Larkspur Delphinium vs Mint Bush 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.
Mint Bush
Prostanthera rotundifolia
Prostanthera rotundifolia, commonly known as the Round-leaf Mint Bush, is an Australian native shrub prized for its aromatic foliage and profuse display of mauve to purple flowers. It typically grows to around 1-2 meters in height and width. The plant is naturally an outdoor plant, thriving in well-drained soils and full sun. People grow it for its ornamental value, attracting pollinators, and the pleasant minty fragrance released when the leaves are crushed. It is not typically grown indoors due to its high light requirements and size.
Quick Plant Comparison
| Feature | Larkspur Delphinium | Mint Bush |
|---|---|---|
| Light | Full sun | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering and growth. |
| Watering | Every 3-7 days, depending on weather and soil drainage | Every 7-10 days during the growing season, less frequently in winter. |
| Humidity | 30-50% | 30-50% |
| Temperature | 15-24°C | 15-25°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | Rarely grown indoors, outdoor height 0.3-1.8 meters | 1-2 meters (outdoor); unlikely to thrive indoors. |
| 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 sandy loam or gravelly soil. A mix of potting mix, perlite, and sand is suitable. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly (weeding, watering, deadheading) | 30 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. |
Mint Bush
| Scientific Name | Prostanthera rotundifolia |
|---|---|
| Family | Lamiaceae |
| Native To | Australia |
| Also Known As | Round-leaf Mint Bush, Native Mint |
| Leaves | The leaves are small, rounded, and approximately 1-2 cm in diameter. They are a deep green color and have a slightly rough texture. When crushed, the leaves release a strong minty fragrance. |
| Flowers | The Round-leaf Mint Bush produces masses of mauve to purple flowers in spring and summer. The flowers are small and bell-shaped, and they are arranged in clusters along the branches. Flowering is unlikely indoors. |
📏 Size & Growth — Plant Comparison
Larkspur Delphinium
Mint Bush
🌱 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.
Mint Bush
Methods: Stem cuttings, Seed
Difficulty: Moderate
Tips: Take semi-hardwood cuttings in spring or summer. Dip the cut end in rooting hormone and plant in well-draining potting mix. Keep the cuttings moist and in a warm location until roots develop. Seeds can be sown in spring after a period of cold stratification.
✨ 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
Mint Bush
The Round-leaf Mint Bush is unique for its highly aromatic foliage and profuse display of mauve to purple flowers. Its drought tolerance and ability to attract pollinators make it a valuable addition to native gardens.
- ✓ Attracts pollinators
- ✓ Adds fragrance to the garden
- ✓ Provides visual interest with its flowers
- ✓ Drought-tolerant once established
- ✓ Supports local ecosystems
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Larkspur Delphinium
Mint Bush
🌞 Light Requirements
Larkspur Delphinium
Full sun
Low light tolerant: ❌ No
Mint Bush
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering and growth.
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.
Mint Bush
Water deeply when the top inch of soil feels dry. Avoid overwatering, as this can lead to root rot. In well-draining soil, it can tolerate short periods of dryness. Signs of underwatering include wilting leaves and dry, brittle stems. Overwatering signs include yellowing leaves and a musty smell from the soil.
🌡️ Temperature & Humidity
Larkspur Delphinium
Temperature: 15-24°C
Humidity: 30-50%
Mint Bush
Temperature: 15-25°C
Humidity: 30-50%
🤔 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.
Mint Bush
Prostanthera rotundifoliaExperienced gardeners looking for an aromatic and visually appealing shrub for their outdoor garden.
✅ Choose This Plant If...
- You want an aromatic shrub for your garden
- You want to attract pollinators to your yard
- You have a sunny location with well-drained soil
- You appreciate Australian native plants
- You are an experienced gardener looking for a rewarding challenge.
❌ Skip This Plant If...
- You have limited sunlight indoors
- You have pets that may ingest the plant
- You are a beginner gardener
- You live in a very cold climate with frequent frosts.
🎯 Quick Verdict
⚡ 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
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.
Mint Bush Care Tips
The Round-leaf Mint Bush is primarily an outdoor plant that requires full sun and well-drained soil. It is challenging to grow indoors due to its high light requirements and need for good air circulation. Regular pruning is necessary to maintain its shape and encourage flowering. It is also toxic to pets.
- Provide well-draining soil to prevent root rot.
- Prune regularly to maintain shape and encourage flowering.
- Water deeply but infrequently, allowing the soil to dry out between waterings.
- Protect from frost in colder climates.
- Fertilize in spring with a balanced slow-release fertilizer.
⚠️ Common Problems & Solutions — Plant Care Comparison
Larkspur Delphinium
Mint Bush
❓ 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.
Mint Bush
What are the light requirements for Mint Bush?
Mint Bush requires bright, indirect light to thrive. An east-facing window is ideal, providing gentle morning sun. A west-facing window can also work, but shield the plant from intense afternoon sun. Insufficient light will result in leggy growth and reduced flowering. South-facing windows may be too intense, requiring sheer curtains to diffuse the light.
How do I care for Mint Bush?
Mint Bush thrives in bright, indirect light; direct sunlight can scorch its leaves. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels, especially during drier months. Fertilize regularly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength, to encourage blooming.
How do I propagate Mint Bush?
Mint Bush can be propagated through stem cuttings. Take 4-6 inch cuttings from healthy stems, removing the lower leaves. Dip the cut end in rooting hormone and plant in a well-draining potting mix. Keep the soil consistently moist and provide bright, indirect light. Roots should develop in a few weeks.
Last updated: April 21, 2026 — Plant care data reviewed and verified by our editorial team.