Plant coral bells (heuchera) in spring, which Iowa State says helps prevent winter heaving, or in fall (UVM; NC State says late fall or early spring). Set the crown at the same level as in the pot (UVM), space plants about 10 to 16 inches apart (Illinois), and choose part sun or part shade in rich, well-drained soil (UVM, NC State). Mulch fall plantings, because the shallow roots can be pushed up by freezing and thawing (UVM, Iowa State). Hardy in about zones 4 to 9, some to zone 3 (UVM).
Coral bells, also called alumroot, are mounding perennials grown mostly for their leaves, which come in red, burgundy, purple, caramel, lime, silver and near-black, often ruffled or patterned (UVM, NC State). Plants are 6 to 24 inches high and 12 to 36 inches wide depending on variety (UVM), and they send up thin stems of small bell-shaped flowers in summer that attract hummingbirds and bees (UVM, NC State). There are nearly 50 species, native to North America and the Russian Far East (NC State), and they are semi-evergreen to evergreen depending on the climate (UVM, NC State).
When to plant coral bells
| Timing | What the sources say |
|---|---|
| Spring | UVM plants in spring or fall, and NC State in early spring or late fall. Iowa State says spring planting helps avoid winter heaving, which coral bells are prone to |
| Fall | Possible (UVM, NC State), but Iowa State says perennials planted in late summer or early fall have small root systems and heave more easily. Mulch fall plantings well |
| Summer | Not a preferred window. Water new plants as needed until established, especially in hot or dry weather (UVM) |
| Dividing clumps | Every 3 to 4 years in spring (UVM). NC State says plants are usually short-lived unless divided about that often |
Our planting calendar shows your frost dates. In cold-winter areas, spring planting gives roots a full season before the first freeze-thaw cycles (GardenPal reasoning based on Iowa State). In mild-winter areas, fall planting is easier on the plants than summer heat; NC State notes that hairy alumroot (Heuchera villosa) and its hybrids handle heat and humidity best, and Illinois also calls the villosa hybrids more heat-tolerant.
How deep and far apart to plant coral bells
| Coral bells | |
|---|---|
| Depth | Crown at the same soil level as in the pot (UVM). Water well at planting (UVM) |
| Spacing | 10 to 16 in apart (Illinois); plants spread 12 to 36 in wide by variety (UVM), so check the tag |
| Light | Part sun or part shade, about 4 to 6 hours of direct sun, for best color and flowers; most handle full shade to full sun (UVM). NC State says many varieties color best in sun, but leaf scorch can occur in hot, dry sun |
| Soil | Rich, moist and well drained, amended with organic matter such as leaf compost (UVM, NC State). They dislike heavy clay, so amend it for drainage (UVM, NC State) |
| Mulch | A generous fall mulch reduces heaving (UVM) and protects the roots in winter (NC State) |
Watering, feeding and trimming
- Water until established, particularly in hot or dry weather (UVM).
- Deadhead spent flower stems to get more blooms through summer and into fall (NC State).
- Ragged leaves: NC State suggests removing all the tired foliage to push out fresh leaves. Remove sun-scalded leaves and move the plant to a better spot if scald keeps happening (UVM).
- Divide every 3 to 4 years in spring, keeping roots and leaves on each piece (UVM). Plants tend to be short-lived if never divided (NC State).
Coral bells in containers
UVM says coral bells work well in containers, but potted plants may need extra insulation in winter; as an alternative, plant them in the ground for winter and repot in spring. NC State also lists containers as a good use. Use a free-draining mix, since the plants dislike soggy soil (GardenPal note based on NC State and UVM).
Fall and winter: preventing heaving
- Why it happens: coral bells have shallow roots, and repeated freezing and thawing can lift the crown out of the ground, exposing it to cold, dry air (UVM, Iowa State).
- Mulch after the ground freezes. Iowa State suggests 3 to 4 inches of mulch over susceptible plants once the ground has frozen, usually by late November in Iowa, and removing it gradually in early spring, around mid-March there. Mulching too early can delay dormancy.
- Leave healthy plant debris in place over winter for extra insulation (Iowa State).
- If a plant heaves, replant it as soon as the soil can be worked in spring (UVM).
Pests and problems
NC State reports few problems overall. Possible diseases include powdery mildew, rust and bacterial leaf spot, and possible pests include weevils, Japanese beetles, mealybugs and foliar nematodes (NC State). Leaf scorch is common in hot, dry, sunny spots (NC State). Coral bells are considered deer and rabbit resistant, though hungry animals will eat almost anything in lean times (UVM).
Coral bells around the vegetable garden
Coral bells are border and edging plants rather than vegetable-bed plants, though their flowers do draw bees and hummingbirds (UVM, NC State). UVM pairs them with hostas, bleeding hearts and ferns such as ostrich fern in shade, and with lady's mantle and daylilies in sun. NC State uses them as edging and groundcover. See when to plant ferns, when to plant hostas, when to plant bleeding hearts and when to plant astilbe.
Frequently asked questions
When is the best time to plant coral bells?
Spring or fall (UVM). Iowa State says spring planting helps avoid winter heaving, which coral bells are prone to.
How far apart should coral bells be planted?
About 10 to 16 inches apart (Illinois); check the tag, since plants spread 12 to 36 inches wide (UVM).
How deep do you plant heuchera?
With the crown at the same soil level as in the pot (UVM).
Why do coral bells pop out of the ground in winter?
Their shallow roots get pushed up by freezing and thawing. Mulch 3 to 4 inches deep after the ground freezes (Iowa State) and replant heaved plants in spring (UVM).
Are coral bells safe for dogs and cats?
The ASPCA lists coral bells (Heuchera sanguinea) as non-toxic to dogs, cats and horses.
Do coral bells need sun or shade?
Part sun or part shade, about 4 to 6 hours of direct sun, gives the best color (UVM); many tolerate more sun or shade.
Enter your frost dates to time a spring or fall coral bells planting.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
- University of Vermont Extension, "Heuchera: a versatile landscape plant"
- NC State Extension Gardener Plant Toolbox, "Heuchera"
- University of Illinois Extension, "Coral bells"
- Iowa State University Extension, "Which perennials are most likely to be heaved up out of the ground in winter?"
- Iowa State University Extension, "What is frost heaving, and how do I prevent it?"
- ASPCA Animal Poison Control, "Coral bells"
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.