Cosmos vs Peacock Fern Plant Comparison

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

Cosmos

Cosmos

Cosmos bipinnatus

VS
Peacock Fern

Peacock Fern

Selaginella willdenowii

Cosmos

Cosmos

Cosmos bipinnatus

Cosmos bipinnatus is an annual flowering plant typically grown outdoors. It features delicate, fern-like foliage and daisy-like flowers in shades of pink, purple, white, and occasionally yellow or orange. Plants typically reach heights of 1 to 6 feet. Cosmos are popular for their long blooming season, attracting pollinators like bees and butterflies. They are primarily grown for ornamental purposes in gardens and meadows, adding color and texture to landscapes. While relatively easy to grow outdoors, they are not well-suited for indoor cultivation due to their high light requirements and large size.

Asteraceae Mexico
✨ Features: Attracts pollinators, long blooming season, cut flowers
📖 Read Complete Cosmos Guide
Peacock Fern

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.

Selaginellaceae Southeast Asia, Malaysia
✨ Features: Iridescent blue-green foliage.
📖 Read Complete Peacock Fern Guide

Quick Plant Comparison

Feature Cosmos Peacock Fern
Light Full sun (at least 6-8 hours of direct sunlight daily) Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds.
Watering Every 1-2 weeks, depending on weather and soil drainage Every 2-3 days, depending on humidity and temperature
Humidity 30-50% 70-90%
Temperature 18-27°C 18-24°C
Care Level Expert Moderate
Growth Rate Fast Moderate
Max Height N/A (Outdoor plant, unsuitable for indoor growing) 0.3-0.6 meters
Pet Safety ✅ Safe ✅ Safe
Soil Well-draining soil; sandy or loamy soil is ideal Well-draining, moisture-retentive mix such as peat moss, perlite, and vermiculite.
Beginner Friendly ✅ Yes With Caution
Weekly Maintenance 5 minutes weekly 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Cosmos

Scientific Name Cosmos bipinnatus
Family Asteraceae
Native To Mexico
Also Known As Cosmos, Garden Cosmos, Mexican Aster
Leaves The leaves of Cosmos bipinnatus are finely divided and fern-like, giving the plant a delicate and airy appearance. They are typically green in color and arranged oppositely along the stems. The leaves are relatively small, adding to the plant's overall graceful form.
Flowers Cosmos rarely, if ever, flower indoors due to insufficient light. Outdoors, they produce daisy-like flowers with a central disc and ray florets in shades of pink, purple, white, and occasionally yellow or orange. The flowers are typically 2-4 inches in diameter and bloom profusely throughout the summer and fall.

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.

📏 Size & Growth — Plant Comparison

Cosmos

Height N/A (Outdoor plant, unsuitable for indoor growing)
Spread N/A (Outdoor plant, unsuitable for indoor growing)
Growth Rate Fast
Growth Pattern Cosmos grow upright with branching stems. They can reach heights of 1 to 6 feet, depending on the variety. The plants produce numerous flowers on long stems, making them excellent for cutting.

Peacock Fern

Height 0.3-0.6 meters
Spread 0.3-0.6 meters
Growth Rate Moderate
Growth Pattern It grows in a spreading, bushy habit, with delicate, feathery fronds that arch gracefully. It does not climb or trail.

🌱 Propagation — Comparing Plant Growth

Cosmos

Methods: Seed

Difficulty: Easy

Tips: Sow seeds directly into the garden after the last frost or start indoors 4-6 weeks before the last frost. Lightly cover seeds with soil and keep moist until germination.

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.

✨ Benefits & Features — Comparing Plant Value

Cosmos

Cosmos are known for their delicate, fern-like foliage and daisy-like flowers that come in a variety of colors. They are also highly attractive to pollinators, making them a valuable addition to any garden. Their long blooming season provides continuous color throughout the summer and fall.

  • ✓ Attracts pollinators to your garden.
  • ✓ Provides beautiful cut flowers.
  • ✓ Adds vibrant color to your outdoor space.
  • ✓ Easy to grow and maintain.
  • ✓ Supports local ecosystems.
  • 🐾 Pet Safe

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

📅 Maintenance Schedule — Plant Care Comparison

Cosmos

Repotting N/A (Outdoor plant)
Pruning Deadheading spent flowers
Fertilizing Balanced fertilizer (10-10-10) at half strength every 4-6 weeks during the growing season
Seasonal Care Deadhead spent flowers to encourage continued blooming. In colder climates, cosmos are grown as annuals and will die with the first frost.

Peacock Fern

Repotting Every 1-2 years, or when the plant becomes root-bound.
Pruning Remove any dead or damaged fronds to maintain appearance and prevent disease.
Fertilizing Diluted liquid fertilizer (half strength) every 2-4 weeks during the growing season (spring and summer).
Seasonal Care Reduce watering slightly in winter when growth slows. Maintain humidity levels year-round. Provide supplemental light if needed during darker months.

🌞 Light Requirements

Cosmos

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

Low light tolerant: ❌ No

Peacock Fern

Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds.

Low light tolerant: ❌ No

💧 Watering Needs

Cosmos

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Cosmos are relatively drought-tolerant once established. Signs of underwatering include wilting and drooping leaves. Overwatering can cause yellowing leaves and stem rot.

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.

🌡️ Temperature & Humidity

Cosmos

Temperature: 18-27°C

Humidity: 30-50%

Peacock Fern

Temperature: 18-24°C

Humidity: 70-90%

🤔 Which Plant Is Right For You?

Cosmos

Cosmos

Cosmos bipinnatus
Care: Expert Time: 5 minutes weekly Beginner: Yes

Gardeners looking for easy-to-grow, colorful annuals that attract pollinators.

✅ Choose This Plant If...

  • You want a low-maintenance plant for your garden.
  • You want to attract butterflies and bees to your yard.
  • You need a plant that blooms for a long period.
  • You want to add vibrant colors to your outdoor space.
  • You want easy-to-grow cut flowers.

❌ Skip This Plant If...

  • You don't have a sunny outdoor space.
  • You want a plant that thrives indoors.
  • You live in a very cold climate with a short growing season.
📍 Ideal Location: Outdoor garden, meadow, or container garden in a sunny location
🎨 Style: Cottage, Bohemian, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Cosmos bipinnatus is not toxic to dogs, cats, or horses.
Peacock Fern

Peacock Fern

Selaginella willdenowii
Care: Moderate Time: 15 minutes weekly Beginner: With-caution

Experienced 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.
📍 Ideal Location: Bathroom, kitchen, or near a humidifier.
🎨 Style: Tropical, Bohemian, Eclectic
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Selaginella species are generally considered non-toxic to dogs, cats, and horses.

🎯 Quick Verdict

Best for Beginners Cosmos
Pet Friendly Both safe ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

🎯

Cosmos is rated Expert care level, while Peacock Fern is Moderate.

📈

Cosmos has fast growth, while Peacock Fern grows moderate.

💡 Pro Tips For Comparing These Plants

Cosmos Care Tips

Cosmos are easy to grow outdoors in full sun and well-draining soil. They are not suitable for indoor growing due to their high light requirements and large size. Attempting to grow them indoors will likely result in leggy, weak plants with few flowers.

  • Deadhead spent flowers regularly to encourage more blooms.
  • Provide support for taller varieties to prevent them from flopping over.
  • Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
  • Avoid over-fertilizing, as this can lead to excessive foliage growth and fewer flowers.
  • Plant in well-draining soil to prevent root rot.
❄️ Winter: Cosmos are annuals and do not survive winter in cold climates. Remove dead plants after the first frost.
☀️ Summer: Water regularly during hot, dry periods. Deadhead spent flowers to encourage continued blooming. Provide support for taller varieties to prevent them from flopping over in strong winds.

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.
❄️ Winter: Reduce watering slightly during the winter months as growth slows. Maintain humidity levels and provide supplemental light if needed.
☀️ Summer: Ensure adequate humidity and protect from direct sunlight during the summer months. Water more frequently as needed.

⚠️ Common Problems & Solutions — Plant Care Comparison

Cosmos

Common Issues: Powdery mildew, aphids, stem rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap or neem oil. Stem rot: Avoid overwatering and ensure good drainage.

Peacock Fern

Common Issues: Browning fronds, Root rot, Lack of iridescence, Pest infestations (spider mites)
Solutions: Increase humidity, ensure proper drainage, provide adequate light, treat with insecticidal soap or neem oil.

❓ Frequently Asked Questions — Comparing These Plants

Cosmos

What are the light requirements for Cosmos?

Cosmos require a minimum of six to eight hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient sunlight can result in leggy growth, weak stems, and reduced flowering. Choose a sunny location in your garden or on your balcony where the plants will receive ample sunlight throughout the day. If growing Cosmos indoors, place them near a south-facing window that provides the brightest light. Rotate the plants regularly to ensure even exposure to sunlight on all sides. If natural light is insufficient, supplement with grow lights to provide the necessary light intensity.

How do I care for Cosmos?

Cosmos thrive in full sun and well-draining soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize lightly every few weeks with a balanced fertilizer, or a bloom-boosting formula during the flowering season, to encourage abundant blooms. Deadhead spent flowers regularly to promote continuous blooming. Cosmos are generally low-maintenance plants, but they may benefit from staking if they become tall and leggy. Prune them lightly to maintain their shape and encourage bushier growth. Protect them from strong winds, which can damage the delicate stems. Monitor for pests like aphids and treat them promptly if detected. Cosmos are generally annuals, but they may self-seed in some climates.

How do I propagate Cosmos?

Cosmos are most commonly propagated by seed. Sow seeds directly into the garden in spring after the last frost, or start them indoors 6-8 weeks earlier. For division, carefully dig up the plant in early spring or fall and separate the root ball into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions immediately in well-draining soil. Stem cuttings are not a common method for Cosmos, but can be attempted by taking 4-6 inch cuttings from new growth in spring, dipping them in rooting hormone, and planting them in moist potting mix. Keiki propagation is not applicable to Cosmos.

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.

Last updated: May 1, 2026 — Plant care data reviewed and verified by our editorial team.