Arborvitae vs Bells of Ireland Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Arborvitae
Thuja occidentalis
Thuja occidentalis, commonly known as American Arborvitae, is a coniferous evergreen tree or shrub. It typically grows outdoors to a height of 30-60 feet, forming a dense, pyramidal shape. The foliage consists of scale-like leaves arranged in flattened sprays. While valued for its use in hedges, screens, and ornamental plantings in landscapes, it is not naturally suited for indoor environments due to its high light and humidity requirements and large size. People grow it for its attractive foliage, fast growth, and tolerance of various soil conditions.
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.
Quick Plant Comparison
| Feature | Arborvitae | Bells of Ireland |
|---|---|---|
| Light | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth. | Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily. |
| Watering | Every 1-2 weeks, depending on weather and soil drainage. | Outdoors: 2-3 times per week, depending on weather. Indoors: Every 5-7 days, depending on light and humidity. |
| Humidity | 40-60% | 40-60% |
| Temperature | 10-24°C | 15-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Fast |
| Max Height | Rarely grown indoors; outdoors 9-18 meters | Indoors: 0.6-1 meter (2-3 feet). Outdoors: 0.6-1 meter (2-3 feet) |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining, slightly acidic soil. A mix of loam, sand, and peat moss is suitable. | Well-draining potting mix or garden soil. A mix of potting soil, perlite, and vermiculite is suitable. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes monthly (outdoor) | 30 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Arborvitae
| Scientific Name | Thuja occidentalis |
|---|---|
| Family | Cupressaceae |
| Native To | Eastern North America |
| Also Known As | American Arborvitae, Eastern Arborvitae, White Cedar, Swamp Cedar |
| Leaves | Scale-like, flattened, and arranged in overlapping sprays. Typically bright green, but can turn bronze in winter. Aromatic when crushed. |
| Flowers | Inconspicuous flowers that are rarely seen. Primarily grown for its foliage. |
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. |
📏 Size & Growth — Plant Comparison
Arborvitae
Bells of Ireland
🌱 Propagation — Comparing Plant Growth
Arborvitae
Methods: Stem cuttings, Seed
Difficulty: Moderate
Tips: Take semi-hardwood cuttings in late summer. Dip in rooting hormone and plant in well-draining soil. Keep moist and provide indirect light.
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.
✨ Benefits & Features — Comparing Plant Value
Arborvitae
Its dense, evergreen foliage provides year-round privacy and screening. It is relatively fast-growing compared to other evergreens. The scale-like leaves are aromatic when crushed.
- ✓ Provides privacy and screening.
- ✓ Offers year-round greenery.
- ✓ Attracts birds and wildlife.
- ✓ Relatively low-maintenance once established.
- ✓ Can be used to create formal hedges or natural screens.
- ⚠️ Toxic to pets
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
📅 Maintenance Schedule — Plant Care Comparison
Arborvitae
Bells of Ireland
🌞 Light Requirements
Arborvitae
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth.
Low light tolerant: ❌ No
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
💧 Watering Needs
Arborvitae
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. In containers, ensure proper drainage. Signs of underwatering include browning foliage and drooping. Overwatering symptoms include yellowing leaves and a musty smell from the soil.
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.
🌡️ Temperature & Humidity
Arborvitae
Temperature: 10-24°C
Humidity: 40-60%
Bells of Ireland
Temperature: 15-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Arborvitae
Thuja occidentalisLandscapers and gardeners looking for a fast-growing evergreen for hedges, screens, or ornamental plantings in outdoor settings.
✅ Choose This Plant If...
- You need a fast-growing evergreen screen or hedge for your yard.
- You want to attract birds to your garden.
- You have well-draining soil and plenty of sunlight.
- You live in a climate with cold winters and hot summers.
- You want a low-maintenance plant once established outdoors.
❌ Skip This Plant If...
- You live in an apartment or have limited outdoor space.
- You have pets that might ingest the foliage.
- You cannot provide at least 6 hours of direct sunlight daily.
- You are looking for an easy indoor plant.
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.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Arborvitae has moderate growth, while Bells of Ireland grows fast.
💡 Pro Tips For Comparing These Plants
Arborvitae Care Tips
American Arborvitae is primarily an outdoor plant and is very difficult to maintain indoors due to its high light and humidity requirements. It needs full sun and well-draining soil. Indoor cultivation is not recommended.
- Plant in well-draining soil to prevent root rot.
- Water deeply during dry periods, especially in the first year.
- Prune regularly to maintain shape and density.
- Protect from heavy snow and wind in winter.
- Monitor for pests and diseases and treat promptly.
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.
⚠️ Common Problems & Solutions — Plant Care Comparison
Arborvitae
Bells of Ireland
❓ Frequently Asked Questions — Comparing These Plants
Arborvitae
What are the light requirements for Arborvitae?
Arborvitae thrives in bright, indirect light. Direct sunlight can scorch its delicate foliage, so avoid placing it directly in front of south-facing windows. East- or west-facing windows provide optimal light conditions. If you notice the foliage becoming pale or sparse, it may indicate insufficient light. Supplement with artificial grow lights if natural light is limited, especially during winter months. Rotate the plant regularly to ensure all sides receive adequate light. Monitor the plant’s growth and adjust its position as needed to maintain healthy foliage. Insufficient light can lead to legginess and poor growth.
How do I care for Arborvitae?
Indoor Arborvitae require bright, indirect light; avoid direct sunlight, which can scorch the foliage. Water thoroughly when the top inch of soil feels dry, ensuring proper drainage to prevent root rot. Maintain moderate humidity levels; consider using a humidifier or placing the pot on a pebble tray. Fertilize sparingly during the growing season (spring and summer) with a balanced, slow-release fertilizer. Repot every 2-3 years or when the plant becomes root-bound, using a well-draining potting mix. Prune regularly to maintain shape and remove any dead or yellowing foliage. Provide adequate air circulation to prevent fungal diseases. Monitor for pests such as spider mites and aphids, and treat promptly with insecticidal soap. Keep the plant in a stable temperature range, avoiding extreme fluctuations. Rotate the plant occasionally to ensure even growth. Dust leaves regularly to allow for better light absorption.
How do I propagate Arborvitae?
Arborvitae can be propagated through stem cuttings or air layering.
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.
Last updated: May 5, 2026 — Plant care data reviewed and verified by our editorial team.