Fountain Grass vs Interrupted Fern Plant Comparison

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

Fountain Grass

Fountain Grass

Pennisetum setaceum

VS
Interrupted Fern

Interrupted Fern

Osmunda claytoniana

Fountain Grass

Fountain Grass

Pennisetum setaceum

Fountain Grass is a perennial grass known for its graceful, arching foliage and bottlebrush-like flower plumes. Typically grown as an ornamental grass, it adds texture and movement to landscapes. It forms dense clumps of slender, linear leaves that can range in color from green to reddish-purple, depending on the cultivar. The feathery flower plumes emerge in summer and persist into fall, adding visual interest. While primarily an outdoor plant, it is sometimes grown in containers. It is valued for its drought tolerance and low maintenance requirements in suitable climates.

Poaceae Native to tropical Africa, Southwest Asia, and the Arabian Peninsula; naturalized in many other regions.
✨ Features: Drought tolerance, attractive flower plumes, adds texture and movement to landscapes.
📖 Read Complete Fountain Grass Guide
Interrupted Fern

Interrupted Fern

Osmunda claytoniana

The Interrupted Fern is a deciduous fern characterized by its unique fronds. It's primarily an outdoor plant, native to moist woodlands and stream banks. The 'interrupted' name comes from the fertile pinnae located in the middle of the frond, which wither and drop off, leaving a gap. The fronds are initially upright, arching gracefully as they mature. People cultivate it for its textural interest and naturalistic beauty in shade gardens and woodland settings. It is not well-suited for indoor cultivation due to its size and specific environmental needs.

Osmundaceae Eastern North America, Eastern Asia
✨ Features: Unique interrupted fronds, provides habitat for wildlife, adds textural interest to shade gardens.
📖 Read Complete Interrupted Fern Guide

Quick Plant Comparison

Feature Fountain Grass Interrupted Fern
Light Full sun (at least 6-8 hours of direct sunlight daily) Partial shade to full shade. Requires protection from direct sunlight, especially during the hottest part of the day.
Watering Every 1-2 weeks, depending on weather and soil drainage 2-3 times per week, depending on weather and soil drainage
Humidity 30-50% 50-70%
Temperature 18-30°C 10-24°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height 0.6-1.5 meters (outdoor); significantly smaller in containers indoors (if attempted) 0.6-1.5 meters (2-5 feet)
Pet Safety ✅ Safe ✅ Safe
Soil Well-draining soil, such as a sandy loam or a general-purpose potting mix amended with perlite. Rich, well-draining, slightly acidic soil. A mix of peat moss, compost, and loam is ideal.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes monthly 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Fountain Grass

Scientific Name Pennisetum setaceum
Family Poaceae
Native To Native to tropical Africa, Southwest Asia, and the Arabian Peninsula; naturalized in many other regions.
Also Known As Fountain Grass, Crimson Fountain Grass, Purple Fountain Grass
Leaves Slender, linear leaves that can range in color from green to reddish-purple, depending on the cultivar. The leaves are typically 30-90 cm long and 0.5-1 cm wide.
Flowers Flowers are produced in bottlebrush-like plumes that can be pink, purple, or white. The plumes emerge in summer and persist into fall. It is very unlikely to flower indoors.

Interrupted Fern

Scientific Name Osmunda claytoniana
Family Osmundaceae
Native To Eastern North America, Eastern Asia
Also Known As Interrupted Fern, Clayton's Fern
Leaves The fronds are bipinnately compound, meaning the leaflets (pinnae) are further divided into smaller segments (pinnules). The sterile pinnae are a vibrant green, while the fertile pinnae are initially green but turn brown and wither, leaving a gap in the middle of the frond. The fronds can reach up to 1.5 meters (5 feet) in length.
Flowers Ferns do not produce flowers. They reproduce via spores.

📏 Size & Growth — Plant Comparison

Fountain Grass

Height 0.6-1.5 meters (outdoor); significantly smaller in containers indoors (if attempted)
Spread 0.6-1.2 meters (outdoor); spreads via seeds and can be invasive in some regions.
Growth Rate Fast
Growth Pattern Forms dense clumps of arching, linear leaves. Flower plumes emerge from the center of the clump and arch outwards.

Interrupted Fern

Height 0.6-1.5 meters (2-5 feet)
Spread 0.6-1 meter (2-3 feet), spreads slowly via rhizomes
Growth Rate Moderate
Growth Pattern Upright, arching fronds emerge from a slowly spreading rhizome. The fronds are initially erect, then arch gracefully as they mature, creating a vase-like shape.

🌱 Propagation — Comparing Plant Growth

Fountain Grass

Methods: Seed, Division

Difficulty: Easy

Tips: Divide established clumps in spring or fall. Sow seeds in spring after the last frost. Ensure good drainage and consistent moisture during germination.

Interrupted Fern

Methods: Spores, Division

Difficulty: Moderate

Tips: Division is best done in early spring or fall. Carefully separate the rhizomes, ensuring each section has healthy roots and fronds. Spores require a sterile environment and consistent moisture to germinate.

✨ Benefits & Features — Comparing Plant Value

Fountain Grass

Fountain Grass is known for its graceful, arching foliage and bottlebrush-like flower plumes. The flower plumes add visual interest and movement to landscapes. Its drought tolerance makes it a popular choice for xeriscaping.

  • ✓ Adds visual interest to landscapes
  • ✓ Provides habitat for birds and beneficial insects
  • ✓ Drought-tolerant and low-maintenance
  • ✓ Erosion control on slopes
  • ✓ Can be used in cut flower arrangements
  • 🐾 Pet Safe

Interrupted Fern

The Interrupted Fern is unique due to the fertile pinnae located in the middle of the frond, which wither and drop off, leaving a gap. This gives the frond its distinctive 'interrupted' appearance. The plant also has a bold, upright growth habit that makes it a striking addition to any shade garden.

  • ✓ Adds textural interest to the garden
  • ✓ Provides habitat for wildlife
  • ✓ Creates a naturalistic and calming atmosphere
  • ✓ Enhances the beauty of shady areas
  • ✓ Can be used in medicinal applications (historically)
  • 🐾 Pet Safe

📅 Maintenance Schedule — Plant Care Comparison

Fountain Grass

Repotting Not typically repotted if grown outdoors. If grown in containers, repot every 1-2 years in spring.
Pruning Cut back foliage in late winter or early spring before new growth emerges. Deadhead spent flower plumes to maintain appearance and prevent unwanted seed dispersal.
Fertilizing Apply a balanced slow-release fertilizer in spring. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of flowering.
Seasonal Care In winter, cut back foliage to a few inches above the ground in colder climates. In summer, ensure adequate watering during dry spells.

Interrupted Fern

Repotting Not applicable for outdoor planting. If grown in a container (not recommended), repot every 2-3 years in early spring.
Pruning Remove dead or damaged fronds as needed. No other pruning is necessary.
Fertilizing Apply a slow-release, balanced fertilizer in early spring. Avoid over-fertilizing, as it can damage the roots.
Seasonal Care In spring, apply fertilizer and remove any dead fronds. In summer, ensure consistent moisture. In fall, the fronds will turn brown and die back. In winter, the plant is dormant and requires minimal care.

🌞 Light Requirements

Fountain Grass

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

Low light tolerant: ❌ No

Interrupted Fern

Partial shade to full shade. Requires protection from direct sunlight, especially during the hottest part of the day.

Low light tolerant: ❌ No

💧 Watering Needs

Fountain Grass

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Allow the soil to dry out slightly between waterings. Signs of underwatering include drooping or browning leaves. Overwatering can cause yellowing leaves and a mushy base.

Interrupted Fern

Requires consistently moist soil. Water deeply when the top inch of soil feels dry. Overwatering can lead to root rot, especially in poorly draining soil. Underwatering will cause the fronds to dry out and brown.

🌡️ Temperature & Humidity

Fountain Grass

Temperature: 18-30°C

Humidity: 30-50%

Interrupted Fern

Temperature: 10-24°C

Humidity: 50-70%

🤔 Which Plant Is Right For You?

Fountain Grass

Fountain Grass

Pennisetum setaceum
Care: Expert Time: 15 minutes monthly Beginner: No

Gardeners looking for a low-maintenance, ornamental grass to add texture and movement to their outdoor landscapes.

✅ Choose This Plant If...

  • You want a drought-tolerant ornamental grass for your garden.
  • You appreciate the graceful, arching foliage and feathery flower plumes.
  • You are looking for a low-maintenance plant that adds texture and movement to your landscape.
  • You live in a warm climate where it can thrive outdoors.
  • You want to attract birds to your garden.

❌ Skip This Plant If...

  • You live in a region where it is considered an invasive species.
  • You do not have a sunny outdoor space.
  • You are looking for a plant that thrives indoors.
📍 Ideal Location: Outdoor garden beds, borders, or containers in a sunny location.
🎨 Style: Mediterranean, Cottage, Modern, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Pennisetum species are not listed as toxic to dogs, cats, or horses.
Interrupted Fern

Interrupted Fern

Osmunda claytoniana
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners with shady, moist areas who want a naturalistic, textural element in their landscape.

✅ Choose This Plant If...

  • You have a shady, moist garden area.
  • You want a unique and textural fern.
  • You want to attract wildlife to your garden.
  • You appreciate the naturalistic beauty of woodland plants.
  • You are an experienced gardener looking for a rewarding challenge.

❌ Skip This Plant If...

  • You have limited space.
  • You cannot provide consistently moist conditions.
  • You want a low-maintenance plant.
📍 Ideal Location: Shady woodland garden, moist stream bank, or shaded patio (in a large container, though not ideal)
🎨 Style: Woodland, Naturalistic, Cottage Garden
🏠 Apartment Friendly: No
⚠️ According to available sources, Osmunda species are generally considered non-toxic to humans and animals. However, it's always best to prevent pets from consuming any plant material.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Both safe ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Fountain Grass has fast growth, while Interrupted Fern grows moderate.

💡 Pro Tips For Comparing These Plants

Fountain Grass Care Tips

Fountain Grass is primarily an outdoor plant that thrives in full sun and well-draining soil. Growing it indoors is challenging due to its high light requirements and potential size. It requires careful watering and fertilization. It can become invasive in some regions due to its prolific seed production.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for optimal growth and flowering.
  • Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
  • Cut back foliage in late winter or early spring to encourage new growth.
  • Deadhead spent flower plumes to prevent unwanted seed dispersal.
❄️ Winter: In colder climates, cut back foliage to a few inches above the ground in late winter or early spring. Mulch around the base of the plant to protect the roots from freezing temperatures.
☀️ Summer: Ensure adequate watering during dry spells. Deadhead spent flower plumes to maintain appearance and prevent unwanted seed dispersal. Monitor for pests and diseases.

Interrupted Fern Care Tips

Interrupted Fern is primarily an outdoor plant that requires consistently moist, shaded conditions. Indoor cultivation is challenging due to its size and humidity needs. It needs rich, acidic soil and protection from direct sunlight. Regular watering and occasional fertilization are essential for healthy growth.

  • Provide consistent moisture, especially during dry periods.
  • Amend the soil with plenty of organic matter.
  • Protect from direct sunlight.
  • Fertilize in early spring with a slow-release fertilizer.
  • Monitor for pests and diseases regularly.
❄️ Winter: The fronds will die back in winter. Remove any dead fronds to prevent disease. The plant is dormant during this time and requires minimal watering.
☀️ Summer: Ensure consistent moisture during the summer months, especially during dry periods. Provide shade to protect the fronds from scorching. Monitor for pests and diseases regularly.

⚠️ Common Problems & Solutions — Plant Care Comparison

Fountain Grass

Common Issues: Root rot, Rust, Aphids, Seed dispersal (invasive potential)
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Rust: Improve air circulation and apply a fungicide if necessary. Aphids: Spray with insecticidal soap. Seed dispersal: Deadhead flower plumes before seeds mature to prevent unwanted spread.

Interrupted Fern

Common Issues: Frond browning, Root rot, Pest infestations (slugs, snails)
Solutions: Frond browning: Increase humidity and ensure consistent watering. Root rot: Improve soil drainage and reduce watering frequency. Pest infestations: Handpick pests or use organic pest control methods.

❓ Frequently Asked Questions — Comparing These Plants

Fountain Grass

What are the light requirements for Fountain Grass?

Fountain Grass requires a minimum of six hours of direct sunlight each day to thrive and produce abundant blooms. Insufficient light can lead to weak growth, fewer flowers, and a generally unhealthy appearance. When planting Fountain Grass, choose a location that receives full sun exposure throughout the day.

How do I care for Fountain Grass?

Fountain Grass thrives in full sun and well-drained soil. Water deeply but infrequently, allowing the soil to dry out slightly between waterings. Fertilize in spring with a balanced fertilizer to promote healthy growth and abundant blooms. Prune back dead foliage in late winter or early spring before new growth emerges.

How do I propagate Fountain Grass?

Fountain Grass is easily propagated by division. In early spring, carefully dig up the clump and divide it into smaller sections, ensuring each section has healthy roots and foliage. Replant the divisions in well-drained soil and water thoroughly. Stem cuttings are not a reliable method. Keikis do not naturally occur on Fountain Grass.

Interrupted Fern

What are the light requirements for Interrupted Fern?

Interrupted Ferns thrive in bright, indirect light. Direct sunlight can scorch their delicate fronds, leading to browning and damage. An east-facing window is ideal, providing gentle morning light. A north-facing window can also work, but may require supplemental grow lights if the fern isn’t receiving enough light.

How do I care for Interrupted Fern?

Interrupted Ferns require consistent moisture and high humidity to thrive. Plant in well-draining, acidic soil rich in organic matter. Water regularly to keep the soil consistently moist, but not waterlogged. Provide bright, indirect light; avoid direct sunlight, which can scorch the fronds.

How do I propagate Interrupted Fern?

Interrupted Ferns can be propagated through division or by spores. Division is the easier method. In early spring, carefully dig up the fern and gently separate the rhizomes into smaller clumps, ensuring each clump has healthy fronds and roots. Replant the divisions in well-draining, acidic soil and keep them consistently moist.

Last updated: May 9, 2026 — Plant care data reviewed and verified by our editorial team.