Larkspur Delphinium vs Pickerel Weed Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
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.
Pickerel Weed
Pontederia cordata
Pickerelweed is an aquatic perennial herb typically found in shallow water habitats like ponds, marshes, and streams. It features distinctive heart-shaped leaves and a prominent flower spike that blooms in summer. The plant grows from rhizomes, forming dense colonies. While primarily an outdoor plant, it is occasionally grown in large water gardens or aquariums. It is valued for its attractive foliage and flowers, which attract pollinators and provide habitat for aquatic wildlife.
Quick Plant Comparison
| Feature | Larkspur Delphinium | Pickerel Weed |
|---|---|---|
| Light | Full sun | Full sun to partial shade |
| Watering | Every 3-7 days, depending on weather and soil drainage | Daily to maintain water levels |
| Humidity | 30-50% | 60-90% |
| Temperature | 15-24°C | 15-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Fast |
| Max Height | Rarely grown indoors, outdoor height 0.3-1.8 meters | 0.3-1 meter (outdoor, less in containers) |
| 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 clay soil or aquatic planting mix |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly (weeding, watering, deadheading) | 30 minutes weekly (including algae control, pruning, and water level maintenance) |
🔬 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. |
Pickerel Weed
| 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. The leaves are smooth, glossy green, and have prominent veins. They are attached to long petioles that emerge from the rhizomes. |
| Flowers | Produces a dense spike of small, violet-blue flowers in summer. The flowers are about 1 cm long and have six petals. They are arranged spirally around the spike and bloom sequentially from the bottom up. Rarely flowers indoors. |
📏 Size & Growth — Plant Comparison
Larkspur Delphinium
Pickerel Weed
🌱 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.
Pickerel Weed
Methods: Division of rhizomes, Seed
Difficulty: Easy
Tips: Divide rhizomes in spring or early summer. Ensure each division has healthy roots and shoots. Plant in aquatic soil and keep submerged in water. Seeds can be sown in shallow water in spring.
✨ 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
Pickerel Weed
Pickerelweed is a native aquatic plant that provides important habitat and food sources for wildlife. Its distinctive heart-shaped leaves and purple flower spikes make it an attractive addition to water gardens. It is also known for its ability to help filter and oxygenate water.
- ✓ Provides habitat for aquatic wildlife
- ✓ Attracts pollinators such as bees and butterflies
- ✓ Helps to filter and oxygenate water in ponds and aquariums
- ✓ Adds visual interest with its unique foliage and flowers
- ✓ Contributes to a natural and balanced ecosystem in aquatic environments
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Larkspur Delphinium
Pickerel Weed
🌞 Light Requirements
Larkspur Delphinium
Full sun
Low light tolerant: ❌ No
Pickerel Weed
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.
Pickerel Weed
Requires consistently moist to wet conditions. If grown in a container, ensure the pot is sitting in a tray of water or submerged in a larger water feature. Overwatering is not a concern as it is an aquatic plant. Underwatering will cause the leaves to wilt and brown.
🌡️ Temperature & Humidity
Larkspur Delphinium
Temperature: 15-24°C
Humidity: 30-50%
Pickerel Weed
Temperature: 15-27°C
Humidity: 60-90%
🤔 Which Plant Is Right For You?
Larkspur Delphinium
Delphinium spp.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.
Pickerel Weed
Pontederia cordataExperienced gardeners with ponds, water gardens, or large aquariums who want to add a native aquatic plant.
✅ Choose This Plant If...
- You have a pond or water garden and want a native plant.
- You want to attract pollinators and wildlife to your water feature.
- You need a plant that can tolerate consistently wet conditions.
- You appreciate the unique heart-shaped foliage and flower spikes.
- You are an experienced gardener looking for a rewarding aquatic plant challenge.
❌ Skip This Plant If...
- You do not have a suitable aquatic environment (pond, water garden, large aquarium).
- You are looking for a low-maintenance indoor plant.
- You have pets that might ingest the plant, as it is toxic to them.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Larkspur Delphinium needs full sun, while Pickerel Weed prefers full sun to partial shade.
Larkspur Delphinium has moderate growth, while Pickerel Weed grows fast.
💡 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.
Pickerel Weed Care Tips
Pickerelweed is best suited for outdoor water gardens or large aquariums. It requires full sun and consistently wet conditions. Indoor cultivation is challenging due to the need for specialized aquatic environments and intense lighting. It is an aggressive spreader and needs containment.
- Ensure consistent water levels, especially during hot weather.
- Provide full sun for optimal flowering.
- Use aquatic plant fertilizer to promote healthy growth.
- Control algae growth to prevent it from smothering the plant.
- Protect rhizomes from freezing in colder climates.
⚠️ Common Problems & Solutions — Plant Care Comparison
Larkspur Delphinium
Pickerel Weed
❓ 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.
Pickerel Weed
What are the light requirements for Pickerel Weed?
Pickerel Weed thrives best in full sun, requiring at least six hours of direct sunlight daily. However, it can also tolerate partial shade, especially during the hottest part of the day. Insufficient light can lead to leggy growth, reduced flowering, and overall weaker plants.
How do I care for Pickerel Weed?
Pickerel Weed thrives in shallow water or moist soil. Plant in a pond, water garden, or a container submerged in water. Full sun to partial shade is ideal. Ensure the water is clean and well-oxygenated. Add aquatic plant fertilizer sparingly during the growing season (spring and summer). Remove dead leaves and flowers regularly.
How do I propagate Pickerel Weed?
Pickerel Weed can be easily propagated through division or cuttings.
Last updated: May 1, 2026 — Plant care data reviewed and verified by our editorial team.