Crassula rupestris is a succulent perennial sub-shrub native to South Africa. This cute little plant will reach up to 3 feet (1 m) tall in nature, but in containers it stays much smaller and usually reaches a height of only 6-12 inches (15-30 cm) tall and wide. The small, thick leaves are ovate to lanceolate and clasp the stem in opposite directions. With great age, the leaves can reach up to 1 inch (2.5 cm) long. In the summer in Africa, this plant takes on wonderful red and yellow colors as the plant goes dormant. They are slow growing and make excellent container plants. They are hardy in the landscape in USDA zones 9-11.
Blooming: In nature, the plants bloom in June-September (presumably six months earlier in South Africa). They have small pink flowers that are very showy.
Culture: Crassula rupestris need full sun to partial shade, with a well drained soil mix. We grow ours under 25% shade all year long and we never get the color change as plants in nature do. In the greenhouse, we use a soil mix consisting of 1 part peat moss to 1 part loam to 2 parts sand. We add small gravel to ensure good drainage. The plants are well watered and allowed to dry thoroughly before watering again. We fertilize the plant once during the growing season with a balanced fertilizer diluted to 1/2 the strength recommended on the label. This plant is very drought tolerant and too much water will tend to rot the stems at ground level and smother the roots. During the dormant period, we water only enough to keep the leaves from shriveling.
Propagation: Crassula rupestris is best propagated from cutting. The seed is very fine and looks like dust. Seed should be surface sown on moist sand to germinate.
Crassula rupestris was featured as Plant of the Week October 3-9, 2008.
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Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.