Larkspur Delphinium vs Pontederia Plant Comparison

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

Larkspur Delphinium

Larkspur Delphinium

Delphinium spp.

VS
Pontederia

Pontederia

Pontederia cordata

Larkspur Delphinium

Larkspur Delphinium

Delphinium spp.

Larkspurs are annual or perennial herbaceous plants known for their tall, elegant flower spikes. They typically grow to heights of 1 to 6 feet, depending on the species and cultivar. The flowers come in a wide range of colors, including blue, purple, pink, white, and yellow. Larkspurs are primarily outdoor plants, prized for their striking vertical presence in gardens and borders. They are grown for their beautiful, showy flowers that attract pollinators.

Ranunculaceae Primarily Northern Hemisphere, including Europe, Asia, and North America
✨ Features: Attracts pollinators like bees and butterflies.
📖 Read Complete Larkspur Delphinium Guide
Pontederia

Pontederia

Pontederia cordata

Pontederia cordata, commonly known as Pickerelweed, is an aquatic perennial plant native to wetlands and shallow water habitats. It features distinctive heart-shaped leaves and striking spikes of blue or purple flowers. Growing up to 1 meter tall, it spreads via rhizomes, forming dense colonies. While primarily an outdoor plant thriving in full sun and wet conditions, it is sometimes grown in water gardens or large aquatic containers. Its attractive flowers and foliage make it a popular choice for naturalizing ponds and providing habitat for wildlife. It is not ideally suited for indoor cultivation due to its high light and moisture requirements.

Pontederiaceae North America, South America
✨ Features: Attracts pollinators, provides habitat for aquatic wildlife, natural water filtration.
📖 Read Complete Pontederia Guide

Quick Plant Comparison

Feature Larkspur Delphinium Pontederia
Light Full sun Full sun to partial shade
Watering Every 3-7 days, depending on weather and soil drainage Daily to maintain consistently wet soil or submerged conditions.
Humidity 30-50% 60-90%
Temperature 15-24°C 15-27°C
Care Level Expert Expert
Growth Rate Moderate Fast, Aggressive Spreader Via Rhizomes
Max Height Rarely grown indoors, outdoor height 0.3-1.8 meters Up to 1 meter (outdoors); significantly smaller if containerized indoors (unlikely to thrive indoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.0) Heavy loam or clay soil, or aquatic planting media
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly (weeding, watering, deadheading) 30 minutes weekly (for outdoor ponds, including algae control and debris removal)

🔬 Botanical Information — Comparing These Plants

Larkspur Delphinium

Scientific Name Delphinium spp.
Family Ranunculaceae
Native To Primarily Northern Hemisphere, including Europe, Asia, and North America
Also Known As Larkspur, Delphinium
Leaves The leaves are deeply lobed and finely divided, giving them a delicate, fern-like appearance. They are typically green or bluish-green in color and arranged alternately along the stem.
Flowers Rarely flowers indoors. Outdoors, they produce tall spikes of spurred flowers in shades of blue, purple, pink, white, and yellow. The flowers bloom in summer.

Pontederia

Scientific Name Pontederia cordata
Family Pontederiaceae
Native To North America, South America
Also Known As Pickerelweed, Pickerel Weed, Heartleaf Pickerelweed
Leaves Heart-shaped (cordate) leaves, typically 10-25 cm long and 5-15 cm wide, with smooth margins and a glossy green color. Leaves are held above the water surface on long petioles.
Flowers Produces erect spikes of small, densely packed blue or purple flowers in summer. Flowering is dependent on sufficient sunlight and warm temperatures. Rarely flowers indoors.

📏 Size & Growth — Plant Comparison

Larkspur Delphinium

Height Rarely grown indoors, outdoor height 0.3-1.8 meters
Spread 0.3-0.6 meters
Growth Rate Moderate
Growth Pattern Upright, with tall flower spikes emerging from a basal rosette of foliage.

Pontederia

Height Up to 1 meter (outdoors); significantly smaller if containerized indoors (unlikely to thrive indoors)
Spread Spreads indefinitely via rhizomes, forming large colonies (outdoors); limited by container size indoors.
Growth Rate Fast, Aggressive Spreader Via Rhizomes
Growth Pattern Upright, emergent aquatic perennial that spreads aggressively via rhizomes, forming dense colonies in shallow water or wet soil.

🌱 Propagation — Comparing Plant Growth

Larkspur Delphinium

Methods: Seed, Division

Difficulty: Moderate

Tips: For seeds, cold stratification is often required. Divide established plants in early spring or fall.

Pontederia

Methods: Division, Seed, Rhizome cuttings

Difficulty: Easy

Tips: Divide rhizomes in spring or early summer. Plant seeds in moist soil. Rhizome cuttings should include a node and be planted in wet soil.

✨ Benefits & Features — Comparing Plant Value

Larkspur Delphinium

Larkspurs are known for their tall, elegant flower spikes and vibrant colors. They are a classic cottage garden flower and a favorite of pollinators. Their toxicity makes them unsuitable for homes with pets or small children.

  • ✓ Attracts pollinators to your garden.
  • ✓ Adds vertical interest and vibrant colors to outdoor spaces.
  • ✓ Provides cut flowers for bouquets.
  • ✓ Can be used to create a classic cottage garden aesthetic.
  • ✓ Offers a sense of accomplishment for experienced gardeners.
  • ⚠️ Toxic to pets

Pontederia

Its distinctive heart-shaped leaves and spikes of blue or purple flowers are visually striking. It's an important plant for wetland ecosystems, providing food and shelter for various wildlife.

  • ✓ Attracts pollinators like bees and butterflies
  • ✓ Provides habitat for aquatic wildlife
  • ✓ Contributes to natural water filtration in ponds
  • ✓ Adds visual interest to water gardens with its unique foliage and flowers
  • ✓ Can help stabilize pond banks and prevent erosion
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Larkspur Delphinium

Repotting Not applicable for indoor growing, but outdoor plants may need division every 3-4 years.
Pruning Deadhead spent flowers to encourage further blooming. Cut back foliage in the fall after flowering.
Fertilizing Balanced fertilizer (10-10-10) applied in spring and early summer at half strength
Seasonal Care In spring, fertilize and provide support for tall varieties. In summer, water regularly and deadhead spent flowers. In fall, cut back foliage after flowering. In winter, provide mulch for protection in colder climates.

Pontederia

Repotting Not typically repotted in aquatic settings. If containerized, divide and replant every 1-2 years to manage rhizome growth.
Pruning Remove dead or yellowing leaves as needed. Cut back foliage in late fall or early spring.
Fertilizing Slow-release aquatic fertilizer in spring, following package instructions.
Seasonal Care In winter, cut back foliage after it dies back. In colder climates, rhizomes may need protection from freezing. In summer, ensure adequate water levels and sunlight.

🌞 Light Requirements

Larkspur Delphinium

Full sun

Low light tolerant: ❌ No

Pontederia

Full sun to partial shade

Low light tolerant: ❌ No

💧 Watering Needs

Larkspur Delphinium

Water deeply when the top inch of soil feels dry. Avoid overhead watering to prevent fungal diseases. Overwatering can lead to root rot, indicated by yellowing leaves and wilting. Underwatering results in dry, crispy leaves and stunted growth.

Pontederia

Requires consistently moist to wet soil. In aquatic settings, the base of the plant should be submerged in water. In containers, keep the soil saturated. Overwatering is not a concern in aquatic environments, but ensure proper drainage in containers to prevent stagnant water. Underwatering will cause wilting and browning of leaves.

🌡️ Temperature & Humidity

Larkspur Delphinium

Temperature: 15-24°C

Humidity: 30-50%

Pontederia

Temperature: 15-27°C

Humidity: 60-90%

🤔 Which Plant Is Right For You?

Larkspur Delphinium

Larkspur Delphinium

Delphinium spp.
Care: Expert Time: 30 minutes weekly (weeding, watering, deadheading) Beginner: No

Experienced gardeners looking to add vertical interest and vibrant colors to their outdoor flower beds.

✅ Choose This Plant If...

  • You want tall, vibrant flowers in your garden.
  • You want to attract pollinators to your yard.
  • You have a sunny garden spot that needs a vertical accent.
  • You enjoy the challenge of growing somewhat finicky plants.
  • You appreciate classic cottage garden flowers.

❌ Skip This Plant If...

  • You have pets or small children who might ingest the plant.
  • You lack a sunny outdoor garden space.
  • You are a beginner gardener looking for easy-to-grow plants.
📍 Ideal Location: Outdoor flower beds or borders with full sun exposure
🎨 Style: Cottage, Traditional, English Garden
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the seeds, are toxic to dogs, cats, and horses. Symptoms include gastrointestinal upset, weakness, and potentially neurological issues. Contains toxic alkaloids.
Pontederia

Pontederia

Pontederia cordata
Care: Expert Time: 30 minutes weekly (for outdoor ponds, including algae control and debris removal) Beginner: No

Gardeners with ponds, water gardens, or large aquatic containers looking to naturalize their landscape and provide habitat for wildlife.

✅ Choose This Plant If...

  • You have a pond or water garden.
  • You want to attract pollinators and wildlife to your yard.
  • You need a plant for natural water filtration.
  • You are experienced with aquatic plant care.
  • You want a visually striking plant with unique flowers and foliage.

❌ Skip This Plant If...

  • You do not have an outdoor aquatic environment.
  • You are looking for a low-maintenance indoor plant.
  • You have pets that may ingest the plant.
📍 Ideal Location: Outdoor pond, water garden, or large aquatic container in a sunny location.
🎨 Style: Naturalistic, Cottagecore, Wild Garden
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Pontederia species contain calcium oxalate crystals, which are toxic to dogs, cats, and horses. Symptoms include oral irritation, excessive drooling, vomiting, and difficulty swallowing.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

☀️

Larkspur Delphinium needs full sun, while Pontederia prefers full sun to partial shade.

📈

Larkspur Delphinium has moderate growth, while Pontederia grows fast, aggressive spreader via rhizomes.

💡 Pro Tips For Comparing These Plants

Larkspur Delphinium Care Tips

Larkspurs are challenging to grow indoors due to their high light requirements and need for cool temperatures. They are best suited for outdoor gardens. Indoor attempts often result in weak, leggy growth and failure to flower. Proper drainage is crucial.

  • Provide support for tall varieties to prevent them from falling over.
  • Ensure well-draining soil to prevent root rot.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Protect from strong winds that can damage the flower spikes.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Cut back foliage after flowering. Provide mulch for protection in colder climates.
☀️ Summer: Water regularly and deadhead spent flowers. Provide support for tall varieties.

Pontederia Care Tips

Pickerelweed is primarily an outdoor aquatic plant. Indoor cultivation is extremely challenging due to its high light, humidity, and water requirements. It requires specialized aquatic setups and is prone to pest infestations and nutrient deficiencies indoors. Not recommended for typical indoor environments.

  • Provide ample sunlight for optimal flowering.
  • Regularly remove dead or decaying leaves to prevent water quality issues.
  • Use aquatic-specific fertilizers to avoid harming aquatic life.
  • Control algae growth to ensure healthy plant growth.
  • Protect rhizomes from freezing temperatures in colder climates.
❄️ Winter: Cut back dead foliage. In colder climates, protect rhizomes from freezing by moving containers to a sheltered location or insulating them.
☀️ Summer: Ensure adequate water levels and sunlight. Monitor for pests and diseases. Fertilize as needed to support flowering.

⚠️ Common Problems & Solutions — Plant Care Comparison

Larkspur Delphinium

Common Issues: Powdery mildew, Crown rot, Aphids, Spider mites
Solutions: Powdery mildew: Improve air circulation and apply fungicide. Crown rot: Ensure well-draining soil and avoid overwatering. Aphids: Insecticidal soap. Spider mites: Increase humidity and use miticide.

Pontederia

Common Issues: Algae growth, Aphids, Nutrient deficiencies, Root rot (if drainage is poor in containers)
Solutions: Control algae with algaecides or by improving water circulation. Treat aphids with insecticidal soap. Address nutrient deficiencies with appropriate aquatic fertilizers. Ensure proper drainage to prevent root rot.

❓ Frequently Asked Questions — Comparing These Plants

Larkspur Delphinium

What are the light requirements for Larkspur Delphinium?

Larkspur Delphiniums thrive in full sun, needing a minimum of six hours of direct sunlight each day to produce abundant blooms. Insufficient light can lead to leggy growth, weak stems, and reduced flowering. When planting, choose a location that receives morning sun, which helps to dry the foliage and prevent fungal diseases.

How do I care for Larkspur Delphinium?

Larkspur Delphiniums need well-draining soil enriched with organic matter. Plant in a location with full sun, providing at least six hours of direct sunlight daily. Water deeply when the top inch of soil feels dry, but avoid overwatering. Fertilize regularly during the growing season with a balanced fertilizer, switching to a fertilizer higher in phosphorus to promote blooming.

How do I propagate Larkspur Delphinium?

Larkspur Delphiniums can be propagated by division, stem cuttings, or seed. Division is best done in spring or fall by carefully separating the root ball and replanting the divisions. For stem cuttings, take 4-6 inch cuttings from new growth in spring, remove the lower leaves, and plant in a well-draining rooting medium. Keep the cuttings moist and in a humid environment until rooted.

Pontederia

What are the light requirements for Pontederia?

Pontederia requires ample sunlight to flourish. Aim for at least 6 hours of direct sunlight daily to encourage abundant flowering. While it can tolerate partial shade, reduced sunlight may result in fewer blooms and leggier growth. For container-grown plants, position them in a sunny location near a window or outdoors in a spot that receives plenty of light. In ponds or water gardens, ensure that Pontederia is not shaded by taller plants or structures. Insufficient light can lead to weak stems and reduced overall health.

How do I care for Pontederia?

Pontederia thrives in full sun to partial shade, requiring at least 6 hours of direct sunlight daily for optimal flowering. It prefers consistently moist conditions, ideally with its roots submerged in water or very wet soil. Maintain water quality by regularly removing debris and algae. Fertilize with a slow-release aquatic plant fertilizer during the growing season (spring and summer) to promote robust growth and abundant blooms. Prune spent flower spikes to encourage further flowering. Monitor for pests such as aphids or snails and treat as needed. In colder climates, protect the roots from freezing by moving the plant to a sheltered location or deeper water. Regularly check and adjust water levels to ensure consistent moisture.

How do I propagate Pontederia?

Pontederia can be easily propagated through division or cuttings.

Last updated: April 19, 2026 — Plant care data reviewed and verified by our editorial team.