume regular watering. Brown mushy leaves suggest overwatering or rot—remove affected parts and improve drainage. The woody stems naturally turn reddish-brown with age, which is normal and not a cause for concern.

Drooping in Crassula mesembryanthemoides usually signals a watering issue. If the leaves look shriveled and the soil is bone dry, the plant needs water—give it a thorough soaking. If the soil is wet and stems feel soft or mushy, overwatering and root rot are likely the culprits. Remove the plant, inspect roots, trim any rotted portions, let it dry, and repot in fresh well-draining soil. Extreme heat or cold can also cause temporary drooping. Ensure the plant isn't exposed to temperatures below -1°C (30°F).

Crassula mesembryanthemoides is naturally a slow-growing succulent, so limited growth is normal. However, if growth seems unusually stagnant, check the conditions. Insufficient light is the most common cause—ensure at least 6 hours of bright indirect light daily. The plant grows slowly in winter during its semi-dormant period. Other factors include root-bound conditions (repot if needed), depleted soil nutrients (feed lightly in spring), or temperatures outside the ideal 20-25°C (68-77°F) range.

If you're looking for a plant that offers a moderate level of challenge, Cats Tongue is a great choice to test your gardening skills.

Cats Tongue’s native range is South Africa.

Cats Tongue does best in dry soil and should only be watered sparingly.

To keep your Cats Tongue healthy, it's important to use a potting soil that won't retain too much moisture. A soil that drains well and contains perlite or vermiculite for drainage and some organic matter for nutrition is ideal. Adding a few handfuls of perlite to regular cactus soil from the store is an easy way to create this type of soil mix.

Cats Tongue requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Crassula Moon Glow is always in the right place to thrive.

Cats Tongue prefers dry environments, but by misting the plant or providing extra humidity, water will linger on the leaves and create an ideal environment for fungi that could be harmful.

The Cats Tongue is characterized by its slow growth and doesn't need fertilization in addition to its potting soil. By renewing the soil in its pot once a year, it should have enough nutrition. Remember, plants get their energy from sunlight, not from any fertilizers.

There is no verified data on the toxicity of this plant in the records of Ploi. If any person, including yourself, a family member, or a pet, consume plant material with an uncertain toxicity level, it is advisable to seek the advice of a healthcare expert.

During the cold period, it is common for Cats Tongue to go dormant, resulting in a slowdown of growth. To accommodate this, waterings should be spaced out more.