Flowering Onion vs Pulmonaria Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Flowering Onion

Flowering Onion

Allium spp.

VS
Pulmonaria

Pulmonaria

Pulmonaria officinalis

Flowering Onion

Flowering Onion

Allium spp.

Flowering onions, or ornamental alliums, are bulbous perennials grown for their showy, spherical flower heads composed of numerous small, star-shaped flowers. They come in various sizes and colors, ranging from white and pink to purple and deep burgundy. Most are outdoor plants, thriving in gardens and borders. While some smaller varieties can be grown in containers, they are not ideally suited for indoor environments due to their high light requirements and dormancy needs. People grow them for their striking blooms, architectural interest, and ability to attract pollinators.

Amaryllidaceae Various species originate from different regions, including Europe, Asia, and North America.
✨ Features: Attracts pollinators, deer-resistant, long-lasting blooms.
📖 Read Complete Flowering Onion Guide
Pulmonaria

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.

Boraginaceae Europe
✨ Features: Attracts pollinators, deer-resistant, unique spotted foliage, color-changing flowers
📖 Read Complete Pulmonaria Guide

Quick Plant Comparison

Feature Flowering Onion Pulmonaria
Light Full sun (at least 6-8 hours of direct sunlight per day) Partial shade to full shade. Avoid direct sunlight, especially during the hottest part of the day.
Watering Every 1-2 weeks during the growing season, less frequently during dormancy. Every 3-5 days, depending on environmental conditions
Humidity 40-60% 40-60%
Temperature 15-25°C 13-18°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Variable, depending on the species, but typically 30-150 cm outdoors. Indoors, expect smaller sizes if grown in containers. 20-30 cm (indoors unlikely to reach this)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, such as a mix of potting soil, sand, and perlite. Well-draining, humus-rich soil
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 10 minutes weekly during the growing season. 15 minutes weekly (outdoor)

🔬 Botanical Information — Comparing These Plants

Flowering Onion

Scientific Name Allium spp.
Family Amaryllidaceae
Native To Various species originate from different regions, including Europe, Asia, and North America.
Also Known As Flowering Onion, Ornamental Onion, Allium
Leaves The leaves are typically linear or strap-shaped, often with a bluish-green hue. They emerge from the base of the plant and may wither as the plant flowers.
Flowers Flowering onions produce showy, spherical flower heads composed of numerous small, star-shaped flowers. The flowers come in various colors, including white, pink, purple, and burgundy. They rarely flower indoors due to light requirements.

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

Flowering Onion

Height Variable, depending on the species, but typically 30-150 cm outdoors. Indoors, expect smaller sizes if grown in containers.
Spread Variable, depending on the species, typically 15-30 cm. Some species can spread via bulb offsets.
Growth Rate Moderate
Growth Pattern Upright, with basal leaves emerging from the bulb and a tall flower stalk rising above the foliage. The flower heads are typically spherical and composed of numerous small flowers.

Pulmonaria

Height 20-30 cm (indoors unlikely to reach this)
Spread 30-45 cm (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern Pulmonaria grows as a low-growing clump, spreading slowly via rhizomes. It forms a dense mat of foliage and produces upright flower stalks in the spring.

🌱 Propagation — Comparing Plant Growth

Flowering Onion

Methods: Bulb offsets, Seed

Difficulty: Moderate

Tips: Separate bulb offsets from the main bulb in the fall and replant them. Sow seeds in the spring after a period of cold stratification.

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

Flowering Onion

Flowering onions are known for their distinctive spherical flower heads, which can range in size from a golf ball to a softball. They offer a unique architectural element in the garden and attract beneficial insects.

  • ✓ Attracts pollinators to the garden
  • ✓ Deer-resistant, protecting other plants
  • ✓ Adds architectural interest with unique flower shapes
  • ✓ Provides long-lasting blooms for visual appeal
  • ✓ Low-maintenance once established
  • ⚠️ 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

Flowering Onion

Repotting Not typically repotted if grown outdoors. If grown in containers, repot every 2-3 years in fresh soil.
Pruning Remove spent flower heads to prevent seed formation and encourage bulb growth. Cut back foliage after it has completely died back in the fall.
Fertilizing Balanced fertilizer (10-10-10) diluted to half strength, applied once in early spring and again after flowering.
Seasonal Care In spring, fertilize and water regularly as new growth emerges. In summer, enjoy the blooms. In fall, allow foliage to die back naturally and reduce watering. In winter, provide a dry, cool dormancy period.

Pulmonaria

Repotting Not applicable for indoor growing due to unsuitability. If grown in a container outdoors, repot every 2-3 years.
Pruning Remove dead or damaged leaves as needed. Cut back after flowering to encourage new growth.
Fertilizing Balanced liquid fertilizer diluted to half strength, applied once in early spring.
Seasonal Care In spring, fertilize and monitor for pests. In summer, provide shade and consistent moisture. In fall, divide plants if needed. In winter, protect from frost in colder climates.

🌞 Light Requirements

Flowering Onion

Full sun (at least 6-8 hours of direct sunlight per day)

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

Flowering Onion

Water thoroughly when the top inch of soil is dry. Avoid overwatering, which can lead to bulb rot. Reduce watering during dormancy. Signs of overwatering include yellowing leaves and a mushy bulb. Underwatering is indicated by wilting leaves and stunted growth.

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

Flowering Onion

Temperature: 15-25°C

Humidity: 40-60%

Pulmonaria

Temperature: 13-18°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Flowering Onion

Flowering Onion

Allium spp.
Care: Expert Time: 10 minutes weekly during the growing season. Beginner: No

Gardeners looking for striking, low-maintenance perennials to add architectural interest and attract pollinators to their outdoor spaces.

✅ Choose This Plant If...

  • You want a deer-resistant plant for your garden
  • You want to attract pollinators like bees and butterflies
  • You appreciate unique, globe-shaped flowers
  • You have a sunny garden space
  • You want a low-maintenance perennial that returns year after year

❌ Skip This Plant If...

  • You have pets that might ingest the plant
  • You don't have a sunny outdoor space
  • You are looking for an easy indoor plant
📍 Ideal Location: Outdoor garden beds, borders, or rock gardens with full sun exposure.
🎨 Style: Cottage, Naturalistic, Modern
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the bulbs, contain organosulfides that can cause gastrointestinal upset, anemia, and damage to red blood cells in dogs, cats, and horses. Symptoms include vomiting, diarrhea, weakness, and loss of appetite.
Pulmonaria

Pulmonaria

Pulmonaria officinalis
Care: Expert Time: 15 minutes weekly (outdoor) Beginner: No

Experienced 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.
📍 Ideal Location: Outdoor shade garden or woodland garden. Not suitable for typical indoor environments.
🎨 Style: Woodland, Cottage, Traditional
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Pulmonaria species contain pyrrolizidine alkaloids, which are toxic to dogs, cats, and horses. Symptoms include liver damage, abdominal pain, vomiting, and diarrhea. The entire plant is considered toxic.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ 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

Flowering Onion Care Tips

Flowering onions are primarily outdoor plants requiring full sun and well-draining soil. Indoor cultivation is challenging due to their high light needs and dormancy requirements. They are toxic to pets, so caution is needed if grown in areas accessible to animals. Regular watering and occasional fertilization are necessary for optimal growth.

  • Plant bulbs in well-draining soil to prevent rot
  • Provide full sun for optimal flowering
  • Water deeply but infrequently, allowing the soil to dry out between waterings
  • Fertilize in early spring and after flowering to promote bulb growth
  • Remove spent flower heads to encourage bulb development
❄️ Winter: Allow foliage to die back naturally. Provide a dry, cool dormancy period. Avoid overwatering.
☀️ Summer: Water regularly during dry periods. Provide support for tall flower stalks if needed. Monitor for pests and diseases.

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.
❄️ Winter: In colder climates, protect Pulmonaria from frost by mulching around the base of the plant. Reduce watering during the dormant season.
☀️ Summer: Provide shade during the hottest part of the day to prevent leaf scorch. Ensure consistent moisture, especially during dry periods.

⚠️ Common Problems & Solutions — Plant Care Comparison

Flowering Onion

Common Issues: Bulb rot, Onion white rot, Allium leaf miner, Aphids
Solutions: Ensure well-draining soil and avoid overwatering to prevent bulb rot. Remove and destroy infected plants to control onion white rot. Use insecticidal soap to control allium leaf miner and aphids.

Pulmonaria

Common Issues: Powdery mildew, Slugs and snails, Root rot, Leaf spot
Solutions: Improve air circulation and apply fungicide for powdery mildew. Use slug and snail bait or handpick pests. Ensure good drainage and avoid overwatering to prevent root rot. Remove affected leaves for leaf spot and apply fungicide if necessary.

❓ Frequently Asked Questions — Comparing These Plants

Flowering Onion

What are the light requirements for Flowering Onion?

Flowering Onions need ample sunlight to produce vibrant blooms. Aim for at least 6 hours of direct sunlight per day. If growing indoors, place them near a south-facing window where they can receive the most sunlight. Insufficient light can result in weak stems, pale foliage, and a lack of flowers. If natural light is limited, supplement with grow lights to provide the necessary intensity. Rotate the plant regularly to ensure even light exposure on all sides. Consider using a light meter to measure the light intensity and adjust the plant’s position accordingly.

How do I care for Flowering Onion?

Flowering Onions thrive in well-draining soil and require full sun to partial shade for optimal growth and flowering. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain away. Avoid overwatering, as this can lead to bulb rot. Fertilize during the growing season (spring and summer) with a balanced, slow-release fertilizer or a liquid feed diluted to half strength every 2-4 weeks to promote abundant blooms. Deadhead spent flowers to encourage further blooming and prevent seed production. Protect from frost in colder climates by mulching heavily or moving potted plants indoors. Repot every 2-3 years as needed, using a pot slightly larger than the previous one. Ensure good air circulation around the plants to prevent fungal diseases.

How do I propagate Flowering Onion?

Flowering Onions can be propagated through division, a relatively simple method. In the fall, after the foliage has died back, carefully dig up the bulbs. Separate the smaller bulblets from the main bulb. Replant the bulblets in well-draining soil, spacing them a few inches apart. Water thoroughly and mulch to protect them from frost. They may take a year or two to reach flowering size. Stem cuttings and keiki propagation are not applicable to Flowering Onions, as they are bulbous plants. Division is the primary method for increasing your stock of these beautiful plants. Ensure the bulblets have some roots attached for best results.

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: April 25, 2026 — Plant care data reviewed and verified by our editorial team.