Heuchera 'Mahogany'
Common Name: coral bells
Type: Herbaceous perennial
Family: Saxifragaceae
Zone: 4 to 9
Height: 0.75 to 1.00 feet
Spread: 0.75 to 1.50 feet
Bloom Time: June to July
Bloom Description: Creamy white
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Showy
Leaf: Colorful

Culture

Heucheras are best grown in organically rich, humusy, medium moisture, well-drained soils in part shade. Parentage determines the best culture including optimum sun exposure. Unfortunately, the parentage of many hybrids in commerce today is unknown. Some hybrids will perform well in full sun, particularly in northern climates, but generally prefer some shade in the heat of the afternoon in southern locations. If grown in full sun, consistent moisture is very important. Scorch and general foliage decline may occur if soils are allowed to dry out. On the other hand, some hybrids perform well in shady locations, particularly if H. americana is a parent. Remove stems of faded flowers to encourage additional bloom. Foliage is essentially evergreen in warm winter climates. In cold winter climates such as St. Louis, the amount of retained foliage color in winter depends in large part upon the severity of the temperatures. A winter compost mulch applied after the ground freezes will help prevent root heaving. Divide clumps in spring every 3-4 years. Species plants may be grown from seed, but hybrids are usually divided in the garden.

Noteworthy Characteristics

Heuchera, commonly called coral bells or alumroot, is a genus consisting of about 55 species of evergreen to semi-evergreen herbaceous perennials which are all native to North America. Plants grow in a variety of different habitats including woodland areas, Appalachian seeps, prairies, rocky cliffs and alpine slopes. Plants range in size from dwarf alpine plants with flower spikes rising to only 5” tall to much larger woodland plants with flower spikes towering to 36” tall. Species plants are primarily native to the West, particularly in the Rocky Mountains, with a few species extending into northern Mexico. However, some important species are native to woodland areas in the East and Southeast.

The first significant hybrid heucheras were introduced into commerce around 1980, with the volume of new introductions increasing to almost avalanche proportions in recent years. Hybrids have now supplanted species plants in the marketplace. Species plants most frequently used in producing the hybrids of today are H. sanguinea, H. americana, H. micrantha, H. villosa and H. cylindrica. Leaves of hybrid plants are available in an expanded variety of colors including various shades of green, blue-green, violet, purple, maroon, bronze, silver-black, orange-yellow, yellow, or red, but often with a streaked, mottled or marbled variegation which sometimes includes bold contrasting veins. Flowers of hybrid plants are also available in a variety of different colors including various shades of white, pink, coral or red.

Genus name honors Johann Heinrich von Heucher (1677-1747), physician, botanist and medicinal plant expert at Wittenberg University, Germany.

Common name of coral bells is in reference to the red bell-shaped flowers produced by Heuchera sanguina. Common name of alum root is in reference to the medicinal use of some species plants as an astringent to stop bleeding.

‘Mahogany’ is a vigorous, clump-forming coral bells cultivar that is noted for its mahogany leaves. It typically grows in a dense basal mound to 8” tall and to 16” wide. Rounded, lobed, ruffled leaves emerge mahogany with purple tones in spring, but mature to mahogany-red by summer. Tiny creamy white flowers appear on slender stems rising above the foliage mound to 14” tall in summer. U. S. Plant Patent PP19,072 was issued on August 5, 2008.

Problems

No serious insect or disease problems. Frost heaving of roots may occur when winter temperatures fluctuate widely. Potential disease problems include powdery mildew, rust, and bacterial leaf spot. Potential insect problems include weevils and foliar nematodes.

Garden Uses

Mass as a ground cover or plant in groups. Rock gardens, borders and open woodland gardens. Effective as an edger along paths or walkways.