Iceland Poppy vs Lobelia Cardinalis Plant Comparison

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

Iceland Poppy

Iceland Poppy

Papaver nudicaule

VS
Lobelia Cardinalis

Lobelia Cardinalis

Lobelia cardinalis

Iceland Poppy

Iceland Poppy

Papaver nudicaule

The Iceland Poppy is a short-lived perennial or biennial often grown as an annual, prized for its delicate, crepe-paper-like flowers in a range of colors including yellow, orange, red, pink, and white. It typically reaches a height of 30-60 cm. While primarily an outdoor plant, it is grown for its vibrant blooms in garden beds, borders, and containers. Its cup-shaped flowers are borne on slender, hairy stems above a rosette of bluish-green, deeply lobed leaves. It is not naturally an indoor plant and struggles to thrive indoors due to high light requirements and specific temperature needs.

Papaveraceae Subpolar regions of Europe, Asia, and North America, including Iceland
✨ Features: Attracts pollinators, deer-resistant, cut flowers
📖 Read Complete Iceland Poppy 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 Iceland Poppy Lobelia Cardinalis
Light Full sun (at least 6 hours of direct sunlight daily) Partial shade to full sun (at least 6 hours of direct sunlight)
Watering Every 7-10 days, depending on weather and soil drainage Every 2-3 days, depending on weather and soil drainage
Humidity 30-50% 40-60%
Temperature 10-21°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height 30-60 cm outdoors; significantly smaller and weaker indoors (if grown) 0.6-1.2 meters (2-4 feet)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, moderately fertile soil. A mix of garden soil, sand, and compost is suitable. Rich, well-drained soil with plenty of organic matter
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly during the growing season 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Iceland Poppy

Scientific Name Papaver nudicaule
Family Papaveraceae
Native To Subpolar regions of Europe, Asia, and North America, including Iceland
Also Known As Iceland Poppy, Arctic Poppy
Leaves The leaves are bluish-green, deeply lobed, and form a basal rosette. They are typically 10-20 cm long and have a slightly hairy texture.
Flowers It rarely flowers indoors. Outdoors, it produces cup-shaped flowers in a variety of colors, including yellow, orange, red, pink, and white. The flowers are typically 5-7 cm in diameter and have a delicate, crepe-paper-like texture.

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

Iceland Poppy

Height 30-60 cm outdoors; significantly smaller and weaker indoors (if grown)
Spread 20-30 cm
Growth Rate Moderate
Growth Pattern It grows as a rosette of basal leaves from which slender, hairy flower stalks emerge, each bearing a single, cup-shaped flower. It has an upright growth habit.

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

Iceland Poppy

Methods: Seed

Difficulty: Easy

Tips: Sow seeds directly in the garden in early spring or late fall. Seeds require light to germinate, so do not cover them with too much soil. Keep the soil consistently moist until germination.

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

Iceland Poppy

The crepe-paper-like texture of the petals and the wide range of vibrant colors make Iceland Poppies unique. They are also relatively deer-resistant, making them a good choice for gardens where deer are a problem. They are also known for their delicate, papery blooms and ability to thrive in cooler climates.

  • ✓ Adds vibrant color to the garden
  • ✓ Attracts pollinators like bees and butterflies
  • ✓ Provides cut flowers for arrangements
  • ✓ Deer resistant, protecting other plants
  • ✓ Relatively easy to grow from seed outdoors
  • ⚠️ 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

Iceland Poppy

Repotting Not applicable, as it's typically grown as an annual or short-lived perennial outdoors.
Pruning Deadhead spent flowers to encourage more blooms. Cut back foliage in late fall.
Fertilizing Balanced slow-release fertilizer in spring, diluted liquid fertilizer every 4-6 weeks during the growing season.
Seasonal Care In spring, sow seeds or transplant seedlings. Provide regular watering and fertilization during the growing season. In fall, allow plants to self-seed or collect seeds for next year. In winter, plants may die back in colder climates.

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

Iceland Poppy

Full sun (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

Iceland Poppy

Water thoroughly when the top inch of soil feels dry to the touch. Avoid overwatering, as it can lead to root rot. Ensure good drainage. Overwatering signs include yellowing leaves and wilting, while underwatering presents as drooping leaves and dry, crispy edges.

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

Iceland Poppy

Temperature: 10-21°C

Humidity: 30-50%

Lobelia Cardinalis

Temperature: 15-25°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Iceland Poppy

Iceland Poppy

Papaver nudicaule
Care: Expert Time: 15 minutes weekly during the growing season Beginner: No

Gardeners in cooler climates seeking vibrant, early-season color in their flower beds.

✅ Choose This Plant If...

  • You want vibrant, early-season color in your garden.
  • You live in a cooler climate where they thrive.
  • You want to attract pollinators to your garden.
  • You enjoy cut flowers with a long vase life.
  • You want a deer-resistant plant.

❌ Skip This Plant If...

  • You live in a hot, humid climate.
  • You are looking for a long-lived perennial.
  • You have pets that might ingest the plant.
📍 Ideal Location: Outdoor garden bed or container in full sun
🎨 Style: Cottage, Romantic, Traditional
🏠 Apartment Friendly: No
⚠️ All parts of the plant contain alkaloids that can be toxic to dogs, cats, and horses. Symptoms include gastrointestinal upset (vomiting, diarrhea), depression, and incoordination. Contact a veterinarian immediately if ingestion is suspected.
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

☀️

Iceland Poppy needs full sun (at least 6 hours of direct sunlight daily), while Lobelia Cardinalis prefers partial shade to full sun (at least 6 hours of direct sunlight).

💡 Pro Tips For Comparing These Plants

Iceland Poppy Care Tips

Iceland Poppies are best grown outdoors. Indoor cultivation is extremely challenging due to their high light requirements and need for cool temperatures. They are prone to fungal diseases if kept too humid. Success indoors is unlikely without supplemental lighting and careful environmental control.

  • Sow seeds directly in the garden in early spring or late fall for best results.
  • Ensure well-draining soil to prevent root rot.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Provide full sun for optimal flowering.
  • Protect from strong winds, which can damage the delicate stems.
❄️ Winter: In colder climates, the plant may die back in winter. Provide a layer of mulch to protect the roots. In milder climates, the plant may remain evergreen.
☀️ Summer: Provide regular watering during dry periods. Deadhead spent flowers to encourage more blooms. Protect from intense afternoon sun in hotter climates.

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

Iceland Poppy

Common Issues: Root rot, powdery mildew, aphids, lack of flowering
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap. Lack of flowering: Provide adequate sunlight and fertilizer.

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

Iceland Poppy

What are the light requirements for Iceland Poppy?

Iceland Poppies require at least six hours of direct sunlight per day to thrive and produce abundant blooms. Ideally, provide them with morning sun and some afternoon shade, especially in hotter climates. Insufficient light can lead to leggy growth, fewer flowers, and duller colors. When growing indoors, place them near a sunny south-facing window. Rotate the plants regularly to ensure even light exposure on all sides. If natural light is insufficient, supplement with grow lights, positioning them about 6-12 inches above the plants. Light intensity is crucial for vibrant blooms.

How do I care for Iceland Poppy?

Iceland Poppies thrive in full sun and well-drained soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize sparingly with a balanced fertilizer, focusing on a formula higher in phosphorus to encourage blooming. Deadhead spent flowers to promote continuous blooming. Provide support for taller varieties to prevent them from flopping over. Protect from strong winds and extreme heat. In warmer climates, provide afternoon shade. Regularly check for pests and diseases. Mulch around the base of the plant to retain moisture and suppress weeds. Ensure good air circulation to prevent fungal diseases. Iceland Poppies are generally short-lived perennials, often grown as annuals.

How do I propagate Iceland Poppy?

Iceland Poppies are primarily propagated by seed. Direct sowing is preferred as they don’t like root disturbance.

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: May 1, 2026 — Plant care data reviewed and verified by our editorial team.