Australian Tree Fern vs Purple Fountain Grass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Australian Tree Fern
Cyathea cooperi
The Australian Tree Fern (Cyathea cooperi) is a fast-growing tree fern characterized by its elegant, arching fronds and distinctive trunk covered in brown scales. It's primarily an outdoor plant, thriving in humid, subtropical environments. Its large size and specific environmental needs make it challenging to grow indoors long-term. People grow it for its tropical appearance and architectural interest in gardens and landscapes. It can reach impressive heights in its natural habitat. The plant's beauty lies in its delicate-looking but resilient fronds.
Purple Fountain Grass
Pennisetum setaceum 'Rubrum'
Purple Fountain Grass is a striking ornamental grass prized for its arching, burgundy-purple foliage and bottlebrush-like flower plumes. It typically grows in a mounded form, reaching several feet in height and width. While technically a perennial in warmer climates, it is often grown as an annual in cooler regions due to its sensitivity to frost. It is primarily an outdoor plant, grown for its dramatic texture and color in gardens and landscapes. People grow it for its ornamental value, adding movement and visual interest to borders, containers, and mass plantings.
Quick Plant Comparison
| Feature | Australian Tree Fern | Purple Fountain Grass |
|---|---|---|
| Light | Bright, indirect light to partial shade. Avoid direct sunlight, especially during the hottest part of the day. | Full sun (at least 6 hours of direct sunlight per day) |
| Watering | Every 2-4 days, depending on environmental conditions and pot size. | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 60-80% | 20-50% |
| Temperature | 18-24°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | Indoors: 1-2 meters (difficult to maintain this size long-term) | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters |
| Pet Safety | ✅ Safe | ✅ Safe |
| Soil | Well-draining, slightly acidic soil rich in organic matter. A mix of peat moss, perlite, and tree fern fiber is ideal. | Well-draining soil, such as a sandy loam or a potting mix amended with perlite |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Australian Tree Fern
| Scientific Name | Cyathea cooperi |
|---|---|
| Family | Cyatheaceae |
| Native To | Eastern Australia (New South Wales and Queensland) |
| Also Known As | Australian Tree Fern, Cooper's Cyathea, Lacy Tree Fern |
| Leaves | Large, lacy, bright green fronds that can reach up to 4 meters in length. The fronds are divided into numerous leaflets, giving them a delicate and feathery appearance. |
| Flowers | Does not flower indoors. Tree ferns reproduce via spores, not flowers. |
Purple Fountain Grass
| Scientific Name | Pennisetum setaceum 'Rubrum' |
|---|---|
| Family | Poaceae |
| Native To | Hybrid cultivar; species native to Africa, Southwest Asia |
| Also Known As | Purple Fountain Grass, Red Fountain Grass |
| Leaves | The leaves are long, narrow, and arching, with a deep burgundy-purple color. They have a fine texture and create a graceful, flowing appearance. |
| Flowers | It produces bottlebrush-like flower plumes that are initially a deep burgundy-purple, fading to a tan color as they mature. Flowering typically occurs in summer and fall. It is unlikely to flower indoors. |
📏 Size & Growth — Plant Comparison
Australian Tree Fern
Purple Fountain Grass
🌱 Propagation — Comparing Plant Growth
Australian Tree Fern
Methods: Spores, Division (of pups that grow at the base of the trunk)
Difficulty: Difficult
Tips: Spore propagation is very slow and requires sterile conditions. Division is more practical but requires careful handling to avoid damaging the parent plant.
Purple Fountain Grass
Methods: Seed, Division
Difficulty: Moderate
Tips: Divide clumps in spring or early summer. Sow seeds indoors 6-8 weeks before the last frost.
✨ Benefits & Features — Comparing Plant Value
Australian Tree Fern
The Australian Tree Fern's fast growth rate and large size distinguish it from other ferns. Its trunk, covered in brown scales, adds a unique texture and visual appeal. It's also relatively adaptable to different soil types.
- ✓ Creates a lush, tropical atmosphere
- ✓ Adds architectural interest to gardens
- ✓ Provides a sense of tranquility
- ✓ Can improve indoor air quality slightly by increasing humidity
- ✓ Offers a connection to nature
- 🐾 Pet Safe
Purple Fountain Grass
Its deep purple foliage and graceful, arching habit make it a standout in any garden. The bottlebrush-like flower plumes add further visual interest and movement.
- ✓ Adds visual interest and texture to the garden
- ✓ Attracts birds
- ✓ Drought tolerant
- ✓ Deer resistant
- ✓ Provides movement in the landscape
- 🐾 Pet Safe
📅 Maintenance Schedule — Plant Care Comparison
Australian Tree Fern
Purple Fountain Grass
🌞 Light Requirements
Australian Tree Fern
Bright, indirect light to partial shade. Avoid direct sunlight, especially during the hottest part of the day.
Low light tolerant: ❌ No
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
💧 Watering Needs
Australian Tree Fern
Water frequently to keep the soil consistently moist but not waterlogged. Allow the top inch of soil to slightly dry out before watering again. Overwatering can lead to root rot, while underwatering will cause the fronds to dry and brown. Ensure good drainage.
Purple Fountain Grass
Water deeply when the top inch of soil feels dry to the touch. Avoid overwatering, which can lead to root rot. Signs of underwatering include drooping or browning leaves. Signs of overwatering include yellowing leaves and soggy soil.
🌡️ Temperature & Humidity
Australian Tree Fern
Temperature: 18-24°C
Humidity: 60-80%
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
🤔 Which Plant Is Right For You?
Australian Tree Fern
Cyathea cooperiExperienced plant enthusiasts who can provide the high humidity and bright, indirect light required for this fern to thrive.
✅ Choose This Plant If...
- You want a dramatic, tropical statement plant for a large, bright space.
- You can provide consistently high humidity.
- You are experienced with fern care.
- You live in a mild climate where it can be grown outdoors year-round.
- You have a greenhouse or conservatory.
❌ Skip This Plant If...
- You have limited space.
- You cannot provide high humidity.
- You are a beginner plant owner.
Purple Fountain Grass
Pennisetum setaceum 'Rubrum'Gardeners looking for a dramatic ornamental grass to add color and texture to their landscape.
✅ Choose This Plant If...
- You want a striking focal point in your garden.
- You need a drought-tolerant plant for a sunny location.
- You desire a plant with beautiful purple foliage and plumes.
- You want to attract birds to your garden.
- You need a deer-resistant plant.
❌ Skip This Plant If...
- You live in a cold climate and don't want to treat it as an annual.
- You don't have a sunny location.
- You are looking for a low-maintenance indoor plant.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Australian Tree Fern has fast growth, while Purple Fountain Grass grows moderate.
💡 Pro Tips For Comparing These Plants
Australian Tree Fern Care Tips
Australian Tree Ferns are challenging to grow indoors due to their high humidity and light requirements. They need consistent moisture and are prone to drying out in typical indoor environments. Maintaining adequate humidity is crucial for their survival. They are best suited for outdoor environments or greenhouses.
- Mist the fronds regularly to increase humidity.
- Use rainwater or distilled water to avoid mineral buildup on the fronds.
- Provide good air circulation to prevent fungal diseases.
- Protect from strong winds, which can damage the fronds.
- Fertilize regularly during the growing season with a balanced liquid fertilizer.
Purple Fountain Grass Care Tips
Purple Fountain Grass is primarily an outdoor plant and will struggle indoors due to its high light requirements. It needs full sun and well-draining soil. While it can be grown in containers, it requires regular watering and fertilization. Overwintering indoors is possible in colder climates, but the plant may not thrive.
- Plant in well-draining soil in a sunny location.
- Water deeply but infrequently, allowing the soil to dry out between waterings.
- Fertilize in spring with a balanced slow-release fertilizer.
- Cut back foliage in late fall or early spring.
- Protect from frost in colder climates.
⚠️ Common Problems & Solutions — Plant Care Comparison
Australian Tree Fern
Purple Fountain Grass
❓ Frequently Asked Questions — Comparing These Plants
Australian Tree Fern
What are the light requirements for Australian Tree Fern?
Australian Tree Ferns require bright, indirect light to thrive. Direct sunlight can scorch their delicate fronds, causing them to turn brown and crispy. An east-facing window is often ideal, providing gentle morning light. A north-facing window can also work, especially if supplemented with artificial light. If you place your fern near a south or west-facing window, use a sheer curtain to filter the light.
How do I care for Australian Tree Fern?
The Australian Tree Fern thrives in consistently moist conditions and high humidity. Water thoroughly when the top inch of the soil feels slightly dry. Avoid letting the soil dry out completely, as this can lead to browning fronds. Provide bright, indirect light; direct sunlight can scorch the fronds. Maintain humidity levels above 60% by misting regularly, using a humidifier, or placing the pot on a pebble tray filled with water.
How do I propagate Australian Tree Fern?
Australian Tree Ferns can be propagated by division or spores, though spore propagation is more challenging. For division, carefully separate the trunk into sections, ensuring each section has roots. Plant each section in its own pot with well-draining soil. Keep the soil consistently moist and provide high humidity.
Purple Fountain Grass
What are the light requirements for Purple Fountain Grass?
Purple Fountain Grass requires at least 6-8 hours of direct sunlight per day to thrive and develop its characteristic vibrant purple foliage and abundant flower plumes. Insufficient sunlight can lead to leggy growth, faded color, and reduced flowering. When planting, choose a location that receives full sun throughout the day. If growing in containers, rotate the plant regularly to ensure even sun exposure on all sides. In hotter climates, some afternoon shade may be beneficial to prevent scorching, but avoid placing it in deep shade, which will hinder its growth. Supplemental lighting may be necessary if grown indoors during winter months.
How do I care for Purple Fountain Grass?
Purple Fountain Grass thrives in full sun and well-draining soil. Water thoroughly when the top inch of soil feels dry, but avoid overwatering, which can lead to root rot. Fertilize monthly during the growing season (spring and summer) with a balanced fertilizer to promote healthy growth and vibrant blooms. Prune away dead or damaged foliage in late winter or early spring before new growth emerges. In colder climates, treat it as an annual or bring it indoors during the winter. Provide adequate air circulation to prevent fungal diseases. Regularly inspect for pests like aphids or spider mites, and treat accordingly. Avoid planting in overly compacted or poorly draining soil. Mulching around the base can help retain moisture and suppress weeds. Protect from strong winds.
How do I propagate Purple Fountain Grass?
Purple Fountain Grass can be propagated by division. In early spring, carefully dig up the plant and divide the root ball into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions in well-draining soil and water thoroughly. Keep the soil consistently moist until the new plants are established. Division is the most reliable method. Seed propagation is possible but can be inconsistent in producing plants true to the ‘Rubrum’ cultivar. Stem cuttings are not typically used for propagating this grass. Keikis are not applicable as this plant doesn’t produce them. Ensure good air circulation to prevent fungal diseases after dividing.
Last updated: May 4, 2026 — Plant care data reviewed and verified by our editorial team.