If you’re looking for a plant for your garden that will come back year after year, is easy to care for and suitable for a variety of growing conditions, coral bells (Heuchera) just might be the plant for you. It’s also known by the common names alum root and rock geranium.
Heuchera are semi-evergreen perennials that are native to eastern and central North America. They can be grown in United States Department of Agriculture Plant Hardiness Zones 4 to 9, with some varieties hardy to Zone 3.
They grow in a well-behaved, mounding shape. Depending on the variety, they can grow from 12 to 36 inches in diameter and 6 to 24 inches high.
Heuchera leaves are by far this plant’s star feature. Foliage comes in a variety of shapes and textures. It can be solid colored or variegated, smooth, bumpy or ruffled. Colors range from shades of red, pink and burgundy, to neon green, caramel, silver and nearly black.
Tiny, bell-shaped flowers in shades of white, red and pink appear during the summer months on thin stems that grow above the foliage. They attract pollinators such as bees and hummingbirds.
For the best foliage color and flowers, plant heuchera in part sun/part shade (4 to 6 hours of direct sun a day). Most varieties do fine in conditions from full shade (less than 4 hours of direct sun) to full sun (at least 6 to 8 hours direct sun). Check the plant’s tag for a particular variety’s needs.
If you notice foliage showing signs of sun scald, consider moving the plant to a more compatible location in your garden and remove any damaged leaves.
Heuchera can be used as a ground cover or to add interest to garden beds, borders and containers all season long. Those grown in containers may need added insulation to protect against winter temperatures. As an alternative, they can be planted in-ground and repotted the following spring.
They can add a burst of color to a shade garden and make good companions for hostas (Hosta), bleeding hearts (Dicentra spectabilis or ferns-like ostrich fern (Matteuccia struthiopteris). They’re equally at home in a part-sun or full sun garden, along with lady’s mantle (Alchemilla mollis) and day lilies (Hemerocallis). Check the care tag for the variety you select.
Plant one variety of heuchera in a group for a bold statement of color, or mix varieties to highlight the contrast in foliage color and leaf texture.
Heuchera can be planted in spring or fall. They prefer rich, well-drained soil but will adapt well to all but heavy clay soil. Amend heavy clay soil to improve drainage.
Heuchera should be planted with the crown at the same soil level as in the pot. Water well when planting, and water as needed until established, particularly if conditions are hot or dry.
Because of the plant's shallow root system, the crown may lift from the ground during freeze-and-thaw cycles in winter. Applying a generous layer of mulch around plants in the fall can help reduce the chance of this happening. If you notice plants have heaved out of the ground over the winter, replant in spring as soon as the soil is workable.
Divide mature plants every 3 to 4 years by separating clumps in springtime, being sure each piece has a good amount of roots and foliage.
Heuchera are considered deer and rabbit resistant, but keep in mind that during lean times, these garden visitors will feed on almost any plant.
For answers to your home gardening questions, please contact the UVM Extension Master Gardener Helpline at https://go.uvm.edu/gardenquestion.