Astilbe vs Larkspur Delphinium Plant Comparison

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

Astilbe

Astilbe

Astilbe spp.

VS
Larkspur Delphinium

Larkspur Delphinium

Delphinium spp.

Astilbe

Astilbe

Astilbe spp.

Astilbe is a genus of herbaceous perennial plants known for their feathery plumes of flowers and attractive, fern-like foliage. Typically grown outdoors in shade or partial shade gardens, they add texture and color with their blooms in shades of pink, red, purple, and white. Astilbes are rhizomatous, meaning they spread horizontally underground. They are valued for their ability to thrive in moist, shady conditions where other flowering plants may struggle. They are not typically grown indoors due to their need for specific temperature and humidity conditions.

Saxifragaceae Asia and North America
✨ Features: Attractive foliage, showy flowers, shade tolerance
📖 Read Complete Astilbe Guide
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

Quick Plant Comparison

Feature Astilbe Larkspur Delphinium
Light Partial shade to full shade. Requires protection from intense direct sunlight. Full sun
Watering Every 2-3 days, depending on weather and soil drainage Every 3-7 days, depending on weather and soil drainage
Humidity 40-70% 30-50%
Temperature 16-21°C 15-24°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Not typically grown indoors, but if attempted, expect 30-60 cm Rarely grown indoors, outdoor height 0.3-1.8 meters
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Rich, well-draining soil with plenty of organic matter. A mix of peat moss, compost, and perlite is suitable. Well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.0)
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 30 minutes weekly (weeding, watering, deadheading)

🔬 Botanical Information — Comparing These Plants

Astilbe

Scientific Name Astilbe spp.
Family Saxifragaceae
Native To Asia and North America
Also Known As False Spirea, False Goat's Beard
Leaves The leaves are compound, fern-like, and deeply divided. They are typically dark green, but some varieties have bronze or reddish hues. The texture is delicate and airy.
Flowers Astilbe is rarely, if ever, induced to flower indoors. Outdoors, it produces showy plumes of tiny flowers in shades of pink, red, purple, and white. The flowers bloom in summer and last for several weeks.

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.

📏 Size & Growth — Plant Comparison

Astilbe

Height Not typically grown indoors, but if attempted, expect 30-60 cm
Spread 30-60 cm, spreads via rhizomes
Growth Rate Moderate
Growth Pattern Astilbe grows in clumps, with upright flower stalks emerging from a base of fern-like foliage. It spreads slowly via rhizomes, forming colonies over time.

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.

🌱 Propagation — Comparing Plant Growth

Astilbe

Methods: Division, Seed

Difficulty: Moderate

Tips: Divide rhizomes in early spring or fall. Sow seeds in a cold frame in the fall.

Larkspur Delphinium

Methods: Seed, Division

Difficulty: Moderate

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

✨ Benefits & Features — Comparing Plant Value

Astilbe

Astilbe's feathery flower plumes and fern-like foliage provide a unique texture and visual appeal in shady gardens. Its ability to thrive in moist, shady conditions makes it a valuable addition to areas where other flowering plants may struggle. The variety of flower colors allows for diverse garden designs.

  • ✓ Adds color and texture to shady gardens.
  • ✓ Attracts pollinators like bees and butterflies.
  • ✓ Deer-resistant.
  • ✓ Relatively low-maintenance once established.
  • ✓ Provides long-lasting blooms.
  • ⚠️ Toxic to pets

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

📅 Maintenance Schedule — Plant Care Comparison

Astilbe

Repotting Not applicable for outdoor planting. If grown in containers, divide and repot every 2-3 years to manage rhizome spread.
Pruning Remove spent flower stalks to encourage new blooms. Cut back foliage in late fall or early spring.
Fertilizing Balanced slow-release fertilizer in early spring. Avoid over-fertilizing.
Seasonal Care In spring, apply fertilizer and mulch. In summer, ensure adequate moisture. In fall, cut back foliage after it dies back. In winter, protect rhizomes with mulch in colder climates.

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.

🌞 Light Requirements

Astilbe

Partial shade to full shade. Requires protection from intense direct sunlight.

Low light tolerant: ❌ No

Larkspur Delphinium

Full sun

Low light tolerant: ❌ No

💧 Watering Needs

Astilbe

Keep soil consistently moist, especially during hot weather. Avoid letting the soil dry out completely. Overwatering can lead to root rot, so ensure good drainage. Signs of underwatering include wilting leaves and dry soil. Signs of overwatering include yellowing leaves and soggy soil.

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.

🌡️ Temperature & Humidity

Astilbe

Temperature: 16-21°C

Humidity: 40-70%

Larkspur Delphinium

Temperature: 15-24°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Astilbe

Astilbe

Astilbe spp.
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners with shady, moist areas looking for colorful, low-maintenance perennials.

✅ Choose This Plant If...

  • You have a shady garden area that needs color.
  • You want a low-maintenance perennial that returns year after year.
  • You appreciate plants with interesting foliage and textures.
  • You want to attract pollinators to your garden.
  • You live in a region with cool, moist summers.

❌ Skip This Plant If...

  • You have a sunny, dry garden.
  • You are looking for a plant that thrives indoors.
  • You have pets that may ingest toxic plants.
📍 Ideal Location: Outdoor shade garden, woodland garden, or near a water feature.
🎨 Style: Cottage, Woodland, Traditional
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Astilbe is toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and depression. The toxic principle is unknown.
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.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

🌿

Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.

💡 Pro Tips For Comparing These Plants

Astilbe Care Tips

Astilbe is primarily an outdoor plant and requires specific conditions to thrive. Indoor cultivation is challenging due to the need for consistent moisture, high humidity, and cool temperatures. It is difficult to replicate these conditions indoors, making it an expert-level plant for indoor growing.

  • Plant in well-draining soil amended with organic matter.
  • Water regularly, especially during dry periods.
  • Apply a layer of mulch to help retain moisture and suppress weeds.
  • Divide plants every few years to prevent overcrowding.
  • Protect from intense afternoon sun to prevent leaf scorch.
❄️ Winter: Cut back foliage after it dies back in the fall. In colder climates, apply a layer of mulch to protect the rhizomes from freezing temperatures.
☀️ Summer: Ensure adequate moisture during hot weather. Provide shade during the hottest part of the day to prevent leaf scorch. Remove spent flower stalks to encourage new blooms.

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.

⚠️ Common Problems & Solutions — Plant Care Comparison

Astilbe

Common Issues: Powdery mildew, leaf spots, root rot, pests (spider mites, aphids)
Solutions: Powdery mildew: Improve air circulation, use fungicide. Leaf spots: Remove affected leaves, use fungicide. Root rot: Improve drainage, reduce watering. Pests: Insecticidal soap or neem oil.

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.

❓ Frequently Asked Questions — Comparing These Plants

Astilbe

What are the light requirements for Astilbe?

Astilbes prefer partial to full shade, requiring at least 4 hours of filtered sunlight per day. Avoid direct sunlight, especially during the hottest part of the day, as it can scorch the leaves. In hotter climates, provide more shade to prevent stress. Morning sun is generally well-tolerated, but afternoon sun can be too intense.

How do I care for Astilbe?

Astilbes thrive in partial to full shade and require moist, well-drained soil. Water regularly, especially during dry periods, to keep the soil consistently moist but not waterlogged. Apply a balanced fertilizer in early spring to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage reblooming and maintain a tidy appearance. Mulch around the base of the plant to retain moisture and suppress weeds.

How do I propagate Astilbe?

Astilbes are typically propagated by division in early spring or fall. Carefully dig up the plant and divide the root clump into smaller sections, ensuring each section has healthy roots and foliage. Replant the divisions in well-drained soil, spacing them appropriately. Water thoroughly after planting.

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.

Last updated: May 13, 2026 — Plant care data reviewed and verified by our editorial team.