Peacock Fern vs Sea Holly Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Peacock Fern
Selaginella willdenowii
Selaginella willdenowii, commonly known as Peacock Fern, is a fern ally prized for its iridescent blue-green foliage. This plant is not a true fern but a spikemoss. The shimmering effect is caused by structural coloration, where light reflects off the leaf surface. It thrives in humid, shaded environments, mimicking its native rainforest habitat. While it can be grown indoors, maintaining the necessary humidity is crucial for its survival. People grow it for its unique and captivating foliage, adding a touch of exotic beauty to indoor spaces or terrariums. It is primarily an outdoor plant in tropical climates.
Sea Holly
Eryngium spp.
Sea Holly (Eryngium spp.) is a genus of perennial flowering plants known for their thistle-like appearance and metallic blue or silver foliage. Typically found in coastal and grassland habitats, they feature spiky bracts surrounding a central cone-shaped flower head. These plants are grown for their unique architectural form, drought tolerance, and long-lasting cut flowers. They are primarily outdoor plants and can be challenging to grow indoors due to their high light requirements and need for well-draining soil. Their striking appearance makes them a popular choice for xeriscaping and adding textural interest to gardens.
Quick Plant Comparison
| Feature | Peacock Fern | Sea Holly |
|---|---|---|
| Light | Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds. | Full sun (at least 6-8 hours of direct sunlight daily) |
| Watering | Every 2-3 days, depending on humidity and temperature | Every 1-2 weeks, depending on weather and soil drainage |
| Humidity | 70-90% | 30-50% |
| Temperature | 18-24°C | 15-25°C |
| Care Level | Moderate | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | 0.3-0.6 meters | Unlikely to thrive indoors, but if attempted, expect 30-60 cm |
| Pet Safety | ✅ Safe | ❌ Toxic To Pets |
| Soil | Well-draining, moisture-retentive mix such as peat moss, perlite, and vermiculite. | Well-draining, sandy or gravelly soil |
| Beginner Friendly | With Caution | ❌ No |
| Weekly Maintenance | 15 minutes weekly | 10 minutes weekly (mostly weeding and deadheading) |
🔬 Botanical Information — Comparing These Plants
Peacock Fern
| Scientific Name | Selaginella willdenowii |
|---|---|
| Family | Selaginellaceae |
| Native To | Southeast Asia, Malaysia |
| Also Known As | Peacock Fern, Willdenow's Spikemoss |
| Leaves | The leaves are small, scale-like, and densely packed along the stems. They have a shimmering, iridescent blue-green color that changes with the angle of light. The texture is delicate and slightly papery. |
| Flowers | It rarely flowers indoors. In its natural habitat, it produces spores rather than flowers. |
Sea Holly
| Scientific Name | Eryngium spp. |
|---|---|
| Family | Apiaceae |
| Native To | Europe, Mediterranean region, coastal areas worldwide |
| Also Known As | Sea Holly, Eryngo |
| Leaves | The leaves are typically deeply divided and spiny, with a leathery texture. The basal leaves are often larger than the stem leaves. The color ranges from green to blue-green, often with a silvery or metallic sheen. |
| Flowers | Sea Holly produces cone-shaped flower heads surrounded by spiky bracts. The flowers are typically blue, silver, or white and bloom in summer. It is very unlikely to flower indoors. |
📏 Size & Growth — Plant Comparison
Peacock Fern
Sea Holly
🌱 Propagation — Comparing Plant Growth
Peacock Fern
Methods: Division, Spores
Difficulty: Moderate
Tips: Divide the plant at the roots, ensuring each division has healthy fronds and roots. Plant in a moist, well-draining potting mix. For spores, sow them on a moist peat moss surface and keep them humid until germination.
Sea Holly
Methods: Seed, Root cuttings, Division
Difficulty: Moderate
Tips: Sow seeds in fall or early spring. Root cuttings should be taken in late winter. Division is best done in spring or fall.
✨ Benefits & Features — Comparing Plant Value
Peacock Fern
The iridescent blue-green foliage is its most striking feature, caused by structural coloration. It is a fern ally, not a true fern, belonging to the spikemoss family.
- ✓ Adds a unique aesthetic appeal to indoor spaces.
- ✓ Creates a calming and relaxing atmosphere.
- ✓ Can improve air quality by increasing humidity.
- ✓ Provides a sense of connection to nature.
- ✓ Offers a rewarding challenge for plant enthusiasts.
- 🐾 Pet Safe
Sea Holly
Sea Holly stands out with its metallic blue or silver foliage and thistle-like flower heads, offering a unique architectural element in gardens. Its drought tolerance and ability to thrive in poor soils make it a resilient and low-maintenance choice for challenging environments.
- ✓ Attracts pollinators to your garden.
- ✓ Provides unique textural and visual interest.
- ✓ Offers long-lasting cut flowers for arrangements.
- ✓ Drought-tolerant, reducing water consumption.
- ✓ Adds a touch of wild beauty to the landscape.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Peacock Fern
Sea Holly
🌞 Light Requirements
Peacock Fern
Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds.
Low light tolerant: ❌ No
Sea Holly
Full sun (at least 6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Peacock Fern
Keep the soil consistently moist but not waterlogged. Water when the top inch of soil feels slightly dry. 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.
Sea Holly
Water deeply when the soil is dry to the touch. Avoid overwatering, as this can lead to root rot. Sea Holly is drought-tolerant once established. Signs of underwatering include wilting and dry, crispy leaves. Overwatering can cause yellowing leaves and a mushy stem base.
🌡️ Temperature & Humidity
Peacock Fern
Temperature: 18-24°C
Humidity: 70-90%
Sea Holly
Temperature: 15-25°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Peacock Fern
Selaginella willdenowiiExperienced plant enthusiasts who can provide a humid environment.
✅ Choose This Plant If...
- You are captivated by unique foliage and iridescent colors.
- You can provide a consistently humid environment.
- You enjoy the challenge of caring for slightly more demanding plants.
- You want to add a touch of the rainforest to your home.
- You have a terrarium or greenhouse where it can thrive.
❌ Skip This Plant If...
- You struggle to maintain high humidity levels.
- You tend to overwater plants.
- You prefer low-maintenance plants.
Sea Holly
Eryngium spp.Experienced gardeners seeking a drought-tolerant and visually striking plant for outdoor gardens.
✅ Choose This Plant If...
- You want a drought-tolerant plant for a sunny garden.
- You need a plant that attracts pollinators like bees and butterflies.
- You desire a unique architectural plant with metallic blue or silver foliage.
- You want long-lasting cut flowers for arrangements.
- You have well-draining, sandy soil and full sun exposure.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You cannot provide at least 6-8 hours of direct sunlight daily.
- You tend to overwater plants.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Peacock Fern is rated Moderate care level, while Sea Holly is Expert.
💡 Pro Tips For Comparing These Plants
Peacock Fern Care Tips
Peacock Fern requires high humidity and consistent moisture, making it challenging to grow indoors without proper conditions. It needs bright, indirect light and well-draining soil. Regular misting or a humidifier is essential to maintain adequate humidity levels. It is more suited to terrariums or greenhouses.
- Maintain high humidity by misting regularly or using a humidifier.
- Use distilled or rainwater to avoid mineral buildup on the fronds.
- Provide bright, indirect light to enhance the iridescence.
- Avoid placing the plant near drafts or heat sources.
- Monitor for pests and treat promptly.
Sea Holly Care Tips
Sea Holly is primarily an outdoor plant and requires full sun and well-draining soil. Indoor cultivation is extremely challenging due to light requirements and the plant's natural habitat preferences. It is drought-tolerant and prefers lean soil. Overwatering and poor air circulation are common problems indoors.
- Ensure excellent drainage to prevent root rot.
- Provide full sun for optimal growth and flowering.
- Avoid over-fertilizing, as it can reduce flowering.
- Cut back spent flower heads to encourage more blooms.
- Protect from excessive winter moisture in colder climates.
⚠️ Common Problems & Solutions — Plant Care Comparison
Peacock Fern
Sea Holly
❓ Frequently Asked Questions — Comparing These Plants
Peacock Fern
What are the light requirements for Peacock Fern?
Peacock Fern requires bright, indirect light to maintain its vibrant color. Direct sunlight can burn its delicate fronds, causing them to turn brown and crispy. An east-facing window is ideal, providing gentle morning light. If placing it near a south- or west-facing window, use a sheer curtain to filter the light.
How do I care for Peacock Fern?
Peacock Fern thrives in bright, indirect light. Direct sunlight can scorch its delicate fronds. Maintain consistently moist soil, but avoid waterlogging. Water when the top inch of soil feels slightly dry. High humidity is crucial; aim for 60-80%. Use a humidifier, pebble tray, or group plants together to increase humidity.
How do I propagate Peacock Fern?
Peacock Fern can be propagated through division or by spores. Division is the easier method. In spring, gently remove the plant from its pot and carefully separate the root ball into smaller sections, ensuring each section has healthy fronds and roots. Plant each section in its own pot with well-draining soil. Keep the soil consistently moist and provide high humidity.
Sea Holly
What are the light requirements for Sea Holly?
Sea Holly demands abundant sunlight to flourish. Aim for a minimum of six to eight hours of direct sunlight each day. Insufficient light can result in leggy growth, reduced flowering, and duller foliage. When planting, choose a location that receives full sun exposure throughout the day. If growing in containers, position them in the sunniest spot possible, such as a south-facing patio or balcony. In regions with intense summer heat, provide some afternoon shade to prevent scorching of the foliage. Rotate potted plants regularly to ensure even light exposure on all sides, promoting balanced growth and abundant blooms.
How do I care for Sea Holly?
Sea Holly thrives in full sun and well-drained soil. Provide at least 6-8 hours of direct sunlight daily for optimal growth and flowering. Water deeply but infrequently, allowing the soil to dry out between waterings to prevent root rot. Fertilize sparingly with a low-nitrogen, high-phosphorus fertilizer in spring to encourage blooming. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of flowers. Deadhead spent blooms to promote continued flowering. Sea Holly is relatively drought-tolerant once established, making it a low-maintenance plant. Ensure good air circulation around the plant to prevent fungal diseases. Protect from excessive winter moisture in colder climates. Amend heavy clay soils with sand or gravel to improve drainage.
How do I propagate Sea Holly?
Sea Holly can be propagated through division, root cuttings, or seed. For division, carefully dig up established clumps in spring or fall and separate the roots into individual plants, ensuring each has healthy roots and foliage. Replant immediately in well-draining soil. Root cuttings can be taken in late winter or early spring. Dig up the plant and take 2-3 inch root cuttings, planting them horizontally in a sandy soil mix. Keep moist until new growth appears. Seeds can be sown in spring or fall, but may require stratification (cold treatment) for optimal germination. Sow seeds in a well-draining seed-starting mix and keep moist until germination occurs.
Last updated: April 26, 2026 — Plant care data reviewed and verified by our editorial team.