While both belonging to the Crassula genus, Crassula ovata (Jade Plant) and Crassula arborescens (Silver Dollar Jade) exhibit distinct physical characteristics that inform their care. C. ovata typically has smaller, oval-shaped, jade-green leaves that may develop red margins when sun-stressed. In contrast, C. arborescens is distinguished by its larger, almost circular, silvery-blue leaves adorned with distinctive red spots along the margins. This difference in leaf morphology is a key indicator of their light tolerance. The silvery, glaucous coating on the leaves of C. arborescens is a natural sunscreen, reflecting intense sunlight and making it slightly more tolerant of very strong, direct light compared to C. ovata. However, both species require ample light to maintain compact growth and prevent etiolation.
The fundamental "soak and dry" method applies to both succulents, but their tolerance for moisture varies due to their leaf structure. Crassula arborescens, with its thicker, fleshier leaves, is exceptionally drought-tolerant. It stores significant water reserves and is more susceptible to overwatering if the soil remains moist for extended periods. It is crucial to allow the soil to dry out completely, and then wait a few more days, before watering again. Crassula ovata, while still a succulent, can handle slightly more frequent watering. Its leaves are slightly less plump, indicating a relatively faster consumption of water. During the active growing season (spring and summer), C. ovata may require watering as soon as the top inch or two of soil is dry, whereas C. arborescens prefers a longer dry period between drinks. For both, watering should be drastically reduced in winter during their dormant period.
This is a critical area of differentiation. Crassula ovata is marginally more cold-tolerant than Crassula arborescens. C. ovata can typically withstand brief dips in temperature to around 30°F (-1°C), though it should not be subjected to freezing conditions for sustained periods. C. arborescens is more tender and can suffer damage at temperatures below 40°F (4°C). Its cells are more susceptible to freezing, which causes the water inside to expand and rupture cell walls, leading to mushy, blackened leaves and stems. Therefore, gardeners in climates with frost must be more vigilant with C. arborescens, bringing it indoors earlier in the autumn. Both species thrive in the warm, dry conditions typical of their native South African habitats and prefer a significant day-night temperature fluctuation.
The specific epithet "arborescens" means "tree-like," and this species lives up to its name by developing a thicker, more substantial trunk and a branching structure that more closely resembles a miniature tree at a younger age compared to C. ovata. Crassula arborescens generally has a slower growth rate. Crassula ovata, often called the "Money Tree," is a faster grower under ideal conditions and can become a large, sprawling shrub. This difference in growth habit influences pruning and potting. C. ovata may require more frequent pruning to maintain a desired shape and prevent leggy growth, especially if light levels are insufficient. The slower growth of C. arborescens means it can often remain in the same pot for longer periods and requires less frequent structural pruning.
Both plants demand exceptionally well-draining soil to prevent root rot. A commercial cactus and succulent mix is suitable, but amending it with additional inorganic materials like perlite, pumice, or coarse sand (up to a 50:50 ratio) is highly recommended. Due to its higher sensitivity to overwatering, Crassula arborescens benefits from an even grittier, faster-draining mix than C. ovata. The choice of pot is also important; unglazed terracotta pots are ideal for both as they are porous, allowing the soil to dry out more evenly and quickly, which is particularly advantageous for the more delicate root system of C. arborescens.
