Delphinium vs Rainbow Fern Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Delphinium
Delphinium spp.
Delphiniums are perennial herbaceous plants known for their tall, striking flower spikes. They typically grow outdoors and are prized for their vibrant blue, purple, pink, and white flowers. The plant has deeply lobed leaves and a robust stem that supports the flower spike. They are not suited for indoor growing due to their high light requirements and size. People grow them in gardens for their aesthetic appeal and to attract pollinators.
Rainbow Fern
Selaginella uncinata
Selaginella uncinata, commonly known as Rainbow Fern, is a creeping, mat-forming plant prized for its iridescent blue-green foliage. The shimmering effect is caused by the reflection of light off the leaf surfaces. It is not a true fern, but a spikemoss. While it can be grown indoors, it requires very high humidity and consistent moisture, making it a challenging houseplant. People grow it for its unique coloration and texture, adding a touch of the exotic to terrariums or humid environments.
Quick Plant Comparison
| Feature | Delphinium | Rainbow Fern |
|---|---|---|
| Light | Full sun (at least 6 hours of direct sunlight per day) | Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds. |
| Watering | 2-3 times per week, depending on weather and soil drainage | Every 2-3 days, depending on humidity and temperature |
| Humidity | 40-60% | 70-90% |
| Temperature | 15-24°C | 18-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | Not typically grown indoors; outdoors: 0.6-1.8 meters | 15-30 cm |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining, fertile soil rich in organic matter | Well-draining, moisture-retentive mix such as peat moss, perlite, and vermiculite. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly (weeding, watering, deadheading) | 15-20 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Delphinium
| Scientific Name | Delphinium spp. |
|---|---|
| Family | Ranunculaceae |
| Native To | Northern Hemisphere, including Europe, Asia, and North America |
| Also Known As | Larkspur, Delphinium |
| Leaves | The leaves are deeply lobed and palmate, with a coarse texture. They are typically medium to dark green in color and arranged alternately along the stem. |
| Flowers | Delphiniums rarely, if ever, flower indoors. Outdoors, they produce tall, dense spikes of flowers in shades of blue, purple, pink, and white. The flowers have a distinctive spurred shape. |
Rainbow Fern
| Scientific Name | Selaginella uncinata |
|---|---|
| Family | Selaginellaceae |
| Native To | China |
| Also Known As | Rainbow Fern, Peacock Fern, Blue Fern, Spikemoss |
| Leaves | Small, scale-like leaves arranged in overlapping rows along the stems. The leaves are typically a vibrant blue-green color with an iridescent sheen. They are delicate and finely textured. |
| Flowers | Selaginella uncinata does not produce flowers in the typical sense. It reproduces via spores, which are produced in strobili (cone-like structures) at the tips of the stems. These are rarely seen indoors. |
📏 Size & Growth — Plant Comparison
Delphinium
Rainbow Fern
🌱 Propagation — Comparing Plant Growth
Delphinium
Methods: Seed, Division, Stem cuttings
Difficulty: Moderate
Tips: Sow seeds in early spring or fall. Divide established plants in spring or fall. Take stem cuttings in late spring.
Rainbow Fern
Methods: Division, Stem cuttings
Difficulty: Moderate
Tips: Divide the plant at the roots or take stem cuttings and place them in a humid environment until they root. A propagation box or terrarium works well.
✨ Benefits & Features — Comparing Plant Value
Delphinium
Delphiniums are known for their towering flower spikes, which can reach impressive heights. The intense blue color of some varieties is particularly striking and relatively rare in the plant world.
- ✓ Attracts pollinators to the garden
- ✓ Adds vibrant color and height to flower beds
- ✓ Provides cut flowers for arrangements
- ✓ Enhances the aesthetic appeal of outdoor spaces
- ✓ Can be used in traditional medicine (with caution and expert knowledge)
- ⚠️ Toxic to pets
Rainbow Fern
The Rainbow Fern's iridescent blue-green foliage sets it apart from other ferns and houseplants. This shimmering effect is a result of structural coloration, where light interacts with the leaf's surface. It is not a true fern, but a spikemoss, belonging to the genus Selaginella.
- ✓ Adds a unique visual element to indoor spaces
- ✓ Creates a calming and relaxing atmosphere
- ✓ Can be used in terrariums and vivariums
- ✓ Non-toxic to pets
- ✓ Offers a connection to nature indoors
- 🐾 Pet Safe
📅 Maintenance Schedule — Plant Care Comparison
Delphinium
Rainbow Fern
🌞 Light Requirements
Delphinium
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
Rainbow Fern
Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds.
Low light tolerant: ❌ No
💧 Watering Needs
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 a mushy stem. Underwatering results in wilting and dry, crispy leaves.
Rainbow Fern
Keep the soil consistently moist but not soggy. Water when the top of the soil feels slightly dry to the touch. Overwatering can lead to root rot, while underwatering will cause the fronds to dry out and turn brown. Use distilled or rainwater to avoid mineral buildup.
🌡️ Temperature & Humidity
Delphinium
Temperature: 15-24°C
Humidity: 40-60%
Rainbow Fern
Temperature: 18-24°C
Humidity: 70-90%
🤔 Which Plant Is Right For You?
Delphinium
Delphinium spp.Gardeners looking to add height and vibrant color to their flower beds.
✅ Choose This Plant If...
- You want a tall, dramatic flower for your garden.
- You want to attract pollinators to your yard.
- You have a sunny garden spot with well-draining soil.
- You enjoy the classic cottage garden aesthetic.
- You are an experienced gardener looking for a rewarding challenge.
❌ Skip This Plant If...
- You have limited sunlight in your home.
- You have pets or small children who might ingest the plant.
- You are a beginner gardener looking for an easy-to-grow plant.
Rainbow Fern
Selaginella uncinataExperienced plant enthusiasts who can provide a humid environment like a terrarium.
✅ Choose This Plant If...
- You want a unique and visually striking plant with iridescent foliage.
- You can provide a consistently humid environment, such as a terrarium.
- You enjoy the challenge of caring for demanding plants.
- You want to add a touch of the exotic to your indoor garden.
- You appreciate the delicate beauty of ferns and mosses.
❌ Skip This Plant If...
- You struggle to maintain consistent watering schedules.
- You live in a dry climate and cannot provide high humidity.
- You are a beginner plant owner looking for low-maintenance options.
🎯 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
Delphinium Care Tips
Delphiniums are primarily outdoor plants and are very challenging to grow indoors due to their high light requirements and need for specific temperature and humidity conditions. They require full sun, well-draining soil, and regular fertilization. Indoor cultivation is not recommended.
- Provide support for tall flower spikes to prevent them from bending or breaking.
- Deadhead spent flowers regularly to encourage more blooms.
- Protect from slugs and snails, especially young plants.
- Ensure good drainage to prevent root rot.
- Apply a layer of mulch around the base of the plant to retain moisture and suppress weeds.
Rainbow Fern Care Tips
Rainbow Ferns are challenging houseplants due to their high humidity and moisture requirements. They thrive in terrariums or enclosed environments where humidity can be maintained. Consistent watering and bright, indirect light are crucial for their survival indoors. It is primarily an outdoor plant in tropical climates.
- Use distilled or rainwater to avoid mineral buildup on the fronds.
- Maintain high humidity by misting regularly or using a humidifier.
- Provide bright, indirect light to enhance the iridescent coloration.
- Ensure good drainage to prevent root rot.
- Monitor for pests and treat promptly.
⚠️ Common Problems & Solutions — Plant Care Comparison
Delphinium
Rainbow Fern
❓ Frequently Asked Questions — Comparing These Plants
Delphinium
What are the light requirements for Delphinium?
Delphiniums are sun-loving plants and require at least six hours of direct sunlight daily to flourish. Insufficient light can lead to weak stems, poor flowering, and increased susceptibility to diseases. In hotter climates, some afternoon shade can be beneficial to prevent scorching. When selecting a location, consider the sun’s path and ensure the plants receive ample morning sun. Delphiniums grown in partial shade may still survive, but their blooms will be significantly diminished. If growing indoors, supplement with grow lights to provide the necessary intensity and duration of light. Rotate the plant regularly to ensure even light exposure.
How do I care for Delphinium?
Delphiniums require specific care to thrive. Plant in well-draining soil enriched with organic matter. Full sun (at least 6 hours daily) is crucial for optimal blooming. Water deeply but infrequently, allowing the soil to dry slightly between waterings. Fertilize regularly during the growing season with a balanced fertilizer, switching to a high-phosphorus fertilizer as buds develop to promote abundant blooms. Stake tall varieties to prevent them from collapsing under the weight of their flowers or in windy conditions. Deadhead spent blooms to encourage reblooming. Protect from slugs and snails, which can damage young plants. Provide adequate air circulation to prevent fungal diseases. Mulch around the base of the plant to retain moisture and suppress weeds.
How do I propagate Delphinium?
Delphiniums can be propagated through division, stem cuttings, and seeds. Division involves separating mature clumps in early spring or fall. Carefully dig up the plant and divide the root ball into sections, ensuring each section has healthy roots and shoots. Stem cuttings can be taken in spring. Select healthy, non-flowering stems and cut them into 4-6 inch sections. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix and keep them moist. Seeds can be sown indoors in late winter or early spring. Sow seeds thinly in a seed starting mix and keep them moist and warm. Germination typically takes 2-3 weeks.
Rainbow Fern
What are the light requirements for Rainbow Fern?
Rainbow Fern requires bright, indirect light to maintain its vibrant coloration. Direct sunlight can scorch its delicate fronds, so avoid placing it in direct sun exposure. An east-facing window is often ideal, providing gentle morning light. A north-facing window can also work, but supplemental lighting might be necessary if the plant doesn’t receive enough natural light. If placed near a south or west-facing window, use a sheer curtain to filter the light. Insufficient light can cause the colors to fade and the plant to become leggy. Observe the plant’s response to light and adjust its placement accordingly.
How do I care for Rainbow Fern?
Rainbow Fern thrives in bright, indirect light and consistently moist soil. Water thoroughly when the top inch of soil feels slightly dry, using distilled or filtered water to avoid mineral buildup. Maintain high humidity levels, ideally above 70%, through regular misting, a humidifier, or a pebble tray. Plant in a well-draining, acidic potting mix. Fertilize lightly during the growing season (spring and summer) with a diluted liquid fertilizer. Avoid direct sunlight, which can scorch the delicate foliage. Maintain temperatures between 60-75°F (15-24°C). Prune any dead or damaged fronds to encourage new growth. Ensure good air circulation to prevent fungal diseases. Repot only when necessary, usually every 1-2 years, using a slightly larger pot.
How do I propagate Rainbow Fern?
Rainbow Fern can be propagated by division or spores.
Last updated: May 2, 2026 — Plant care data reviewed and verified by our editorial team.