Both Crassula ovata (Jade Plant) and Crassula arborescens (Silver Jade Plant) are sun-loving succulents that thrive in bright light conditions. However, their ideal light intensity differs slightly. Crassula ovata is highly adaptable and can tolerate a few hours of direct sunlight but prefers bright, indirect light for most of the day, which promotes its classic deep green, sometimes red-edged, foliage. In contrast, Crassula arborescens has a higher demand for intense, direct sunlight. Its beautiful silvery-gray leaves, often with reddish margins, develop their best color and a protective powdery coating (farina) only when exposed to several hours of strong direct sun. Insufficient light will cause both plants to become etiolated, but C. arborescens will show its dissatisfaction more quickly by losing its compact form and silvery hue.
As succulents, both species have evolved to store water in their fleshy leaves and stems, making them highly drought-tolerant. Their watering needs are almost identical and are dictated by the "soak and dry" method. The soil must be allowed to dry out completely between waterings to prevent root rot. The primary difference stems from their leaf physiology. The thinner leaves of Crassula ovata may wrinkle slightly when thirsty, providing a clear visual cue. The thicker, rounder leaves of Crassula arborescens hold more water and may not show signs of thirst as quickly. Both require an exceptionally well-draining soil mix, typically a cactus or succulent potting mix amended with extra perlite or pumice to ensure no water is retained around the roots.
Originating from South Africa, both plants prefer a warm, dry environment reminiscent of their native habitat. They are not frost-tolerant and must be protected from temperatures dipping below 50°F (10°C). Ideal growing temperatures range from 65°F to 75°F (18°C to 24°C). While they can handle typical household humidity, Crassula arborescens is particularly sensitive to high humidity and poor air circulation. Its dense, rounded leaves can trap moisture, making it more susceptible to fungal diseases and leaf rot in stagnant, humid air compared to the slightly more forgiving Crassula ovata. Excellent airflow around the leaves of C. arborescens is crucial for its health.
This is an area of significant difference between the two species. Crassula ovata is a comparatively vigorous grower, developing a thick, woody trunk and branches relatively quickly. It is often pruned and trained as a bonsai subject due to its responsive growth. Crassula arborescens, on the other hand, is a much slower-growing plant in cultivation. It takes its time to form its characteristic tree-like structure and thick, silver-dollar leaves. This slower metabolism means it requires less frequent repotting and feeding. While both benefit from a diluted succulent fertilizer during the growing season, over-fertilizing C. arborescens can be more detrimental due to its slower growth rate.
