Arborvitae vs Pulmonaria 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.
Pulmonaria
Pulmonaria officinalis
Pulmonaria officinalis, commonly known as lungwort, is a herbaceous perennial plant native to Europe. It is characterized by its distinctive spotted leaves, which are typically green with white or silver markings. The plant forms a low-growing clump and produces clusters of small, bell-shaped flowers that change color from pink to blue as they mature. Lungwort is primarily grown outdoors in gardens for its attractive foliage and early spring blooms. It thrives in shady, woodland-like conditions. While it can be attempted indoors, it requires very specific conditions and is generally not well-suited for indoor cultivation.
Quick Plant Comparison
| Feature | Arborvitae | Pulmonaria |
|---|---|---|
| Light | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth. | Partial shade to full shade. Avoid direct sunlight, especially during the hottest part of the day. |
| Watering | Every 1-2 weeks, depending on weather and soil drainage. | Every 3-5 days, depending on environmental conditions |
| Humidity | 40-60% | 40-60% |
| Temperature | 10-24°C | 13-18°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | Rarely grown indoors; outdoors 9-18 meters | 20-30 cm (indoors unlikely to reach this) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining, slightly acidic soil. A mix of loam, sand, and peat moss is suitable. | Well-draining, humus-rich soil |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes monthly (outdoor) | 15 minutes weekly (outdoor) |
🔬 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. |
Pulmonaria
| Scientific Name | Pulmonaria officinalis |
|---|---|
| Family | Boraginaceae |
| Native To | Europe |
| Also Known As | Lungwort, Common Lungwort, Jerusalem Cowslip, Spotted Dog |
| Leaves | The leaves of Pulmonaria are ovate to lance-shaped, typically 10-25 cm long, and have a rough texture. They are usually green with distinctive white or silver spots, although some varieties have more pronounced variegation. The spots are caused by air pockets within the leaf tissue. |
| Flowers | Pulmonaria produces clusters of small, bell-shaped flowers in early spring. The flowers are typically pink when they first open, then gradually turn blue as they mature. This color change is due to changes in pH levels within the petals. Flowering is unlikely indoors. |
📏 Size & Growth — Plant Comparison
Arborvitae
Pulmonaria
🌱 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.
Pulmonaria
Methods: Division, Seed
Difficulty: Moderate
Tips: Divide established clumps in early spring or fall. Sow seeds in a cold frame in autumn or early spring.
✨ 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
Pulmonaria
The most unique characteristic of Pulmonaria is its spotted leaves, which provide visual interest even when the plant is not in bloom. The flowers also change color from pink to blue as they mature, adding another layer of appeal. It is also relatively deer-resistant.
- ✓ Attracts pollinators to your garden.
- ✓ Adds visual interest with its unique spotted foliage.
- ✓ Provides early spring color to shady areas.
- ✓ Deer-resistant, protecting your garden from damage.
- ✓ Can be used as a ground cover in woodland gardens.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Arborvitae
Pulmonaria
🌞 Light Requirements
Arborvitae
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth.
Low light tolerant: ❌ No
Pulmonaria
Partial shade to full shade. Avoid direct sunlight, especially during the hottest part of the day.
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.
Pulmonaria
Keep the soil consistently moist, but not waterlogged. Water when the top inch of soil feels dry to the touch. Overwatering can lead to root rot, while underwatering can cause the leaves to wilt and brown. Ensure good drainage.
🌡️ Temperature & Humidity
Arborvitae
Temperature: 10-24°C
Humidity: 40-60%
Pulmonaria
Temperature: 13-18°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.
Pulmonaria
Pulmonaria officinalisExperienced gardeners looking for a shade-loving plant with unique foliage and early spring blooms in an outdoor garden.
✅ Choose This Plant If...
- You want a shade-loving plant with unique spotted foliage.
- You appreciate early spring blooms that attract pollinators.
- You are looking for a deer-resistant plant for your garden.
- You enjoy plants with interesting color-changing flowers.
- You have a cool, shady spot in your garden that needs some color.
❌ Skip This Plant If...
- You are looking for an easy-to-grow indoor plant.
- You have pets that might ingest the plant.
- You do not have a cool, shady outdoor space.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.
💡 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.
Pulmonaria Care Tips
Pulmonaria is primarily an outdoor plant that prefers cool, shady conditions. Indoor cultivation is challenging due to the need for consistent moisture, high humidity, and cool temperatures. It is prone to fungal diseases and root rot if not properly cared for indoors. Requires very bright indirect light, which is difficult to provide indoors.
- Provide consistent moisture, especially during dry periods.
- Protect from direct sunlight to prevent leaf scorch.
- Amend the soil with compost or leaf mold to improve drainage and fertility.
- Divide plants every few years to prevent overcrowding.
- Monitor for pests and diseases regularly.
⚠️ Common Problems & Solutions — Plant Care Comparison
Arborvitae
Pulmonaria
❓ 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.
Pulmonaria
What are the light requirements for Pulmonaria?
Pulmonaria thrives in partial to full shade. In regions with hot summers, full shade is essential to prevent leaf scorch. Morning sun is tolerated, but avoid direct afternoon sun. The ideal location receives dappled sunlight throughout the day. Insufficient light can result in fewer blooms and less vibrant foliage.
How do I care for Pulmonaria?
Pulmonaria prefers partial to full shade, especially in warmer climates. Direct sunlight can scorch the leaves. The ideal location is one that receives morning sun and afternoon shade. Plant in well-draining, humus-rich soil that retains moisture. Water regularly, especially during dry periods, keeping the soil consistently moist but not soggy.
How do I propagate Pulmonaria?
Pulmonaria is most easily propagated by division in early spring or fall. Carefully dig up the plant and separate the root ball into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions in well-draining, humus-rich soil. Keep the soil consistently moist until the plants are established.
Last updated: May 4, 2026 — Plant care data reviewed and verified by our editorial team.