The common name "coral bells" is used for several species in the Heuchera genus, comprising hundreds of varieties and hybrids. Coral bells is a traditional perennial foliage plant, with new varieties introduced every year. Native to North America, the plants form round mounds with a woody rootstock or crown at their base and small bell-shaped flowers that begin in spring or early summer on the tall stems. Rich in nectar, the flowers attract hummingbirds and butterflies, plus make nice cut blooms. Their leaves are rounded, lobed, hairy, and evergreen or semi-evergreen, depending on the climate. Besides traditional green-leaved coral bells, newer varieties have leaves in shades of purple, rose, lime green, gold, and more.
Coral bells are best planted in late fall or early spring and will grow at a moderate pace, making them a great option for woodlands, rock gardens, containers, borders, and ground covers. But they are short-lived perennials; unless divided regularly, they will die out in a few years.
|Common Name||Coral bells, alumroot, rock geranium|
|Botanical Name||Heuchera spp.|
|Mature Size||8–18 in. tall, 12–24 in. wide|
|Sun Exposure||Full, partial|
|Soil Type||Rich, moist but well-drained|
|Soil pH||Acidic, neutral|
|Bloom Time||Spring, summer|
|Flower Color||Red, white, pink, orange|
|Hardiness Zones||4a–9a (USDA)|
|Native Area||North America|
Watch Now: How to Take Care of Coral Bells (Heuchera)
Coral Bells Care
Coral bells is a fairly easy plant to grow in a semi-shady location in well-draining, organically rich soil. Some hybrid cultivars can do quite well in full sun—though they will require more water to thrive. This plant is a good choice for providing color in a landscape filled with shade trees.
While coral bells don't need much maintenance, you can cut back the entire flower stalk after flowering to put the plant's energy into growing more leaves. If the leaves get a bit ragged looking, especially after winter, cut them back and new growth should fill in quickly. Deadheading the faded flowers regularly will help ensure repeated blooming all summer and into fall.
Most varieties of coral bells do best in partial shade, especially in hotter climates. Their color can become washed out if they're kept in full sun, and too much light can cause their leaves to scorch. Keep in mind, that coral bells planted in damp shady areas can be prone to fungal diseases—if your plants start having problems, it's best to move them to a drier site.
Coral bells prefer humus-rich soil with a neutral to slightly acidic soil pH, somewhere between 6.0 and 7.0. Good drainage is a must, especially in shaded areas, as sitting in the damp soil will cause the crown of the plant to rot.
This plant has medium water needs and likes consistently moist soil. Established plants will tolerate some drought, but an inch of water per week is the best way to keep them happy. If you grow your coral bells in full sun, plan to give them extra water—their shallow roots will need extra moisture during hot, sunny days.
Temperature and Humidity
Coral bells are hardy in USDA hardiness zones 4a to 9a, although the exact hardiness range does depend on the variety you're growing and its parentage. Some Heucheras are only hardy to zone 7, while others do well in cold but don't perform well south of zone 6. Most coral bells prefer relatively dry air, but Heuchera villosa, a native of the southeastern U.S., thrives on both heat and high humidity.
In regions with frigid winters, coral bells crowns can heave above the soil line in the winter. Winter mulching will help prevent the freezing/thawing cycle that pushes the plants up, and you should check periodically to make sure the roots are not exposed.
Feed coral bells in the spring with a one-half-inch layer of compost or a light amount of slow-release fertilizer. This plant has light feeding needs; you should avoid heavy applications of quick-release fertilizers, as this will inhibit flowering. Container-grown coral bells benefit from feeding with a water-soluble fertilizer to replenish nutrients that leach from the soil. For the amount, follow the product label instructions.
Types Coral Bells
Several different species of Heuchera, including H. americana, H. sanguinea, H. villosa, and H. parviflora, are commonly sold in the trade, along with named cultivars of each species. H. sanguina is regarded as the best species for ornamental purposes and is the one most often sold as coral bells; the other species are more often known as alumroot. The species plants have medium-green leaves, but 'Dale's Strain' and 'Purple Palace' were two of the first cultivars to offer reddish bronze and purple foliage.
But even more popular are the many named cultivars derived from cross-species hybridization. These often simply carry the Heuchera label. The exact parentage of hybrids is sometimes lost, but H. americana and H. sanguina are thought to be the most common parent species. The most notable differences between varieties can be seen in their foliage color and texture variations. There are dozens of these cultivars, including:
- Heuchera 'Autumn Leaves': As hinted at by its name, the leaves on this hybrid variety change color through the seasons, from red to caramel to ruby.
- Heuchera 'Chocolate Ruffles': This hybrid variety has ruffled leaves with rich chocolaty color on the top and deep burgundy on the bottom.
- Heuchera 'Green Spice': This hardy hybrid has large green leaves that are veined in maroon.
- Heuchera 'Marmalade': Another frilly hybrid cultivar, the leaves on this version appear in shades ranging from umber to deep sienna.
- Heuchera 'Citronelle; This variety has bright yellowish-green leaves that are excellent for brightening shady areas.
- Heuchera 'Electric Lime': This striking variety has bright green leaves with blood-red veins.
- Heuchera 'Fire Chief': Bright red spring foliage slowly deepens to crimson as the season progresses.
Propagating Coral Bells
Coral bells is most often propagated by dividing the root clumps. Either fall or spring division will work, though many gardeners prefer fall. Heuchera plants often produce small offsets around the parent plant, and it's an easy matter to carefully dig up these offsets and replant them. The root crowns of the divisions should be planted so they are just barely covered with soil.
Heuchera plants are fairly short-lived, and this division should be done every three or four years to prevent them from dying out. To propagate mature plants:
- Dig up the entire root clump with a shovel in fall or spring.
- Cut the root clump into pieces, each having several growth shoots. The woody center portion can be discarded.
- Prepare new planting sites by blending in plenty of compost or peat moss, then replant the divisions, just barely covering the root crowns.
How to Grow Coral Bells From Seed
You can start coral bells from seed, but results can be irregular if you are collecting seeds from hybrid plants. Commercial seeds will produce more predictable results. If you want to propagate plants by collecting seeds, it's best to start with pure species plants rather than nursery hybrids. Pure species are easiest to obtain from specialty nurseries or online retailers.
When starting the seed, sprinkle the seed on the surface of the soil in late fall or early spring, making sure not to cover the seed as they need light to germinate. You can also start seeds indoors a couple of months before you plan to transplant. Coral bells seeds take two to eight weeks to germinate.
Once established, harden off the plants for 10 days, then transplant the seedlings outdoors after all danger of frost has passed. You can plant container-grown coral bells any time after the danger of frost has passed. Keep them well-watered their first year—other than that, they shouldn't require more than some relief from the extreme heat and rich, well-draining soil.
Potting and Repotting Coral Bells
Although it's not typical to grow perennials such as coral bells in containers, it certainly can be done, and this plant does quite well when grown that way. Choose a container that has good drainage and a potting mix that drains freely. When grown in containers, keep the root crown slightly higher than the soil level. If you want to overwinter these plants in pots, they will need to be moved to a protected location to shield them from cold winter temperatures. During the winter months, withhold water and allow the plants to go dormant.
While the spectacular foliage might tempt you to try growing coral bells as a houseplant, they do not lend themselves to this use. These woodland plants can do fine in outdoor containers where they receive a dormant period over winter, but they rarely are successful as permanent indoor houseplants.
In warmer climates, this plant often remains evergreen through the winter. Because the roots are shallow, coral bells can be prone to winter root heaving in colder climates. A light mulch over the plants can prevent this. In other regions, overwintering simply involves cleaning up plant debris to prevent fungi from overwintering.
Common Pests & Plant Diseases
Coral bells is usually a fairly carefree plant, but it can be affected by various fungal diseases, including powdery mildew, rust, and bacterial leaf spot.
Potential insect problems include weevils and foliar nematodes. The larvae of the black vine weevil can bore into the crowns and roots of coral bells in late summer or early fall, causing infected plants to wilt and droop. You should be able to see the larvae on the plant and remove them by hand and destroy them. If an infection persists, treat your plants with a mild insecticide or neem oil.
How to Get Coral Bells to Bloom
Sparse blooming is usually not concerning with these plants, since it is the foliage color that is of greatest appeal. But the stems of airy, delicate red or pink flowers certainly do have ornamental merit, and if planted in good growing conditions, you can expect repeated blooms from late spring into fall. Avoid overfeeding these plants, which can hinder blossoming as it stimulates foliage development. And some varieties bred to be sun-lovers may not bloom well if they are planted in deep shade.
Common Problems With Coral Bells
Coral bells are generally quite easy to grow, but there are some common cultural problems you may encounter:
Most varieties of coral bells are not keen about growing in full sun, and they may exhibit burned, scorched leaves if they get too much sun, especially in climates with hot summers. Giving plants extra water during hot spells can minimize this scorching.
Plants Die Out After a Few Years
It's sometimes disappointing when a thriving coral bells plant suddenly declines, but this is rather normal, as these are short-lived perennials that usually live only four or five years. You can prolong the lifespan by dividing root clumps every three or four years, which will provide new plants to continue the lineage.
Plants Lift Out of the Ground
Coral bells have shallow root systems with crowns that are slightly exposed. In cold climates, frost heaving can push them out of the ground entirely, which will require you to replant them. A layer of mulch applied just after the ground freezes may help prevent heaving due to repeated freeze-thaw cycles.
How should I use coral bells in the landscape?
Coral bells make wonderful edging plants and put on a show when planted in groups. Their foliage is vibrant and saturated and is great for playing up the colors of nearby flowers in the garden—darker purple leaves can make yellow flowers glow, while butterscotch-colored leaves can bring out the tones of simple green leaves.
Are there any coral bells varieties that work well in hot climates?
The more heat-tolerant cultivars often have Heuchera villosa in their parentage, which is a notably heat-tolerant species. Gardeners as far south as zone 9 usually have success with varieties based on this species. Two excellent cultivars known for their heat tolerance are ‘Caramel’ and ‘Citronelle’. H. villosa is a native plant in the southeastern U.S. and hardy to zone 7.
How about cold-winter gardens—are there any varieties that work in zone 3?
Heuchera sanguinea and its direct cultivars are considered hardy to zone 3. But you will need to make sure of the parentage, as many nursery hybrids have other species among their parents, which are not as cold-hardy. To buy pure H. sanguinea plants, you may need to shop at a specialty nursery.
Coral Bells Heuchera. The Connecticut Agricultural Experiment Station.
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Heuchera villosa. North Carolina State University Extension Service
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Heuchera—Coral Bells. Gardenia
Dividing perennials. University of Minnesota Extension.
Balogh, Anne. A Guide to Growing Heuchera Plants (Coral Bells). Garden Design.
Heuchra 'Amber Waves'. Missouri Botanical Garden.
Black Vine Weevil in Heuchera. University of British Columbia Botanical Garden.
Heuchera—Coral Bells. Clemson Cooperative Extension.