DESCRIPTION: This large group consists of succulent plants that are natives of South Africa and Madagascar. The succulents in this group vary greatly in shape and size. Some varieties only grow an inch high at maturity, while others become 15-foot trees. C. ovata (Jade Plant; Chinese Rubber Tree; Money Plant) is an evergreen succulent that forms a large bush or small tree. Its shiny green, fleshy leaves are round or lance shaped and sometimes edged with red. In the spring, its old leaves fall; at this time, this variety will benefit from pruning in order to maintain a nice shape. From late fall to mid-winter, thick clusters of white flowers are borne. This species can grow up to 15 feet high and 5 feet wide. C. arborescens (Silver Dollar Plant) is a handsome variety with fleshy, waxy, round leaves. In a sunny location, the bluish-green leaves will be edged in red. This bush needs to be pruned on a regular basis to prevent the heavy leaves from weighing down the brown stems. This variety can grow up to 10 feet high and 4 feet wide. In late fall, pink flowers are borne. C. falcata (Airplane Plant; Propeller Plant; Scarlet Paintbrush) is an interesting plant that grows up to 9 inches high with a spread of 10 feet. This plant has silvery-gray, propeller-shaped leaves. The long stems of this variety eventually lay down to form a spreading clump. New shoots will then grow from the plant's base and the stem tips; use these shoots as cuttings and get rid of the old plants. Clusters of tiny, fragrant, red flowers grow atop the long stems. C. streyi is a low growing plant that reaches a height of 12 inches with a spread of 6 feet. In the shade, the leaves are glossy dark green on the upper surfaces and wine red on the undersides. In the sun, the colors are less vibrant. In the fall, clusters of white flowers are produced. C. muscosa forms a shrublet with stems 2 inches wide and 10 inches high. Sometimes tiny flowers are produced in the summer. This variety makes a great houseplant and can withstand intense heat and sun, but no frost. C. 'Morgan's Pink' is a hybrid produced by crossing C. falcata and C. mesembryanthemopsis. This variety develops into a compact plant up to 2 inches wide. It has chubby, silvery-green leaves and produces a short-stemmed cluster of small, pink flowers. This hybrid also makes a great houseplant.
POTTING: Crassulas can be grown outdoors in regions where the temperature doesn't drop below 41º and 50º F, depending upon the variety; otherwise, some varieties can be grown in the greenhouse or home. The best compost to use for these plants is two parts loam and one part of equal amounts of sand and broken brick. If grown in a container, March is the best time for repotting, or as soon as new growth begins. After potting, no water is needed until the soil becomes pretty dry. Water is given freely to well-rooted plants in the summer, but in the winter, just enough water should be given to prevent the shoots from shriveling. These plants will benefit from some pruning to maintain neat shapes. C. ovata should be pruned in the spring, when it sheds its old leaves; C. shmidtii and C. tetragona should be pruned after they’ve flowered. Large clumps of C. 'Morgan's Beauty' should be lifted and divided in the winter to prevent the clumps from rotting. These plants can be grown in sun or light shade.
PROPAGATION: Cuttings taken in March can be used to reproduce this plant. Shoots that are about 3 inches long should be cut cleanly across the bottom joint and their bottom leaves should be removed. They should be set out for a few hours so that a protective skin will form over the cut. They can then be inserted into sand and not given any water until it becomes dry. After they root, they should be planted in 3-inch pots and eventually into 5-inch pots. These plants can also be increased by seeds and leaf cuttings.
VARIETIES: C. falcata (Airplane
Plant; Propeller Plant; Scarlet Paintbrush); C. argentea; C. multicava
(spoon shaped leaves, white flowers tinted w/ red); C. lactea (9 in. shrubby,
white flowers); C. sarcocaulis; C. arborescens (Silver Dollar Plant); C.
ovata (Jade Plant; Money Plant; Chinese Rubber Plant); C. pyramidalis;
C. shmidtii; C. tetragona; C. 'Morgan's Beauty'; C. 'Morgan's Pink'; C.
streyi; C. muscosa; C. lycopodioides (Watch Chain; Toy Cypress); C. perforata
(String of Buttons); C. rupestris (Buttons-on-a-String).
Information from: http://www.botany.com