How to Grow Coral Bells 'Obsidian'

Wikimedia Commons

Coral Bells 'Obsidian'

Heuchera 'Obsidian'

flower

Coral Bells 'Obsidian' is a striking foliage plant prized for its deep burgundy-black leaves that maintain their rich color throughout the season. Delicate pink to coral-colored flowers appear on thin stems above the mounded foliage in late spring and early summer. This cultivar is a popular choice for adding dramatic color contrast to garden beds and containers.

When should you plant Coral Bells 'Obsidian' in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Coral Bells 'Obsidian' timeline →

Example Coral Bells 'Obsidian' timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Coral Bells 'Obsidian'

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Coral Bells 'Obsidian' blooms

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Coral Bells 'Obsidian' dates for your own zip code.

Growing Conditions

☀️
Sun: Partial shade to part sun, 3-6 hours of sunlight daily. Full shade in hot climates (zones 8-9). Best leaf color develops with some morning sun and afternoon shade.
💧
Water: Keep soil consistently moist but not waterlogged. Water deeply once or twice weekly depending on rainfall. Reduce watering in winter. Avoid overhead watering to prevent leaf spotting and fungal issues.
📏
Spacing: 18 inches
📅
Days to maturity: Blooms appear 60-90 days after planting; foliage reaches full size in 1-2 growing seasons
🌱
Planting depth: Plant so crown is at soil level; do not bury the crown. Container-grown plants should be planted at the same depth they were growing.

Soil

Type: Well-draining loamy soil
pH: 6.0-7.0
Amendments:
Compost Peat moss Perlite for drainage Leaf mold

Growing Zones

Find your zone →

Thrives in zones 4-9, with best performance in zones 5-8

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a

Sign up free to see if Coral Bells 'Obsidian' grows in your zone — and get a personalized planting timeline.

Get my Coral Bells 'Obsidian' timeline →

Growth Stages

1

Establishment

4-6 weeks

Young plant developing root system and establishing basal foliage rosette with dark burgundy leaves

Keep soil consistently moist. Mulch lightly around base but avoid piling mulch against the crown to prevent rot. Protect from strong wind.

2

Foliage Development

3-4 months

Mounded clump of deep burgundy-black leaves expands, creating dense ground cover. Foliage becomes increasingly vibrant and darker.

Remove any damaged or diseased leaves. Fertilize monthly with balanced fertilizer. Monitor for spider mites in dry conditions. Deadhead spent flowers if desired.

3

Flowering

4-8 weeks

Delicate panicles of small coral to pink flowers emerge on slender reddish stems above the foliage, creating an airy, contrasting display

Flowers typically appear May-July. Deadheading encourages longer blooming but is optional. Continue regular watering and avoid overhead irrigation.

4

Post-Bloom

Through winter dormancy

Flowers fade and seed heads dry. Foliage remains dark and ornamental throughout fall and winter in most zones.

Remove spent flower stems or leave for winter interest. In zone 3-4, apply 2-3 inches of mulch after first hard frost. Reduce watering as temperatures cool.

5

Spring Renewal

2-3 weeks

New foliage emerges from center of the crown, refreshing the plant for the new growing season

Remove old, dead leaves from previous year. Apply fresh compost around base without burying crown. Begin regular watering and fertilizing schedule.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Plants requiring full sun Drought-tolerant plants (e.g., ornamental grasses, sedums) Plants sensitive to moisture

Common Pests

  • Increase humidity and reduce dry conditions. Spray with water or neem oil. In severe cases, use miticide. Avoid sulfur sprays on heuchera.

  • Improve air circulation. Avoid overhead watering. Apply sulfur dust or fungicide if necessary. Remove affected leaves.

  • Ensure excellent drainage. Avoid waterlogging. Do not bury the crown. Remove and discard severely affected plants.

  • and

    Remove debris and mulch that provides hiding places. Use slug traps with beer or yeast. Apply diatomaceous earth around base.

  • Apply beneficial nematodes to soil. Hand-pick adults at night. Remove infested plants if damage is severe.

Uses

🌿

Dramatic Foliage Contrast

Ornamental

The deep burgundy-black leaves provide striking color contrast in shade gardens, functioning as a dark focal point among lighter-colored plants. Excellent for creating visual interest in borders and containers year-round. [source]

🏠

Cut Flower Arrangements

Household

The delicate coral-pink flower stems are lovely additions to small floral arrangements and can be used to create unique spring bouquets with their airy texture. [source]

🏠

Container and Landscape Design

Household

Excellent for mixed containers, rock gardens, and woodland gardens where its dark coloring and structural form add depth and sophistication to garden design. [source]

🦋

Pollinator Support

Wildlife

The delicate flowers attract bees, hoverflies, and other beneficial insects, providing early-season nectar and pollen when few other plants are flowering. [source]

💊

Traditional Herbal Uses

Medicinal

In traditional Native American medicine, Heuchera species have been used for astringent and anti-inflammatory properties, though 'Obsidian' is primarily grown ornamentally in modern gardens. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Coral Bells 'Obsidian' is primarily grown for ornamental foliage, not harvesting. Flowers can be cut for small arrangements when they appear in late spring or early summer. Cut stems above where leaves emerge. Remove spent flower stems anytime to maintain appearance and redirect energy to foliage production.

Fun Facts

  • 🌱 'Obsidian' is named for its resemblance to the dark volcanic glass obsidian, which was valued by Native Americans for tools and ornaments
  • 🌱 Coral Bells foliage color can deepen and become even more dramatically dark when exposed to cooler fall temperatures and morning sunlight, intensifying the burgundy-black pigmentation
  • 🌱 The genus Heuchera is native to North America and was commonly used by indigenous peoples; modern cultivars like 'Obsidian' have been selected for their dramatic colored foliage through decades of plant breeding

Gardening Terms

New to gardening? Learn about terms used in this guide:

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Coral Bells 'Obsidian' planting timeline

Tell us your zip code and we'll calculate exactly when to start Coral Bells 'Obsidian' seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Coral Bells 'Obsidian' timeline →