Plant, Tree & Shrub Library

Other Names:  Coralbells, Alumroot

Description:

Dark and moody deep purple-black, smooth and shiny foliage wont fade in the sun; tall flower spikes of creamy white appear during the early summer; flowers are suitable for cutting; great for color contrast in beds, borders and containers; low maintenance

Ornamental Features

Obsidian Coral Bells features dainty spikes of creamy white bell-shaped flowers rising above the foliage from late spring to early summer. Its attractive crinkled lobed leaves emerge burgundy in spring, turning black in color with curious deep purple undersides the rest of the year.

Landscape Attributes

Obsidian Coral Bells is a dense herbaceous evergreen perennial with tall flower stalks held atop a low mound of foliage. Its relatively fine texture sets it apart from other garden plants with less refined foliage.

This is a relatively low maintenance plant, and should be cut back in late fall in preparation for winter. It is a good choice for attracting hummingbirds to your yard. It has no significant negative characteristics.

Obsidian Coral Bells is recommended for the following landscape applications;

• Mass Planting
• Rock/Alpine Gardens
• Border Edging
• General Garden Use
• Groundcover
• Container Planting

Planting & Growing

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. As an evegreen perennial, this plant will typically keep its form and foliage year-round.

This plant performs well in both full sun and full shade. However, you may want to keep it away from hot, dry locations that receive direct afternoon sun or which get reflected sunlight, such as against the south side of a white wall. 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. It can be propagated by division; however, as a cultivated variety, be aware that it may be subject to certain restrictions or prohibitions on propagation.

Obsidian Coral Bells is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. With its upright habit of growth, it is best suited for use as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden. Be aware that in our climate, most plants cannot be expected to survive the winter if left in containers outdoors, and this plant is no exception. Contact our experts for more information on how to protect it over the winter months.