Common Myrtle vs Lobelia Cardinalis Plant Comparison

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

Common Myrtle

Common Myrtle

Myrtus communis

VS
Lobelia Cardinalis

Lobelia Cardinalis

Lobelia cardinalis

Common Myrtle

Common Myrtle

Myrtus communis

Myrtus communis, or Common Myrtle, is an evergreen shrub or small tree known for its aromatic foliage and attractive white flowers followed by dark berries. It is primarily an outdoor plant, thriving in warm climates. People grow it for its ornamental value in gardens, hedges, and topiary. It is also used in traditional medicine and culinary applications. While it can be brought indoors, it requires very specific conditions to thrive and often struggles to maintain its health and vigor.

Myrtaceae Mediterranean region
✨ Features: Aromatic foliage, attractive flowers and berries, used in traditional medicine and culinary applications.
📖 Read Complete Common Myrtle Guide
Lobelia Cardinalis

Lobelia Cardinalis

Lobelia cardinalis

Lobelia cardinalis, the Cardinal flower, is a striking herbaceous perennial native to North America. It features vibrant red, tubular flowers arranged on tall spikes, reaching heights of 2-4 feet. The plant has lance-shaped, green leaves that provide a lush backdrop to the brilliant blooms. It thrives in moist, well-drained soil and prefers partial shade to full sun. Cardinal flowers are primarily grown for their showy flowers, which attract hummingbirds and butterflies, making them a popular choice for gardens and naturalized areas. While it can be grown in containers, it is primarily an outdoor plant and may struggle indoors.

Campanulaceae North America
✨ Features: Attracts hummingbirds and butterflies, showy red flowers
📖 Read Complete Lobelia Cardinalis Guide

Quick Plant Comparison

Feature Common Myrtle Lobelia Cardinalis
Light Full sun to partial shade outdoors. Indoors, requires at least 6 hours of direct sunlight daily. Partial shade to full sun (at least 6 hours of direct sunlight)
Watering Outdoors: Every 7-14 days depending on weather. Indoors: Every 7-10 days, adjusting for humidity and light. Every 2-3 days, depending on weather and soil drainage
Humidity 40-60% 40-60%
Temperature 15-27°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Indoors: 0.6-1.2 meters (2-4 feet). Outdoors: 1-5 meters (3-16 feet) 0.6-1.2 meters (2-4 feet)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining potting mix with added perlite or sand. Rich, well-drained soil with plenty of organic matter
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Common Myrtle

Scientific Name Myrtus communis
Family Myrtaceae
Native To Mediterranean region
Also Known As Common Myrtle, True Myrtle
Leaves The leaves are small, oval-shaped, and glossy green. They are arranged oppositely on the stems and have a distinct aromatic scent when crushed.
Flowers Outdoors, it produces small, fragrant white flowers with prominent stamens in late spring to early summer. Indoors, flowering is less common but possible with optimal conditions.

Lobelia Cardinalis

Scientific Name Lobelia cardinalis
Family Campanulaceae
Native To North America
Also Known As Cardinal flower, Red lobelia
Leaves Lance-shaped, medium green leaves with serrated edges. Leaves are typically 7-15 cm long and arranged alternately along the stem.
Flowers Flowers are bright red, tubular, and arranged in a spike-like raceme. They bloom from mid-summer to early fall. It is highly unlikely to flower indoors due to light requirements.

📏 Size & Growth — Plant Comparison

Common Myrtle

Height Indoors: 0.6-1.2 meters (2-4 feet). Outdoors: 1-5 meters (3-16 feet)
Spread Indoors: 0.3-0.9 meters (1-3 feet). Outdoors: 1-3 meters (3-10 feet)
Growth Rate Moderate
Growth Pattern Outdoors, it grows as a dense, multi-stemmed shrub or small tree. Indoors, it tends to be more compact and can be trained into a small tree or topiary.

Lobelia Cardinalis

Height 0.6-1.2 meters (2-4 feet)
Spread 30-60 cm (1-2 feet)
Growth Rate Moderate
Growth Pattern Upright, clumping perennial with tall flower spikes.

🌱 Propagation — Comparing Plant Growth

Common Myrtle

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.

Lobelia Cardinalis

Methods: Seed, Division, Stem cuttings

Difficulty: Moderate

Tips: For seeds, cold stratify for 30 days before sowing. Divide clumps in spring or fall. Take stem cuttings in late spring and root in moist soil.

✨ Benefits & Features — Comparing Plant Value

Common Myrtle

Myrtus communis is known for its highly aromatic foliage, which releases a pleasant scent when crushed. It also produces attractive white flowers followed by dark berries, adding to its ornamental appeal.

  • ✓ Aromatic foliage provides a pleasant scent.
  • ✓ Attractive flowers and berries add visual interest.
  • ✓ Can be used in culinary applications.
  • ✓ Historically significant plant with cultural symbolism.
  • ✓ Can be shaped into hedges or topiary.
  • ⚠️ Toxic to pets

Lobelia Cardinalis

The vibrant red color and tubular shape of the flowers are specifically adapted to attract hummingbirds. It is a native plant that supports local ecosystems and provides habitat for wildlife.

  • ✓ Attracts pollinators (hummingbirds, butterflies)
  • ✓ Adds vibrant color to the garden
  • ✓ Provides habitat for wildlife
  • ✓ Native plant supports local ecosystems
  • ✓ Can be used in cut flower arrangements
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Common Myrtle

Repotting Every 2-3 years, or when the plant becomes root-bound.
Pruning Prune regularly to maintain shape and encourage bushier growth. Best done in late winter or early spring.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season (spring/summer).
Seasonal Care In winter, reduce watering and provide bright light. Protect from frost outdoors. In summer, ensure adequate watering and protect from intense afternoon sun.

Lobelia Cardinalis

Repotting Not applicable as it's primarily an outdoor plant. If grown in containers, repot every 2-3 years in spring.
Pruning Deadhead spent flowers to encourage continued blooming. Cut back to the base in late fall after the foliage has died back.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, applied monthly during the growing season (spring and summer)
Seasonal Care In spring, divide clumps to propagate. In summer, provide consistent moisture and fertilize regularly. In fall, cut back spent flower spikes. In winter, mulch to protect from frost.

🌞 Light Requirements

Common Myrtle

Full sun to partial shade outdoors. Indoors, requires at least 6 hours of direct sunlight daily.

Low light tolerant: ❌ No

Lobelia Cardinalis

Partial shade to full sun (at least 6 hours of direct sunlight)

Low light tolerant: ❌ No

💧 Watering Needs

Common Myrtle

Water thoroughly when the top inch of soil is dry. Overwatering can lead to root rot, indicated by yellowing leaves and a musty smell. Underwatering results in wilting and dry, crispy leaves. Ensure good drainage.

Lobelia Cardinalis

Keep the soil consistently moist, especially during hot weather. Water deeply when the top inch of soil feels dry. Overwatering can lead to root rot, indicated by yellowing leaves and a musty smell. Underwatering results in wilting and dry, crispy leaves.

🌡️ Temperature & Humidity

Common Myrtle

Temperature: 15-27°C

Humidity: 40-60%

Lobelia Cardinalis

Temperature: 15-25°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Common Myrtle

Common Myrtle

Myrtus communis
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced gardeners looking for a fragrant, ornamental plant to grow outdoors in suitable climates.

✅ Choose This Plant If...

  • You appreciate fragrant foliage and flowers.
  • You live in a Mediterranean climate.
  • You want to create a formal garden or topiary.
  • You are an experienced gardener looking for a rewarding challenge.
  • You want to use the plant for culinary or medicinal purposes.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You cannot provide ample direct sunlight indoors.
  • You are a beginner gardener.
📍 Ideal Location: Outdoors: Sunny garden or patio. Indoors: South-facing window with maximum sunlight.
🎨 Style: Mediterranean, Traditional, Cottage
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Myrtus communis contains essential oils that are toxic to dogs, cats, and horses. Symptoms include gastrointestinal upset (vomiting, diarrhea), and dermatitis.
Lobelia Cardinalis

Lobelia Cardinalis

Lobelia cardinalis
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners looking to attract hummingbirds and butterflies to their moist, partially shaded gardens.

✅ Choose This Plant If...

  • You want to attract hummingbirds to your garden.
  • You have a moist, partially shaded area in your yard.
  • You appreciate vibrant red flowers.
  • You enjoy native North American plants.
  • You want a plant that adds vertical interest to your garden.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You have a dry garden.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoor garden or naturalized area with moist soil and partial shade.
🎨 Style: Cottage, Naturalistic, Woodland
🏠 Apartment Friendly: No
⚠️ All parts of the plant are toxic to dogs, cats, and horses. Symptoms include nausea, vomiting, diarrhea, and in severe cases, respiratory paralysis. The toxic compounds are alkaloids.

🎯 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

Common Myrtle Care Tips

Common Myrtle is primarily an outdoor plant and requires specific conditions to thrive indoors, including ample direct sunlight, well-draining soil, and moderate humidity. It is prone to pests and diseases and requires regular monitoring. Maintaining its health indoors can be challenging.

  • Provide excellent drainage to prevent root rot.
  • Ensure ample direct sunlight, especially when grown indoors.
  • Prune regularly to maintain shape and encourage bushier growth.
  • Monitor for pests and diseases and treat promptly.
  • Use rainwater or distilled water to avoid mineral buildup in the soil.
❄️ Winter: Reduce watering frequency. Provide bright, indirect light. Protect from frost if outdoors. Avoid fertilizing during dormancy.
☀️ Summer: Ensure adequate watering, especially during hot weather. Provide some shade during the hottest part of the day to prevent leaf scorch. Fertilize regularly during the growing season.

Lobelia Cardinalis Care Tips

Lobelia cardinalis is primarily an outdoor plant that requires consistent moisture and partial to full sun. Indoor cultivation is challenging due to the need for high light levels and humidity. It is prone to root rot if overwatered and requires regular fertilization during the growing season. It is also toxic to pets.

  • Provide consistent moisture, especially during hot weather.
  • Deadhead spent flowers to encourage more blooms.
  • Divide clumps every few years to prevent overcrowding.
  • Protect from slugs and snails.
  • Mulch around the base of the plant to retain moisture and suppress weeds.
❄️ Winter: Cut back the foliage to the base after it dies back in the fall. Mulch around the base of the plant to protect the roots from frost.
☀️ Summer: Provide consistent moisture, especially during hot weather. Fertilize monthly with a balanced liquid fertilizer. Monitor for pests such as aphids and slugs.

⚠️ Common Problems & Solutions — Plant Care Comparison

Common Myrtle

Common Issues: Scale, spider mites, aphids, root rot
Solutions: Scale, spider mites, aphids: Insecticidal soap or neem oil. Root rot: Improve drainage, reduce watering frequency, and repot in fresh soil.

Lobelia Cardinalis

Common Issues: Root rot, Aphids, Powdery mildew, Slugs and snails
Solutions: Root rot: Improve drainage and reduce watering frequency. Aphids: Spray with insecticidal soap. Powdery mildew: Improve air circulation and apply fungicide. Slugs and snails: Use slug bait or handpick.

❓ Frequently Asked Questions — Comparing These Plants

Common Myrtle

What are the light requirements for Common Myrtle?

Common Myrtle requires bright, indirect light to thrive indoors. A south- or east-facing window is ideal, providing ample sunlight without direct exposure, which can scorch the leaves. If natural light is insufficient, supplement with a grow light. Rotate the plant regularly to ensure even growth on all sides. Signs of insufficient light include leggy growth and pale leaves. Avoid placing the plant in dark corners or areas with minimal light exposure. The goal is to mimic the bright, sunny conditions of its native Mediterranean habitat.

How do I care for Common Myrtle?

Common Myrtle thrives indoors with bright, indirect light. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain a consistent temperature between 60-75°F (15-24°C). Humidity levels should be moderate, around 40-60%. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Prune regularly to maintain shape and encourage bushier growth. Repot every 2-3 years into a slightly larger pot with well-draining potting mix. Protect from drafts and sudden temperature changes. Monitor for pests like spider mites and scale, and treat promptly. Provide consistent care, avoiding extremes in temperature, watering, and light.

How do I propagate Common Myrtle?

Common Myrtle can be propagated through stem cuttings or air layering. For stem cuttings, take 4-6 inch cuttings from new growth in spring or summer. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a well-draining potting mix and keep it moist. Cover with a plastic bag to maintain humidity. Rooting should occur in 4-6 weeks. For air layering, make a small cut on a stem, wrap it with moist sphagnum moss, and cover with plastic wrap. Secure the plastic wrap with tape. Once roots develop, cut the stem below the roots and plant it in a pot. Both methods require patience and consistent moisture.

Lobelia Cardinalis

What are the light requirements for Lobelia Cardinalis?

Lobelia Cardinalis prefers bright, indirect light. While it can tolerate some morning sun, intense afternoon sun can scorch the leaves, especially in hotter climates. When grown indoors, place the plant near an east-facing or west-facing window where it will receive ample light without direct exposure. If you don’t have access to natural light, consider using a grow light to supplement its needs. Insufficient light can lead to leggy growth and reduced flowering. Rotate the plant regularly to ensure even light exposure on all sides. Watch for signs of overexposure, such as bleached or burned leaves, and adjust the plant’s location accordingly.

How do I care for Lobelia Cardinalis?

Lobelia Cardinalis thrives in consistently moist soil, ideally rich in organic matter. Water regularly, especially during dry periods, ensuring the soil doesn’t dry out completely. Provide bright, indirect light; direct sunlight can scorch the leaves. Fertilize every 2-4 weeks during the growing season (spring and summer) with a balanced liquid fertilizer, diluted to half strength. Deadhead spent flowers to encourage continued blooming. Maintain a humid environment, especially if growing indoors; consider using a humidifier or placing the plant on a pebble tray filled with water. Protect from frost in colder climates, either by bringing it indoors or providing adequate winter protection. Repot in spring if the plant becomes root-bound. Monitor for pests such as aphids and spider mites, and treat promptly if necessary. Propagate by seed, division, or stem cuttings.

How do I propagate Lobelia Cardinalis?

Lobelia Cardinalis can be propagated by division, stem cuttings, or seeds. For division, carefully separate the plant into smaller clumps in early spring, ensuring each clump has roots and foliage. Replant the divisions in moist, well-draining soil. For stem cuttings, take 4-6 inch cuttings from healthy stems in spring or summer. Remove the lower leaves and place the cuttings in water or moist potting mix until roots develop. Once rooted, transplant into pots. Seeds can be sown indoors in early spring or directly outdoors after the last frost. Keep the soil consistently moist until germination.

Last updated: April 30, 2026 — Plant care data reviewed and verified by our editorial team.