Obsidian Coral Bells will grow to be about 10 inches tall at maturity extending to 24 inches tall with the flowers, with a spread of 12 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 10 inches apart. Its foliage tends to remain low and dense right to the ground. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 10 years.
This plant performs well in both part sun and full shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is somewhat tolerant of urban pollution. Consider covering it with a thick layer of mulch in winter to protect it in exposed locations or colder microclimates. This particular variety is an interspecific hybrid.