Lobelia Cardinalis vs New Guinea Impatiens Plant Comparison

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

Lobelia Cardinalis

Lobelia Cardinalis

Lobelia cardinalis

VS
New Guinea Impatiens

New Guinea Impatiens

Impatiens hawkeri

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
New Guinea Impatiens

New Guinea Impatiens

Impatiens hawkeri

New Guinea Impatiens are popular flowering plants known for their vibrant, showy blooms and attractive foliage. They are herbaceous perennials, typically grown as annuals in cooler climates. They feature succulent stems and oval to lance-shaped leaves that can be green, bronze, or variegated. The flowers come in a wide range of colors, including red, pink, orange, purple, and white. While primarily outdoor plants, they can be grown indoors with sufficient light. People grow them for their continuous blooms and relatively easy care.

Balsaminaceae New Guinea and the Solomon Islands
✨ Features: Long blooming period, wide range of flower colors.
📖 Read Complete New Guinea Impatiens Guide

Quick Plant Comparison

Feature Lobelia Cardinalis New Guinea Impatiens
Light Partial shade to full sun (at least 6 hours of direct sunlight) Bright, indirect light is essential. Avoid direct sunlight, especially during the hottest part of the day, as it can scorch the leaves. Insufficient light will result in fewer flowers and leggy growth.
Watering Every 2-3 days, depending on weather and soil drainage Every 3-5 days, depending on environmental conditions and pot size.
Humidity 40-60% 40-60%
Temperature 15-25°C 18-24°C
Care Level Expert Moderate
Growth Rate Moderate Moderate
Max Height 0.6-1.2 meters (2-4 feet) 30-60 cm (indoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Rich, well-drained soil with plenty of organic matter Well-draining potting mix, such as a peat-based mix amended with perlite or vermiculite.
Beginner Friendly ❌ No With Caution
Weekly Maintenance 15 minutes weekly 10 minutes weekly

🔬 Botanical Information — Comparing These Plants

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.

New Guinea Impatiens

Scientific Name Impatiens hawkeri
Family Balsaminaceae
Native To New Guinea and the Solomon Islands
Also Known As New Guinea Impatiens, New Guinea Impatient
Leaves Oval to lance-shaped leaves, typically 5-10 cm long. The leaves can be green, bronze, or variegated with shades of yellow, cream, or pink. They have a slightly succulent texture.
Flowers Yes, they can flower indoors with sufficient light. The flowers are single or double and come in a wide range of colors, including red, pink, orange, purple, and white. They are typically 5-7 cm in diameter.

📏 Size & Growth — Plant Comparison

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.

New Guinea Impatiens

Height 30-60 cm (indoors)
Spread 30-45 cm
Growth Rate Moderate
Growth Pattern Bushy, upright growth habit. They tend to fill out their container well and can become somewhat leggy if not pruned regularly.

🌱 Propagation — Comparing Plant Growth

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.

New Guinea Impatiens

Methods: Stem cuttings, Seed

Difficulty: Easy

Tips: Take stem cuttings about 5-7 cm long, remove the lower leaves, and place them in water or moist potting mix. Keep the cuttings in a warm, humid environment until roots develop.

✨ Benefits & Features — Comparing Plant Value

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

New Guinea Impatiens

New Guinea Impatiens are known for their large, showy flowers and attractive foliage, which can be green, bronze, or variegated. They also tend to be more sun-tolerant than common Impatiens.

  • ✓ Adds vibrant color to indoor spaces.
  • ✓ Provides a long blooming period.
  • ✓ Relatively easy to propagate.
  • ✓ Can improve mood and reduce stress.
  • ✓ Offers a variety of flower colors to match decor.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

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.

New Guinea Impatiens

Repotting Repot annually in spring if the plant becomes root-bound.
Pruning Pinch back stems regularly to encourage bushier growth and more blooms. Remove spent flowers to promote continuous blooming.
Fertilizing Use a balanced liquid fertilizer (10-10-10) diluted to half strength every 2-4 weeks during the growing season (spring and summer).
Seasonal Care In spring and summer, provide regular watering and fertilization to encourage blooming. In fall and winter, reduce watering and fertilization as growth slows down. Protect from frost.

🌞 Light Requirements

Lobelia Cardinalis

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

Low light tolerant: ❌ No

New Guinea Impatiens

Bright, indirect light is essential. Avoid direct sunlight, especially during the hottest part of the day, as it can scorch the leaves. Insufficient light will result in fewer flowers and leggy growth.

Low light tolerant: ❌ No

💧 Watering Needs

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.

New Guinea Impatiens

Water thoroughly when the top inch of soil feels dry to the touch. Avoid overwatering, as this can lead to root rot. Allow excess water to drain away. Signs of underwatering include wilting leaves, while overwatering can cause yellowing leaves and stem rot.

🌡️ Temperature & Humidity

Lobelia Cardinalis

Temperature: 15-25°C

Humidity: 40-60%

New Guinea Impatiens

Temperature: 18-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

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.
New Guinea Impatiens

New Guinea Impatiens

Impatiens hawkeri
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Gardeners who want a vibrant, flowering plant for containers or garden beds, and who can provide bright, indirect light indoors.

✅ Choose This Plant If...

  • You want a plant with vibrant, long-lasting blooms.
  • You have a location with bright, indirect light.
  • You enjoy deadheading flowers to encourage more blooms.
  • You want a plant that is relatively easy to propagate from cuttings.
  • You appreciate a wide variety of flower colors to choose from.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You struggle to provide consistent moisture without overwatering.
  • You don't have a location with sufficient bright, indirect light.
📍 Ideal Location: East-facing window, bright bathroom, or under grow lights.
🎨 Style: Tropical, Cottagecore, Bohemian
🏠 Apartment Friendly: Yes
⚠️ According to the ASPCA, New Guinea Impatiens are toxic to dogs, cats, and horses. Symptoms of ingestion can include vomiting, diarrhea, and drooling. All parts of the plant are considered toxic.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly New Guinea Impatiens

⚡ Key Differences Between These Plants

🎯

Lobelia Cardinalis is rated Expert care level, while New Guinea Impatiens is Moderate.

💡 Pro Tips For Comparing These Plants

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.

New Guinea Impatiens Care Tips

New Guinea Impatiens require bright, indirect light and consistent moisture. They are susceptible to root rot if overwatered. While they can be grown indoors, providing adequate light can be challenging. Regular fertilization promotes abundant blooms. Watch for pests like aphids and spider mites.

  • Provide bright, indirect light to encourage blooming.
  • Water thoroughly when the top inch of soil is dry, but avoid overwatering.
  • Fertilize regularly during the growing season with a balanced liquid fertilizer.
  • Pinch back stems to promote bushier growth.
  • Monitor for pests like aphids and spider mites and treat promptly.
❄️ Winter: Reduce watering frequency and stop fertilizing during the winter months. Provide bright, indirect light and maintain a temperature above 15°C. Protect from drafts.
☀️ Summer: Provide consistent moisture and fertilize regularly during the summer months. Protect from direct sunlight, especially during the hottest part of the day. Increase humidity if possible.

⚠️ Common Problems & Solutions — Plant Care Comparison

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.

New Guinea Impatiens

Common Issues: Root rot, Aphids, Spider mites, Leaf drop
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Remove affected roots and repot in fresh soil.|Aphids: Spray with insecticidal soap or neem oil.|Spider mites: Increase humidity and spray with insecticidal soap or miticide.|Leaf drop: Check for underwatering, overwatering, or temperature stress.

❓ Frequently Asked Questions — Comparing These Plants

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.

New Guinea Impatiens

What are the light requirements for New Guinea Impatiens?

New Guinea Impatiens prefer bright, indirect light. They thrive in partial shade, making them ideal for locations that receive morning sun and afternoon shade, or dappled sunlight throughout the day. Direct sunlight can scorch their leaves and fade their flowers, so avoid placing them in areas with intense, prolonged sun exposure.

How do I care for New Guinea Impatiens?

New Guinea Impatiens thrive in partial shade with consistent moisture. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Fertilize regularly during the growing season (spring to fall) with a balanced, water-soluble fertilizer, or one formulated for blooming plants, diluted to half strength, every 2-4 weeks to encourage abundant blooms. Maintain a humid environment by misting the plant regularly or placing it near a humidifier.

How do I propagate New Guinea Impatiens?

New Guinea Impatiens are easily propagated through stem cuttings. Take a 4-6 inch cutting from a healthy stem, removing the lower leaves. Dip the cut end in rooting hormone and plant it in a well-draining potting mix. Keep the soil moist and provide bright, indirect light. Roots should develop within a few weeks. Division is possible when repotting larger plants, carefully separating the root ball. Keiki propagation is not applicable to New Guinea Impatiens.

Last updated: May 15, 2026 — Plant care data reviewed and verified by our editorial team.