Cestrum vs Larkspur Delphinium Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Cestrum
Cestrum nocturnum
Cestrum nocturnum, commonly known as Night-blooming jasmine, is a fast-growing evergreen shrub that can reach up to 12 feet tall outdoors. It is prized for its intensely fragrant flowers that bloom at night, releasing a sweet, powerful scent. The plant features slender, willow-like leaves and produces small, creamy-white flowers in clusters. While it can be grown in containers, it is primarily an outdoor plant and may struggle to thrive indoors due to its high light requirements and potential size. People grow it for its unique nocturnal fragrance and attractive foliage.
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.
Quick Plant Comparison
| Feature | Cestrum | Larkspur Delphinium |
|---|---|---|
| Light | Full sun to partial shade outdoors. Requires at least 6 hours of direct sunlight for optimal flowering. | Full sun |
| Watering | Every 3-7 days during the growing season, less frequently in winter. | Every 3-7 days, depending on weather and soil drainage |
| Humidity | 40-60% | 30-50% |
| Temperature | 18-27°C | 15-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | Up to 12 feet outdoors, 3-6 feet in a container. | Rarely grown indoors, outdoor height 0.3-1.8 meters |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining potting mix amended with compost or other organic matter. | Well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.0) |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly | 30 minutes weekly (weeding, watering, deadheading) |
🔬 Botanical Information — Comparing These Plants
Cestrum
| Scientific Name | Cestrum nocturnum |
|---|---|
| Family | Solanaceae |
| Native To | West Indies |
| Also Known As | Night-blooming jasmine, Lady of the Night, Queen of the Night |
| Leaves | The leaves are lanceolate to ovate, smooth, and glossy green. They are typically 4-6 inches long and 1-2 inches wide, with a slightly wavy margin. The leaves are arranged alternately along the stems. |
| Flowers | It rarely flowers indoors. Outdoors, the flowers are small, tubular, and creamy-white, appearing in clusters at the ends of branches. They are highly fragrant, especially at night. |
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
Cestrum
Larkspur Delphinium
🌱 Propagation — Comparing Plant Growth
Cestrum
Methods: Stem cuttings, Seed
Difficulty: Easy
Tips: Take stem cuttings in spring or summer. Dip the cut end in rooting hormone and plant in moist potting mix. Keep the soil consistently moist until roots develop. Seeds can be sown in spring after soaking them in water for 24 hours.
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
Cestrum
The most unique characteristic is its intense fragrance that is released at night. The flowers are relatively inconspicuous during the day, making the nocturnal fragrance a surprising and delightful feature.
- ✓ Provides intense fragrance, especially at night
- ✓ Attracts pollinators like moths
- ✓ Adds a tropical aesthetic to gardens
- ✓ Can be used as a privacy screen or hedge
- ✓ Offers visual interest with its foliage and flowers
- ⚠️ 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
Cestrum
Larkspur Delphinium
🌞 Light Requirements
Cestrum
Full sun to partial shade outdoors. Requires at least 6 hours of direct sunlight for optimal flowering.
Low light tolerant: ❌ No
Larkspur Delphinium
Full sun
Low light tolerant: ❌ No
💧 Watering Needs
Cestrum
Water thoroughly when the top inch of soil is dry. Avoid overwatering, which can lead to root rot. During the growing season (spring and summer), water more frequently. Reduce watering in the fall and winter. Signs of overwatering include yellowing leaves and soggy soil. Underwatering is indicated by wilting leaves and dry 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
Cestrum
Temperature: 18-27°C
Humidity: 40-60%
Larkspur Delphinium
Temperature: 15-24°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Cestrum
Cestrum nocturnumGardeners with outdoor space who appreciate fragrant flowers and are aware of the plant's toxicity.
✅ Choose This Plant If...
- You want a plant with an incredibly strong, sweet fragrance, especially at night.
- You have a sunny outdoor space where it can thrive.
- You are experienced with plant care and can manage its needs.
- You are willing to take precautions to protect pets and children from its toxicity.
- You enjoy pruning and shaping plants to maintain their desired form.
❌ Skip This Plant If...
- You have pets or small children who might ingest the plant.
- You lack a sunny outdoor space.
- You are looking for a low-maintenance indoor plant.
- You are sensitive to strong fragrances.
- You live in a climate with harsh winters and cannot provide adequate protection.
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.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Cestrum has fast growth, while Larkspur Delphinium grows moderate.
💡 Pro Tips For Comparing These Plants
Cestrum Care Tips
Cestrum nocturnum is primarily an outdoor plant that requires full sun and well-draining soil. It can be challenging to grow indoors due to its high light requirements and potential size. Regular pruning is necessary to maintain its shape and encourage flowering. Toxicity to pets is a major concern.
- Provide at least 6 hours of direct sunlight daily for optimal flowering.
- Water deeply but allow the soil to dry slightly between waterings.
- Fertilize regularly during the growing season with a balanced fertilizer.
- Prune after flowering to encourage new growth and maintain shape.
- Protect from frost in colder climates by bringing indoors or covering with frost cloth.
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.
⚠️ Common Problems & Solutions — Plant Care Comparison
Cestrum
Larkspur Delphinium
❓ Frequently Asked Questions — Comparing These Plants
Cestrum
What are the light requirements for Cestrum?
Cestrum plants are sun-loving and require ample sunlight to thrive and produce abundant blooms. Ideally, they should receive at least 6 hours of direct sunlight each day. Inadequate sunlight can lead to leggy growth, reduced flowering, and pale foliage. When growing Cestrum indoors, place it near a south-facing window where it can receive maximum light exposure. If sufficient natural light is not available, consider supplementing with grow lights. Rotate the plant regularly to ensure even light exposure on all sides. During the summer months, Cestrum can be moved outdoors to a sunny location, but acclimate it gradually to prevent sunburn.
How do I care for Cestrum?
Cestrum thrives in well-draining soil and requires regular watering, especially during the growing season. Allow the top inch of soil to dry out between waterings to prevent root rot. Provide a sunny location with at least 6 hours of direct sunlight daily for optimal flowering. Fertilize regularly with a balanced fertilizer during the growing season (spring and summer) to encourage abundant blooms. Prune after flowering to maintain shape and promote new growth. Cestrum benefits from consistent humidity. Monitor for pests like aphids and spider mites, and treat promptly. Ensure good air circulation to prevent fungal diseases. In colder climates, Cestrum may need to be brought indoors or protected from frost. Repot every 1-2 years as needed. Pinch back new growth to encourage bushier growth.
How do I propagate Cestrum?
Cestrum can be propagated using stem cuttings. Take a 4-6 inch cutting from a healthy stem, removing the lower leaves. Dip the cut end in rooting hormone and plant it in a well-draining potting mix. Keep the soil moist and provide indirect light. Roots should develop in a few weeks. Division is possible for some clump-forming varieties. Carefully separate the plant at the root ball and repot each section. Keiki propagation is not applicable to Cestrum. Cuttings are best taken in spring or early summer. Maintain high humidity around the cuttings to encourage rooting. Provide bottom heat for faster root development. Once rooted, gradually acclimate the new plants to brighter light.
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: April 29, 2026 — Plant care data reviewed and verified by our editorial team.