Horseradish vs Rainbow Fern Plant Comparison

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

Horseradish

Horseradish

Armoracia rusticana

VS
Rainbow Fern

Rainbow Fern

Selaginella uncinata

Horseradish

Horseradish

Armoracia rusticana

Horseradish is a perennial plant cultivated primarily for its large, white, tapered root. It features large, coarse, lance-shaped leaves that can grow up to 30 cm long. It is a vigorous grower, spreading via rhizomes. While it can be grown indoors, it is primarily an outdoor plant best suited for gardens where its root can develop fully. People grow it for its pungent root, which is used as a spice and condiment.

Brassicaceae Southeastern Europe and Western Asia
✨ Features: Pungent root used as a spice
📖 Read Complete Horseradish Guide
Rainbow Fern

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.

Selaginellaceae China
✨ Features: Iridescent blue-green foliage, unique texture.
📖 Read Complete Rainbow Fern Guide

Quick Plant Comparison

Feature Horseradish Rainbow Fern
Light Full sun to partial shade Bright, indirect light. Avoid direct sunlight, which can scorch the delicate fronds.
Watering Every 7-10 days, depending on weather and soil drainage Every 2-3 days, depending on humidity and temperature
Humidity 30-50% 70-90%
Temperature 10-24°C 18-24°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height Indoors: 30-60 cm (foliage); Outdoors: 60-120 cm (foliage) 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 (mostly watering and monitoring for pests) 15-20 minutes weekly

🔬 Botanical Information — Comparing These Plants

Horseradish

Scientific Name Armoracia rusticana
Family Brassicaceae
Native To Southeastern Europe and Western Asia
Also Known As Horseradish
Leaves The leaves are large, lance-shaped, and coarse, with toothed or wavy edges. They are typically dark green and can grow up to 30 cm long.
Flowers Horseradish rarely flowers indoors. Outdoors, it may produce small, white flowers in clusters, but flowering is not common and often sterile.

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

Horseradish

Height Indoors: 30-60 cm (foliage); Outdoors: 60-120 cm (foliage)
Spread Spreads aggressively via rhizomes, potentially several meters outdoors; limited to pot size indoors.
Growth Rate Fast
Growth Pattern Horseradish grows upright with large, coarse leaves emerging from a thick, fleshy root. It spreads horizontally via rhizomes, forming new plants from the root system.

Rainbow Fern

Height 15-30 cm
Spread 30-60 cm (can spread via creeping stems)
Growth Rate Moderate
Growth Pattern Creeping and mat-forming, spreading horizontally via rhizomes. It creates a dense, low-growing carpet of foliage.

🌱 Propagation — Comparing Plant Growth

Horseradish

Methods: Root cuttings, Division

Difficulty: Easy

Tips: Take root cuttings in late fall or early spring. Plant horizontally in moist soil. For division, separate rhizomes and replant.

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

Horseradish

Horseradish is known for its intensely pungent flavor, which comes from the release of sinigrin when the root is cut or grated. It's also an aggressive spreader, making containment a key consideration.

  • ✓ Provides fresh horseradish for culinary use.
  • ✓ Relatively low-maintenance once established outdoors.
  • ✓ Can be used medicinally (though consult a professional).
  • ✓ Adds a unique flavor to dishes.
  • ✓ Attracts beneficial insects to the garden.
  • ⚠️ 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

Horseradish

Repotting Annually if grown in a container, due to aggressive rhizome growth.
Pruning Remove yellowing or damaged leaves. Trim back foliage in late fall.
Fertilizing Balanced fertilizer (10-10-10) applied in spring and summer, diluted to half strength
Seasonal Care In winter, the plant goes dormant. Reduce watering and protect from extreme cold. In spring and summer, increase watering and fertilize regularly. Harvest roots in fall or early spring.

Rainbow Fern

Repotting Every 1-2 years, or when the plant becomes root-bound. Choose a slightly larger pot.
Pruning Trim 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 shorter days.

🌞 Light Requirements

Horseradish

Full sun to partial shade

Low light tolerant: ❌ No

Rainbow Fern

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

Low light tolerant: ❌ No

💧 Watering Needs

Horseradish

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting leaves. Signs of overwatering include yellowing leaves and a mushy root.

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

Horseradish

Temperature: 10-24°C

Humidity: 30-50%

Rainbow Fern

Temperature: 18-24°C

Humidity: 70-90%

🤔 Which Plant Is Right For You?

Horseradish

Horseradish

Armoracia rusticana
Care: Expert Time: 30 minutes weekly (mostly watering and monitoring for pests) Beginner: No

Experienced gardeners who want to grow their own horseradish for culinary use and have outdoor space.

✅ Choose This Plant If...

  • You enjoy growing your own spices and condiments.
  • You have a large garden space to contain its aggressive growth.
  • You want a plant with a strong, distinctive flavor.
  • You are an experienced gardener looking for a new challenge.
  • You want a plant that is relatively pest-resistant.

❌ Skip This Plant If...

  • You have limited space, especially indoors.
  • You have pets that might ingest the plant.
  • You are a beginner gardener.
  • You dislike strong, pungent flavors.
📍 Ideal Location: Outdoors in a garden bed or large container. If indoors, a sunroom or greenhouse with very bright light.
🎨 Style: Cottage Garden, Herb Garden
🏠 Apartment Friendly: No
⚠️ Horseradish contains glucosinolates, which can cause gastrointestinal upset in dogs, cats, and horses. Symptoms include drooling, vomiting, diarrhea, and abdominal pain. All parts of the plant are potentially toxic, but the root is the most concentrated source.
Rainbow Fern

Rainbow Fern

Selaginella uncinata
Care: Expert Time: 15-20 minutes weekly Beginner: No

Experienced 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.
📍 Ideal Location: Bathroom with bright, indirect light or a terrarium.
🎨 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 Neither ideal
Pet Friendly Rainbow Fern ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Horseradish has fast growth, while Rainbow Fern grows moderate.

💡 Pro Tips For Comparing These Plants

Horseradish Care Tips

Horseradish is best grown outdoors due to its need for full sun and space for root development. Growing it indoors is challenging and requires a very large pot, bright light, and careful watering to prevent root rot. It is an aggressive spreader, so containment is crucial.

  • Plant in a designated area to control its spread.
  • Harvest roots in the fall or early spring for the best flavor.
  • Grind or grate the root immediately after harvesting for the strongest flavor.
  • Wear gloves when handling the root to avoid skin irritation.
  • Provide consistent moisture, but avoid waterlogging.
❄️ Winter: Reduce watering significantly during winter dormancy. Protect outdoor plants from extreme cold with mulch. Indoor plants still need bright light.
☀️ Summer: Provide consistent moisture during the growing season. Fertilize regularly. Monitor for pests and diseases. Ensure adequate sunlight.

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.
❄️ Winter: Reduce watering slightly, but maintain high humidity. Ensure the plant receives adequate light, supplementing with artificial light if necessary. Avoid placing near drafts or heating vents.
☀️ Summer: Water more frequently to keep the soil consistently moist. Protect from direct sunlight to prevent scorching. Increase ventilation to prevent fungal diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Horseradish

Common Issues: Root rot, Leaf spot, Aphids, White rust
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Leaf spot: Remove affected leaves and improve air circulation. Aphids: Spray with insecticidal soap. White rust: Apply a fungicide.

Rainbow Fern

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

❓ Frequently Asked Questions — Comparing These Plants

Horseradish

What are the light requirements for Horseradish?

Horseradish thrives best in full sun, requiring at least 6 hours of direct sunlight per day. However, it can tolerate partial shade, especially in hotter climates, where afternoon shade can prevent leaf scorch. Insufficient light can lead to leggy growth and reduced flower production. When planting horseradish, choose a location that receives ample sunlight throughout the day. If growing in a container, rotate the plant regularly to ensure even light exposure. Monitor the plant for signs of light stress, such as pale leaves or elongated stems, and adjust its position accordingly. Supplemental lighting may be necessary in areas with limited sunlight, especially during the winter months.

How do I care for Horseradish?

Horseradish thrives in full sun to partial shade and prefers well-drained soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize in early spring with a balanced fertilizer to promote healthy growth and flowering. Control weeds around the plant to reduce competition for nutrients. Harvest the roots in the fall or early spring, typically after the first frost. To keep the plant manageable, consider growing it in a container, as it can be quite invasive. Mulch around the base of the plant to retain moisture and suppress weeds. Monitor for pests, such as flea beetles and cabbage white butterflies, and take appropriate action if necessary. Regular care will ensure a healthy and productive horseradish plant.

How do I propagate Horseradish?

Horseradish is most commonly propagated through root cuttings. In late fall or early spring, dig up a mature plant and select healthy, pencil-thick root sections. Cut the roots into 2-3 inch pieces, ensuring each piece has at least one “eye” or bud. Plant the root cuttings horizontally, about 2-3 inches deep, in well-drained soil. Space the cuttings about 12-18 inches apart. Water thoroughly after planting and keep the soil consistently moist. New shoots should emerge within a few weeks. While less common, horseradish can also be propagated by division, separating the root mass of an established plant. Stem cuttings are not typically used for horseradish propagation.

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 14, 2026 — Plant care data reviewed and verified by our editorial team.