Heucheras, once called alum roots, now more commonly known as coral bells, are adaptable easy-care perennials native to the United States, and have enjoyed an explosion of breeding and popularity in the last twenty years. In the Saxifragaceae family, the basal foliage resembles ruffled lettuces, and dainty bells rise on stalks called a thyrse, creating a candelabra effect. There are hybrid heucheras for sun or shade, in a rainbow of colors including lime, rust, bronze, silver, purple, and near black in solids and variegated varieties.
Hardy from zones 4-9, in warmer areas they retain that stunning color adding winter interest. Foliage can be six to 18 inches tall, with flowers up to two feet. The flowers, in white, pinks, and reds, are usually secondary to the foliage, but some cultivars offer showier flower displays. They tend to be disease-resistant, and unattractive to deer and rabbits.
Planting Coral Bells
Choose a spot with the appropriate sun level for your variety. Most prefer partial shade. Some are tolerant of full sun, while others suffer leaf scorch in the same conditions. In colder climates, they can take more sun if watered well. The ideal soil is well-drained, moist, with a pH that is neutral to slightly acidic. H. sanguinea and its cultivars tend to prefer neutral loam to acidic clay soils. Plant the crown at soil level or slightly above. Freeze/thaw cycles in spring can cause the crowns to heave out of the ground; mulch well in winter to prevent this, or replant gently and cover lightly with compost in spring. Divide clumps as needed every three years or so.
Watering Coral Bells
Coral bells need to be well watered the first couple of years in the garden to establish their roots. Their roots are shallow, so they need extra care during dry spells or heat waves. An inch of water per week should be sufficient. It’s best to water the soil rather than the leaves to prevent sun scorch; if you are not hand-watering, you can also water early in the morning. Established plants are fairly drought-resistant.
Heucheras are light feeders, so a dressing of compost in fall and spring should suffice for plants grown in the ground. In containers, a yearly spring application of slow-release fertilizer is recommended.
Pruning Coral Bells
Heuchera needs little in the way of pruning. You can promote new blooms by removing old flower stalks down to the base. In spring and fall, clear and remove any spent foliage, especially if you see signs of rust, in which case discard without composting. Divide clumps as needed every three years or so.
Coral bells are wonderful container subjects, because of their shallow roots, their potential for year-round color, and ease of care. Choose a well-draining soil mix and plant the crown at or slightly above soil level. Give plants slow-release fertilizer at planting time and yearly in spring, as well as a dressing of compost. In winter, protect from cold winds and rain, and stop watering while they are dormant.
Winter Care for Coral Bells
Top-dress the soil with compost in the fall, remove and dispose of any diseased foliage, and mulch crowns well to prevent heaving out of the ground after freezes. In early spring, trim off brown foliage. If growing in containers, protect from cold winds and rain, and stop watering while they are dormant.