Bells of Ireland vs Blue Spruce Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Bells of Ireland
Moluccella laevis
Bells of Ireland is an annual flowering plant known for its tall spikes of vibrant green, bell-shaped calyces (modified leaves) that surround tiny, inconspicuous white flowers. It typically grows to a height of 2-3 feet. While it can be grown indoors, it's primarily an outdoor plant, often cultivated in gardens for its unique architectural form and long-lasting cut flowers. People grow it for its ornamental value, particularly in floral arrangements, where its bright green color adds a striking contrast.
Blue Spruce
Picea pungens
The Blue Spruce is a coniferous evergreen tree known for its distinctive blue-green needles and pyramidal shape. It is a large tree, typically growing outdoors to heights of 50-75 feet. Its needles are stiff and sharp, radiating in all directions from the branches. Cones are light brown and papery. It's primarily grown as an ornamental tree for its striking color and symmetrical form. It is not naturally an indoor plant and will struggle significantly indoors.
Quick Plant Comparison
| Feature | Bells of Ireland | Blue Spruce |
|---|---|---|
| Light | Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily. | Full sun (at least 6 hours of direct sunlight daily) |
| Watering | Outdoors: 2-3 times per week, depending on weather. Indoors: Every 5-7 days, depending on light and humidity. | Water deeply at planting and then as needed during dry periods, typically every 2-4 weeks once established. |
| Humidity | 40-60% | 30-50% |
| Temperature | 15-24°C | 10-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Slow To Moderate |
| Max Height | Indoors: 0.6-1 meter (2-3 feet). Outdoors: 0.6-1 meter (2-3 feet) | Not applicable indoors. Outdoors: 15-23 meters |
| Pet Safety | ✅ Safe | ❌ Toxic To Pets |
| Soil | Well-draining potting mix or garden soil. A mix of potting soil, perlite, and vermiculite is suitable. | Well-draining, slightly acidic soil. Avoid heavy clay soils. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly | 15 minutes monthly (mostly inspection for pests/disease) |
🔬 Botanical Information — Comparing These Plants
Bells of Ireland
| Scientific Name | Moluccella laevis |
|---|---|
| Family | Lamiaceae (Mint family) |
| Native To | Western Asia (Turkey, Syria, Caucasus) |
| Also Known As | Bells of Ireland, Molucca Balm, Shellflower |
| Leaves | The leaves are light green, oval to rounded in shape, and have slightly toothed edges. They are arranged oppositely along the stem and are generally inconspicuous compared to the prominent calyces. |
| Flowers | The actual flowers are small, white, and relatively insignificant, hidden within the larger green calyces. Flowering typically occurs in summer. |
Blue Spruce
| Scientific Name | Picea pungens |
|---|---|
| Family | Pinaceae |
| Native To | Rocky Mountains of the United States |
| Also Known As | Colorado Blue Spruce, Blue Spruce |
| Leaves | The needles are stiff, sharp, and approximately 1-inch long. They are four-sided and radiate in all directions from the branches. The color ranges from blue-green to silvery-blue, depending on the individual tree and the amount of wax coating on the needles. |
| Flowers | Blue Spruce trees produce small, inconspicuous flowers in the spring. These are not typically noticeable and are not the primary ornamental feature of the tree. It does not flower indoors. |
📏 Size & Growth — Plant Comparison
Bells of Ireland
Blue Spruce
🌱 Propagation — Comparing Plant Growth
Bells of Ireland
Methods: Seed
Difficulty: Moderate
Tips: Sow seeds indoors 6-8 weeks before the last frost or directly outdoors after the last frost. Seeds require light to germinate, so press them gently into the soil surface. Keep the soil consistently moist.
Blue Spruce
Methods: Seed, Cuttings, Grafting
Difficulty: Difficult
Tips: Propagation from seed is slow and requires stratification. Cuttings are difficult to root and grafting is the most reliable method, but requires specialized skills.
✨ Benefits & Features — Comparing Plant Value
Bells of Ireland
The most striking feature is the bright green, bell-shaped calyces that surround the tiny white flowers. These calyces persist long after the flowers have faded, providing extended ornamental value. It is not native to Ireland, despite its common name.
- ✓ Adds unique architectural interest to gardens and floral arrangements.
- ✓ Provides a vibrant green color that contrasts well with other flowers.
- ✓ Attracts pollinators like bees and butterflies.
- ✓ Symbolizes luck and good fortune.
- ✓ Can be dried and used in dried flower arrangements.
- 🐾 Pet Safe
Blue Spruce
The Blue Spruce is known for its striking blue-green needles, which are sharper and more rigid than those of other spruce species. The color intensity can vary among individual trees, with some exhibiting a more pronounced blue hue.
- ✓ Provides year-round visual interest
- ✓ Offers shelter and nesting sites for birds
- ✓ Can be used as a windbreak
- ✓ Relatively low-maintenance once established
- ✓ Increases property value.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Bells of Ireland
Blue Spruce
🌞 Light Requirements
Bells of Ireland
Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily.
Low light tolerant: ❌ No
Blue Spruce
Full sun (at least 6 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Bells of Ireland
Outdoors: Water regularly, keeping the soil consistently moist but not waterlogged. Indoors: Water thoroughly when the top inch of soil feels dry. Overwatering can lead to root rot; underwatering will cause wilting and browning of the calyces.
Blue Spruce
Water deeply when planting and during dry periods, especially when young. Established trees are relatively drought-tolerant. Overwatering can lead to root rot, so ensure well-draining soil. Signs of underwatering include browning needles and drooping branches. Signs of overwatering include yellowing needles and soggy soil.
🌡️ Temperature & Humidity
Bells of Ireland
Temperature: 15-24°C
Humidity: 40-60%
Blue Spruce
Temperature: 10-24°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Bells of Ireland
Moluccella laevisExperienced gardeners who want a unique and striking addition to their cut flower arrangements.
✅ Choose This Plant If...
- You want a unique and striking addition to your garden or floral arrangements.
- You enjoy the challenge of growing plants that require specific conditions.
- You are looking for a plant with a strong architectural presence.
- You want to attract pollinators to your garden.
- You need a long-lasting cut flower with a vibrant green color.
❌ Skip This Plant If...
- You have limited sunlight indoors and cannot provide supplemental lighting.
- You are a beginner gardener looking for an easy-to-grow plant.
- You live in a very hot or humid climate, which can increase the risk of fungal diseases.
Blue Spruce
Picea pungensLandowners with large properties seeking a striking ornamental evergreen tree.
✅ Choose This Plant If...
- You have a large outdoor space and want a striking evergreen tree
- You live in a climate with cold winters and full sun
- You want to attract birds and other wildlife to your property
- You appreciate the unique blue-green color of the needles
- You are looking for a relatively low-maintenance tree once established.
❌ Skip This Plant If...
- You live in an area with hot, humid summers
- You have limited space or are looking for an indoor plant
- You have pets that may ingest the needles
- You have poorly draining soil
- You dislike sharp needles.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Bells of Ireland has fast growth, while Blue Spruce grows slow to moderate.
💡 Pro Tips For Comparing These Plants
Bells of Ireland Care Tips
Bells of Ireland are best suited for outdoor gardens. Growing them indoors is challenging due to their high light requirements. Supplemental lighting is almost always necessary. Consistent watering and well-draining soil are crucial to prevent root rot. Requires careful monitoring for pests and diseases.
- Start seeds indoors 6-8 weeks before the last frost for earlier blooms.
- Provide well-draining soil to prevent root rot.
- Water regularly, especially during hot and dry weather.
- Fertilize every 2-4 weeks during the growing season with a balanced liquid fertilizer.
- Pinch back young plants to encourage bushier growth.
Blue Spruce Care Tips
Blue Spruce is an outdoor tree and is not suitable for indoor growing. It requires full sun, well-draining soil, and cold temperatures to thrive. Indoor attempts will likely result in a stressed and unhealthy plant.
- Plant in well-draining soil to prevent root rot
- Water deeply during dry periods, especially when young
- Mulch around the base of the tree to retain moisture
- Protect young trees from heavy snow and ice
- Monitor for pests and diseases regularly.
⚠️ Common Problems & Solutions — Plant Care Comparison
Bells of Ireland
Blue Spruce
❓ Frequently Asked Questions — Comparing These Plants
Bells of Ireland
What are the light requirements for Bells of Ireland?
Bells of Ireland crave sunlight. They need at least 6-8 hours of direct sunlight each day to produce vibrant green calyces and strong stems. Insufficient light can lead to leggy growth, pale coloring, and reduced blooming. When grown indoors, place them near a south-facing window where they can receive ample sunlight. If natural light is limited, supplement with grow lights. Rotate the plants regularly to ensure even light exposure on all sides. When starting seeds indoors, use grow lights to ensure healthy seedling development.
How do I care for Bells of Ireland?
Bells of Ireland require full sun, at least 6-8 hours daily, to thrive. Plant them in well-draining soil with a slightly acidic to neutral pH (6.0-7.0). Water regularly, keeping the soil consistently moist but not waterlogged, especially during hot weather. Fertilize every 2-3 weeks with a balanced liquid fertilizer during the growing season (spring and summer).
How do I propagate Bells of Ireland?
Bells of Ireland are typically propagated by seed.
Blue Spruce
What are the light requirements for Blue Spruce?
Blue Spruce requires bright, indirect light to thrive indoors. Insufficient light can lead to leggy growth and faded coloration. A south-facing window with sheer curtains is ideal, providing ample light without direct sun exposure, which can scorch the needles. Rotate the plant regularly to ensure even light distribution on all sides. If natural light is limited, supplement with grow lights to maintain healthy growth. Proper lighting is crucial for the development of the characteristic blue hue of the needles. Monitor the plant for signs of light stress, such as yellowing or browning needles, and adjust its placement accordingly.
How do I care for Blue Spruce?
Blue Spruce thrives indoors with proper care. Provide bright, indirect light, preferably near a south-facing window. Water thoroughly when the top inch of soil is dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels, especially during dry winter months. Fertilize sparingly during the growing season (spring and summer) with a balanced liquid fertilizer. Prune lightly to maintain shape and remove any dead or yellowing needles. Repot every 2-3 years into a slightly larger pot with well-draining soil. Ensure proper air circulation to prevent fungal diseases. Monitor for pests like spider mites and treat promptly if detected. Provide a stable environment with consistent temperature and humidity levels. Avoid placing near heat vents or drafts.
How do I propagate Blue Spruce?
Blue Spruce can be propagated through stem cuttings or air layering, though success rates can be low indoors. For stem cuttings, take 4-6 inch cuttings from new growth in late winter or early spring. Remove the lower needles and dip the cut end in rooting hormone. Plant the cutting in a well-draining potting mix and keep it consistently moist, but not waterlogged. Cover with a plastic bag to maintain humidity. For air layering, make a small incision on a branch and wrap it with moist sphagnum moss. Cover the moss with plastic wrap and secure it with tape. Keep the moss moist. Once roots develop, cut the branch below the rooted area and pot it in soil. Be patient, as rooting can take several months.
Last updated: April 22, 2026 — Plant care data reviewed and verified by our editorial team.