Lobelia Cardinalis vs Nasturtium 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
Nasturtium

Nasturtium

Tropaeolum majus

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
Nasturtium

Nasturtium

Tropaeolum majus

Nasturtium (Tropaeolum majus) is an annual flowering plant known for its vibrant, edible flowers and peppery-flavored leaves. It features round, shield-shaped leaves and spurred flowers in shades of orange, yellow, and red. Typically grown outdoors in gardens and containers, it's valued for its ornamental appeal, culinary uses, and ability to attract pollinators. It's not ideally suited as a long-term indoor plant due to its high light requirements and sprawling growth habit.

Tropaeolaceae Andes Mountains of South America (Peru, Bolivia)
✨ Features: Edible flowers and leaves, attracts pollinators, natural pest repellent.
📖 Read Complete Nasturtium Guide

Quick Plant Comparison

Feature Lobelia Cardinalis Nasturtium
Light Partial shade to full sun (at least 6 hours of direct sunlight) Full sun to partial shade. Requires at least 6 hours of direct sunlight for optimal flowering.
Watering Every 2-3 days, depending on weather and soil drainage Every 2-3 days in hot weather, every 5-7 days in cooler weather, adjust based on soil moisture.
Humidity 40-60% 40-60%
Temperature 15-25°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Fast
Max Height 0.6-1.2 meters (2-4 feet) 30-60 cm (outdoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Rich, well-drained soil with plenty of organic matter Well-draining, moderately fertile soil. Avoid overly rich soil, as it can promote foliage growth at the expense of flowers.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 10-15 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.

Nasturtium

Scientific Name Tropaeolum majus
Family Tropaeolaceae
Native To Andes Mountains of South America (Peru, Bolivia)
Also Known As Nasturtium, Garden Nasturtium, Indian Cress, Monk's Cress
Leaves The leaves are round, shield-shaped, and have a slightly waxy texture. They are typically green but can also have a bluish tint. The leaves are attached to the stem in the center, giving them a unique appearance.
Flowers Nasturtiums produce spurred flowers in shades of orange, yellow, and red. The flowers are edible and have a peppery flavor. They bloom profusely throughout the summer and fall.

📏 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.

Nasturtium

Height 30-60 cm (outdoors)
Spread 30-90 cm (outdoors)
Growth Rate Fast
Growth Pattern Nasturtiums have a sprawling growth habit, with trailing stems that can reach up to 3 feet long. They can be grown as a ground cover or allowed to cascade over the edges of containers.

🌱 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.

Nasturtium

Methods: Seed

Difficulty: Easy

Tips: Sow seeds directly into the garden after the last frost or start indoors 4-6 weeks before the last frost. Soak seeds overnight to improve germination.

✨ 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

Nasturtium

Nasturtiums are unique for their edible flowers and leaves, which have a distinctive peppery flavor. They also act as a natural pest repellent, making them a valuable addition to vegetable gardens. Their vibrant colors and ease of growth from seed make them a popular choice for gardeners.

  • ✓ Edible flowers and leaves provide a peppery flavor to salads and other dishes.
  • ✓ Attracts pollinators like bees and butterflies to the garden.
  • ✓ Acts as a natural pest repellent, protecting other plants.
  • ✓ Adds vibrant color and visual interest to the garden.
  • ✓ Relatively easy to grow from seed outdoors.
  • ⚠️ 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.

Nasturtium

Repotting Not typically repotted as they are annuals. If grown in containers, choose a large enough container initially.
Pruning Pinch back stems to encourage bushier growth and more flowers. Remove spent flowers to prolong blooming.
Fertilizing Balanced liquid fertilizer diluted to half strength, every 4-6 weeks during the growing season. Avoid high-nitrogen fertilizers.
Seasonal Care In spring and summer, provide regular watering and fertilization. In fall, reduce watering as temperatures cool. Nasturtiums are annuals and will die back in winter.

🌞 Light Requirements

Lobelia Cardinalis

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

Low light tolerant: ❌ No

Nasturtium

Full sun to partial shade. Requires at least 6 hours of direct sunlight for optimal flowering.

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.

Nasturtium

Water regularly, allowing the soil to dry slightly between waterings. Overwatering can lead to root rot, while underwatering can cause wilting and reduced flowering. Check soil moisture before watering.

🌡️ Temperature & Humidity

Lobelia Cardinalis

Temperature: 15-25°C

Humidity: 40-60%

Nasturtium

Temperature: 15-25°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.
Nasturtium

Nasturtium

Tropaeolum majus
Care: Expert Time: 10-15 minutes weekly Beginner: No

Gardeners looking for edible flowers and foliage to add to salads and other dishes.

✅ Choose This Plant If...

  • You want edible flowers and leaves for culinary use.
  • You want to attract pollinators to your garden.
  • You need a natural pest repellent for your vegetable garden.
  • You enjoy vibrant, colorful flowers.
  • You have a sunny outdoor space.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You don't have a sunny outdoor space.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Sunny garden bed or outdoor container.
🎨 Style: Cottage, Bohemian, Eclectic
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Nasturtium contains compounds that can cause mild gastrointestinal upset in dogs, cats, and horses. Symptoms include vomiting, diarrhea, and drooling. All parts of the plant are potentially 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

📈

Lobelia Cardinalis has moderate growth, while Nasturtium grows fast.

💡 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.

Nasturtium Care Tips

Nasturtiums are best grown outdoors due to their need for full sun. Indoor cultivation is challenging and requires very bright light and careful watering. They are prone to pests and diseases, and their sprawling growth habit can be difficult to manage in a container.

  • Soak seeds overnight before planting to improve germination.
  • Avoid over-fertilizing, as it can lead to excessive foliage growth and fewer flowers.
  • Pinch back stems regularly to encourage bushier growth.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Monitor for pests like aphids and whiteflies and treat promptly.
❄️ Winter: Nasturtiums are annuals and will die back in winter. Remove dead foliage and discard the plants.
☀️ Summer: Provide regular watering and fertilization during the summer growing season. Monitor for pests and diseases and treat promptly. Pinch back stems to encourage bushier growth and more flowers.

⚠️ 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.

Nasturtium

Common Issues: Aphids, whiteflies, root rot, fungal diseases
Solutions: Insecticidal soap for aphids and whiteflies, improve drainage to prevent root rot, fungicide for fungal diseases.

❓ 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.

Nasturtium

What are the light requirements for Nasturtium?

Nasturtiums thrive best in full sun, requiring at least 6 hours of direct sunlight each day for abundant flowering. While they can tolerate partial shade, reduced sunlight can lead to fewer blooms and leggy growth. In hotter climates, providing some afternoon shade can prevent leaf scorch.

How do I care for Nasturtium?

Nasturtiums are relatively easy to care for, making them a great choice for beginner gardeners. They thrive in full sun to partial shade, requiring at least 6 hours of sunlight per day for optimal blooming. Water regularly, allowing the soil to dry slightly between waterings; avoid overwatering, which can lead to root rot.

How do I propagate Nasturtium?

Nasturtiums are easily propagated from seeds or stem cuttings. To propagate from seeds, sow seeds directly into the garden or containers in spring after the last frost. Alternatively, start seeds indoors 4-6 weeks before the last frost. Soak seeds in water overnight to improve germination.

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