Citronella vs Larkspur Delphinium Plant Comparison

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

Citronella

Citronella

Cymbopogon nardus or Cymbopogon winterianus

VS
Larkspur Delphinium

Larkspur Delphinium

Delphinium spp.

Citronella

Citronella

Cymbopogon nardus or Cymbopogon winterianus

Citronella is a perennial clumping grass known for its distinct citrusy scent, primarily due to the presence of citronellal and geraniol in its leaves. It typically grows to a height of 3-6 feet. It's primarily grown outdoors for its mosquito-repelling properties, although the effectiveness is debated and requires crushing the leaves to release the oils. It is not naturally an indoor plant and requires very specific conditions to thrive indoors.

Poaceae (Grass family) Asia (Sri Lanka, India, Indonesia)
✨ Features: Citrus-scented foliage, mosquito-repelling properties (when crushed).
📖 Read Complete Citronella 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 Citronella Larkspur Delphinium
Light Full sun (at least 6-8 hours of direct sunlight daily) Full sun
Watering Every 3-7 days depending on weather and soil drainage. Every 3-7 days, depending on weather and soil drainage
Humidity 40-60% 30-50%
Temperature 18-30°C 15-24°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height 1-2 meters outdoors, significantly smaller indoors (0.3-0.6 meters) Rarely grown indoors, outdoor height 0.3-1.8 meters
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining loamy soil 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

Citronella

Scientific Name Cymbopogon nardus or Cymbopogon winterianus
Family Poaceae (Grass family)
Native To Asia (Sri Lanka, India, Indonesia)
Also Known As Citronella grass, Nardus grass, Mana grass
Leaves The leaves are long, slender, and green, with a rough texture. They are typically 1-3 cm wide and up to 1 meter long. When crushed, the leaves release a strong citrus scent.
Flowers Citronella rarely flowers indoors. Outdoors, it produces panicles of small, inconspicuous flowers.

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

Citronella

Height 1-2 meters outdoors, significantly smaller indoors (0.3-0.6 meters)
Spread 0.5-1 meter, clumping growth habit
Growth Rate Fast
Growth Pattern Citronella grows in clumps, with upright stems reaching several feet in height. It spreads through rhizomes, but is not considered highly invasive.

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

Citronella

Methods: Division, Seed

Difficulty: Easy

Tips: Divide established clumps in spring or early summer. Ensure each division has healthy roots and shoots. Plant in well-draining soil and water thoroughly.

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

Citronella

The strong citrus scent is the most unique characteristic. The plant's mosquito-repelling properties, though debated, are also a key feature. It is a fast-growing grass that can quickly fill in garden spaces.

  • ✓ Natural mosquito repellent (when crushed)
  • ✓ Pleasant citrus scent
  • ✓ Fast-growing ground cover
  • ✓ Adds texture and movement to the garden
  • ✓ Relatively easy to propagate
  • ⚠️ 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

Citronella

Repotting Repot every 1-2 years in spring if grown in a container, or when the plant becomes root-bound.
Pruning Trim dead or yellowing leaves regularly. Cut back the plant in late winter or early spring to encourage new growth.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season (spring/summer).
Seasonal Care During the growing season (spring/summer), water more frequently and fertilize regularly. In winter, reduce watering and withhold fertilizer. Protect from frost.

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

Citronella

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Larkspur Delphinium

Full sun

Low light tolerant: ❌ No

💧 Watering Needs

Citronella

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Allow soil to drain freely. Signs of underwatering include drooping or browning leaves. Overwatering can cause yellowing leaves and a musty smell from the 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

Citronella

Temperature: 18-30°C

Humidity: 40-60%

Larkspur Delphinium

Temperature: 15-24°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Citronella

Citronella

Cymbopogon nardus or Cymbopogon winterianus
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners with outdoor space looking for a natural mosquito repellent (though effectiveness is limited).

✅ Choose This Plant If...

  • You want a natural mosquito repellent for your garden (though effectiveness is limited).
  • You enjoy the citrusy scent of the foliage.
  • You have a sunny outdoor space.
  • You are experienced with plant care and can provide the specific conditions needed.
  • You want a fast-growing grass for your garden.

❌ Skip This Plant If...

  • You don't have a sunny outdoor space.
  • You have pets that might ingest the plant.
  • You are looking for a low-maintenance indoor plant.
  • You are sensitive to strong scents.
  • You live in a climate with harsh winters.
📍 Ideal Location: Sunny outdoor garden or patio.
🎨 Style: Tropical, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, citronella contains essential oils that are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, increased salivation, and dermatitis.
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

☀️

Citronella needs full sun (at least 6-8 hours of direct sunlight daily), while Larkspur Delphinium prefers full sun.

📈

Citronella has fast growth, while Larkspur Delphinium grows moderate.

💡 Pro Tips For Comparing These Plants

Citronella Care Tips

Citronella is primarily an outdoor plant. Growing it indoors is challenging due to its high light requirements. It needs full sun, well-draining soil, and careful watering to avoid root rot. It is also toxic to pets, so keep it out of reach.

  • Plant in well-draining soil to prevent root rot.
  • Provide at least 6-8 hours of direct sunlight daily.
  • Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
  • Fertilize regularly during the growing season.
  • Protect from frost in colder climates.
❄️ Winter: In colder climates, protect citronella from frost by bringing it indoors (though it will likely struggle) or covering it with a frost blanket. Reduce watering significantly.
☀️ Summer: Water more frequently during the summer months, especially during hot, dry weather. Fertilize regularly to promote healthy growth. Ensure adequate sunlight.

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

Citronella

Common Issues: Root rot, spider mites, insufficient sunlight
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Spider mites: Treat with insecticidal soap or neem oil. Insufficient sunlight: Provide supplemental lighting or move the plant outdoors during the growing season.

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

Citronella

What are the light requirements for Citronella?

Citronella plants need a good amount of sunlight to thrive. Aim for at least 6 hours of direct sunlight per day for optimal growth and mosquito-repelling potency. If growing indoors, place the plant near a sunny window, preferably south-facing. If natural light is insufficient, supplement with grow lights.

How do I care for Citronella?

Citronella plants thrive in well-draining soil and prefer full sun to partial shade. Water regularly, allowing the soil to dry slightly between waterings. Avoid overwatering, which can lead to root rot. Fertilize every 4-6 weeks during the growing season (spring and summer) with a balanced fertilizer to promote healthy growth and flowering.

How do I propagate Citronella?

Citronella can be propagated through several methods. Division involves separating the plant into smaller clumps and repotting them. Stem cuttings can be taken from healthy stems and rooted in water or soil. Keikis, or baby plants, sometimes form on mature plants and can be carefully removed and potted.

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 3, 2026 — Plant care data reviewed and verified by our editorial team.