Perennial Flax vs Purple Fountain Grass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Perennial Flax
Linum perenne
Perennial Flax (Linum perenne) is a herbaceous perennial known for its delicate, airy appearance and profuse display of sky-blue flowers. It typically grows to a height of 30-60 cm. The plant features slender stems and narrow, lance-shaped leaves. While primarily an outdoor plant, it is grown for its ornamental value in gardens and meadows, attracting pollinators. The flowers are short-lived, opening in the morning and closing by afternoon, but the plant produces a continuous succession of blooms throughout the flowering season. It is not naturally an indoor plant.
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 | Perennial Flax | Purple Fountain Grass |
|---|---|---|
| Light | Full sun | Full sun (at least 6 hours of direct sunlight per day) |
| Watering | Every 7-10 days, depending on weather and soil drainage | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 30-50% | 20-50% |
| Temperature | 15-24°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | N/A (Outdoor plant, not suitable for indoor growing) | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining, sandy or loamy soil | Well-draining soil, such as a sandy loam or a potting mix amended with perlite |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 5 minutes weekly | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Perennial Flax
| Scientific Name | Linum perenne |
|---|---|
| Family | Linaceae |
| Native To | Europe, North Africa, Asia |
| Also Known As | Perennial Flax, Blue Flax, Flax |
| Leaves | Narrow, lance-shaped leaves, typically blue-green in color, arranged alternately along the stems. |
| Flowers | Flowers are typically sky-blue, about 2.5 cm in diameter, with five petals. They open in the morning and close by afternoon. Rarely flowers indoors. |
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
Perennial Flax
Purple Fountain Grass
🌱 Propagation — Comparing Plant Growth
Perennial Flax
Methods: Seed, Division
Difficulty: Easy
Tips: Sow seeds in spring or fall. Divide established plants in spring or fall. Ensure good drainage for successful propagation.
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
Perennial Flax
Perennial Flax is known for its delicate, blue flowers that open in the morning and close by afternoon. It is a relatively low-maintenance perennial that attracts pollinators and is drought-tolerant once established.
- ✓ Attracts pollinators like bees and butterflies.
- ✓ Adds a delicate, airy texture to the garden.
- ✓ Provides a long season of blue flowers.
- ✓ Drought-tolerant once established, reducing water needs.
- ✓ Relatively low-maintenance, freeing up gardening time.
- ⚠️ Toxic to pets
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
Perennial Flax
Purple Fountain Grass
🌞 Light Requirements
Perennial Flax
Full sun
Low light tolerant: ❌ No
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
💧 Watering Needs
Perennial Flax
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Ensure good drainage. Signs of underwatering include wilting and yellowing leaves. Overwatering can cause root rot and fungal diseases.
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
Perennial Flax
Temperature: 15-24°C
Humidity: 30-50%
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
🤔 Which Plant Is Right For You?
Perennial Flax
Linum perenneGardeners looking for a low-maintenance, flowering perennial for sunny locations.
✅ Choose This Plant If...
- You want a low-maintenance perennial for a sunny garden.
- You want to attract pollinators to your garden.
- You appreciate delicate, blue flowers.
- You have well-draining soil.
- You live in a climate with mild winters.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You don't have a sunny outdoor space.
- You are looking for an easy indoor plant.
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
Perennial Flax needs full sun, while Purple Fountain Grass prefers full sun (at least 6 hours of direct sunlight per day).
Perennial Flax has moderate growth, while Purple Fountain Grass grows moderate.
💡 Pro Tips For Comparing These Plants
Perennial Flax Care Tips
Perennial Flax is primarily an outdoor plant and is challenging to grow indoors due to its high light requirements. It needs full sun and well-draining soil. Indoor attempts often result in leggy growth and poor flowering. It is toxic to pets.
- Ensure well-draining soil to prevent root rot.
- Provide full sun for optimal flowering.
- Deadhead spent flowers regularly to encourage more blooms.
- Apply a balanced fertilizer in spring.
- Protect from excessive moisture in winter.
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
Perennial Flax
Purple Fountain Grass
❓ Frequently Asked Questions — Comparing These Plants
Perennial Flax
What are the light requirements for Perennial Flax?
Perennial Flax requires a minimum of six hours of direct sunlight per day to thrive and produce abundant blooms. A south-facing location is ideal, but east or west-facing exposures can also work if they provide sufficient sunlight. Insufficient light can lead to leggy growth, reduced flowering, and pale foliage. If growing indoors, place the plant near a sunny window or supplement with artificial grow lights. Rotate the plant regularly to ensure even light exposure on all sides. When transplanting, choose a location that receives full sun throughout the day. Be mindful of shadows cast by trees or buildings, especially during the shorter days of winter.
How do I care for Perennial Flax?
Perennial Flax thrives in full sun and well-drained soil. Water deeply but infrequently, allowing the soil to dry out between waterings. Amend heavy clay soils with compost or other organic matter to improve drainage. Fertilize lightly in spring with a balanced fertilizer to encourage blooming. Deadhead spent flowers to promote continued flowering. Cut back the plant after blooming to maintain its shape and encourage bushier growth. Provide support if necessary, as the stems can become leggy. Protect from excessive winter moisture in colder climates. Mulch around the base of the plant to retain moisture and suppress weeds. Monitor for pests and diseases, and treat promptly if necessary. Divide established plants every few years to rejuvenate them.
How do I propagate Perennial Flax?
Perennial Flax can be propagated by seed, division, or stem cuttings.
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: April 19, 2026 — Plant care data reviewed and verified by our editorial team.