Larkspur Delphinium vs Speedwell 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
Speedwell

Speedwell

Veronica spp.

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
Speedwell

Speedwell

Veronica spp.

Speedwell encompasses a diverse genus of flowering plants, primarily herbaceous perennials, though some are annuals or shrubs. They exhibit a range of growth habits, from creeping groundcovers to upright forms. The flowers are typically small and blue, but can also be pink, white, or purple, arranged in spikes or racemes. Speedwell is primarily grown outdoors in gardens and meadows for its attractive flowers and ability to attract pollinators. While some species are relatively adaptable, they generally require specific outdoor conditions that are difficult to replicate indoors.

Plantaginaceae Europe, Asia, North Africa, North America
✨ Features: Attracts pollinators (bees, butterflies), deer-resistant (in some cases), long blooming period.
📖 Read Complete Speedwell Guide

Quick Plant Comparison

Feature Larkspur Delphinium Speedwell
Light Full sun Full sun to partial shade
Watering Every 3-7 days, depending on weather and soil drainage Every 3-7 days, depending on weather and soil drainage
Humidity 30-50% 40-60%
Temperature 15-24°C 15-24°C
Care Level Expert Expert
Growth Rate Moderate Moderate To Fast, Some Species Can Be Aggressive Spreaders
Max Height Rarely grown indoors, outdoor height 0.3-1.8 meters 10-90 cm (outdoor)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.0) Well-draining, loamy soil
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly (weeding, watering, deadheading) 15 minutes weekly (outdoor)

🔬 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.

Speedwell

Scientific Name Veronica spp.
Family Plantaginaceae
Native To Europe, Asia, North Africa, North America
Also Known As Speedwell, Gypsyweed, Bird's Eye
Leaves Leaves are typically small, oval or lance-shaped, and arranged oppositely or alternately along the stem. The color is usually green, but some varieties have variegated foliage.
Flowers Speedwell flowers outdoors in spring and summer. The flowers are small and typically blue, but can also be pink, white, or purple. They are arranged in spikes or racemes.

📏 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.

Speedwell

Height 10-90 cm (outdoor)
Spread 15-60 cm (outdoor), spreads via rhizomes in some species
Growth Rate Moderate To Fast, Some Species Can Be Aggressive Spreaders
Growth Pattern Varies depending on the species. Some are creeping groundcovers, while others are upright and bushy. Some species spread via rhizomes, forming dense mats.

🌱 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.

Speedwell

Methods: Stem cuttings, Division, Seed

Difficulty: Easy To Moderate

Tips: For stem cuttings, take cuttings in spring or summer and root them in water or moist soil. Division is best done in spring or fall. Sow seeds in spring after the last frost.

✨ 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

Speedwell

Speedwell is known for its long blooming period and ability to attract pollinators. The flowers come in a variety of colors, and the plant is relatively low-maintenance. Some species spread aggressively, making them useful as groundcovers.

  • ✓ Attracts pollinators
  • ✓ Provides long-lasting color in the garden
  • ✓ Deer-resistant
  • ✓ Relatively low-maintenance
  • ✓ Can be used as a groundcover
  • ⚠️ 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.

Speedwell

Repotting Not applicable for indoor growing, but if grown in containers outdoors, repot every 2-3 years or as needed.
Pruning Deadhead spent flowers to encourage continued blooming. Prune back in late fall or early spring to maintain shape and size.
Fertilizing Balanced fertilizer (10-10-10) diluted to half strength, applied in spring and early summer
Seasonal Care In spring, fertilize and prune back dead growth. In summer, water regularly and deadhead spent flowers. In fall, divide plants if needed. In winter, provide mulch for protection in colder climates.

🌞 Light Requirements

Larkspur Delphinium

Full sun

Low light tolerant: ❌ No

Speedwell

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.

Speedwell

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Speedwell prefers consistently moist, but not soggy, soil. In hotter weather, more frequent watering may be necessary. Reduce watering during dormancy.

🌡️ Temperature & Humidity

Larkspur Delphinium

Temperature: 15-24°C

Humidity: 30-50%

Speedwell

Temperature: 15-24°C

Humidity: 40-60%

🤔 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.
Speedwell

Speedwell

Veronica spp.
Care: Expert Time: 15 minutes weekly (outdoor) Beginner: No

Outdoor gardeners looking for a low-maintenance, flowering groundcover or border plant that attracts pollinators.

✅ Choose This Plant If...

  • You want a low-maintenance perennial for your garden.
  • You want to attract pollinators to your yard.
  • You need a deer-resistant plant.
  • You want a long-blooming flower.
  • You want a plant with a variety of colors and growth habits.

❌ Skip This Plant If...

  • You are looking for an indoor plant.
  • You have pets that might ingest it.
  • You have limited sunlight in your garden.
📍 Ideal Location: Outdoor garden bed or border with full sun exposure.
🎨 Style: Cottage, Naturalistic, Meadow
🏠 Apartment Friendly: No
⚠️ Some species of Veronica contain glycosides that can cause mild gastrointestinal upset in dogs, cats, and horses if ingested. Symptoms may include vomiting, diarrhea, and loss of appetite. 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

☀️

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

📈

Larkspur Delphinium has moderate growth, while Speedwell grows moderate to fast, some species can be aggressive spreaders.

💡 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.

Speedwell Care Tips

Speedwell is primarily an outdoor plant and is challenging to grow indoors due to its high light requirements and need for specific temperature and humidity conditions. It requires full sun and well-draining soil. Indoor cultivation is not recommended.

  • Provide well-draining soil to prevent root rot.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Fertilize in spring with a balanced fertilizer.
  • Divide plants every few years to prevent overcrowding.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: In colder climates, provide mulch around the base of the plant to protect the roots from freezing. Reduce watering during dormancy. Prune back dead growth in late fall or early spring.
☀️ Summer: Water regularly during hot weather. Deadhead spent flowers to encourage continued blooming. Monitor for pests and diseases.

⚠️ 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.

Speedwell

Common Issues: Powdery mildew, Root rot, Aphids
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Root rot: Ensure well-draining soil and avoid overwatering. Aphids: Spray with insecticidal soap.

❓ 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.

Speedwell

What are the light requirements for Speedwell?

Speedwell flourishes in full sun, requiring at least six hours of direct sunlight each day for optimal growth and abundant blooming. While it can tolerate some partial shade, especially in hotter climates, insufficient light can lead to leggy growth and reduced flowering. When planting Speedwell, choose a location that receives ample sunlight throughout the day. If growing indoors, place the plant near a sunny window, ideally facing south or east. Rotate the plant regularly to ensure even light exposure on all sides. In areas with intense afternoon sun, providing some light shade during the hottest part of the day can prevent leaf scorch.

How do I care for Speedwell?

Speedwell thrives in well-draining soil and requires regular watering, especially during dry periods. Aim to keep the soil consistently moist, but avoid overwatering, which can lead to root rot. Provide Speedwell with at least six hours of sunlight daily for optimal blooming. In hotter climates, some afternoon shade can be beneficial. Fertilize your Speedwell every 4-6 weeks during the growing season with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers regularly to encourage continuous flowering. Prune back the plant in late fall or early spring to maintain its shape and promote bushier growth. Protect Speedwell from extreme cold and frost in colder climates. Monitor for pests and diseases, and treat promptly if necessary.

How do I propagate Speedwell?

Speedwell can be propagated through division, stem cuttings, and seeds.

Last updated: May 3, 2026 — Plant care data reviewed and verified by our editorial team.