Kentucky Bluegrass vs Purple Fountain Grass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Kentucky Bluegrass
Poa pratensis
Kentucky Bluegrass is a perennial cool-season grass known for its fine texture, rich blue-green color, and ability to form a dense, attractive turf. It spreads through rhizomes, creating a thick mat. It's primarily an outdoor plant, valued for lawns, pastures, and sports fields. People grow it for its aesthetic appeal, durability, and ability to withstand moderate foot traffic. It is not suitable as an indoor plant due to its high light and space requirements.
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 | Kentucky Bluegrass | Purple Fountain Grass |
|---|---|---|
| Light | Full sun to partial shade (minimum 6 hours of direct sunlight) | Full sun (at least 6 hours of direct sunlight per day) |
| Watering | 1-2 times per week, depending on weather and soil conditions | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 40-60% | 20-50% |
| Temperature | 15-24°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate To Fast; Aggressive Spreader | Moderate |
| Max Height | Not applicable indoors; outdoors: 15-60 cm | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-drained soil with a pH between 6.0 and 7.0 | Well-draining soil, such as a sandy loam or a potting mix amended with perlite |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30-60 minutes weekly (mowing, watering, weeding) | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Kentucky Bluegrass
| Scientific Name | Poa pratensis |
|---|---|
| Family | Poaceae |
| Native To | Eurasia, but widely naturalized in North America |
| Also Known As | Kentucky Bluegrass, Smooth Meadow-grass |
| Leaves | The leaves are narrow, linear, and typically 2-15 cm long and 2-4 mm wide. They are smooth and have a boat-shaped tip. The color is typically a rich blue-green. |
| Flowers | It rarely flowers indoors. Outdoors, it produces panicles of small, greenish flowers in the spring. |
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
Kentucky Bluegrass
Purple Fountain Grass
🌱 Propagation — Comparing Plant Growth
Kentucky Bluegrass
Methods: Seed, Sod, Division
Difficulty: Easy
Tips: For seed propagation, sow seeds in spring or fall. For division, separate rhizomes and replant. Ensure good soil contact and consistent moisture.
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
Kentucky Bluegrass
Kentucky Bluegrass is known for its rhizomatous growth, which allows it to spread and self-repair. Its fine texture and blue-green color make it a popular choice for lawns.
- ✓ Provides a visually appealing lawn.
- ✓ Offers a durable surface for outdoor activities.
- ✓ Helps prevent soil erosion.
- ✓ Can increase property value.
- ✓ Provides a cooling effect in summer.
- ⚠️ 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
Kentucky Bluegrass
Purple Fountain Grass
🌞 Light Requirements
Kentucky Bluegrass
Full sun to partial shade (minimum 6 hours of direct sunlight)
Low light tolerant: ❌ No
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
💧 Watering Needs
Kentucky Bluegrass
Water deeply but infrequently, allowing the soil to dry slightly between waterings. Overwatering can lead to fungal diseases. Signs of underwatering include wilting and browning; overwatering includes yellowing and potential root rot.
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
Kentucky Bluegrass
Temperature: 15-24°C
Humidity: 40-60%
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
🤔 Which Plant Is Right For You?
Kentucky Bluegrass
Poa pratensisHomeowners seeking a durable and attractive lawn in temperate climates.
✅ Choose This Plant If...
- You want a durable lawn that can withstand moderate foot traffic.
- You appreciate the aesthetic appeal of a dense, blue-green turf.
- You live in a temperate climate with cool summers and cold winters.
- You are willing to commit to regular mowing, watering, and fertilization.
- You need a lawn that recovers well from damage due to its rhizomatous growth.
❌ Skip This Plant If...
- You are looking for an indoor plant.
- You have pets that may ingest the grass.
- You live in a very hot or dry climate.
- You are not willing to commit to regular lawn maintenance.
- You prefer a low-maintenance ground cover option.
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
Kentucky Bluegrass needs full sun to partial shade (minimum 6 hours of direct sunlight), while Purple Fountain Grass prefers full sun (at least 6 hours of direct sunlight per day).
Kentucky Bluegrass has moderate to fast; aggressive spreader growth, while Purple Fountain Grass grows moderate.
💡 Pro Tips For Comparing These Plants
Kentucky Bluegrass Care Tips
Kentucky Bluegrass is an outdoor plant requiring full sun, well-drained soil, and regular watering and fertilization. It is extremely challenging to grow indoors due to its high light needs and spreading growth habit. It is also toxic to pets.
- Aerate the soil annually to improve drainage and air circulation.
- Overseed bare patches in the spring or fall to maintain a dense turf.
- Mow regularly at the correct height to promote healthy growth.
- Fertilize according to soil test recommendations.
- Water deeply but infrequently to encourage deep root growth.
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
Kentucky Bluegrass
Purple Fountain Grass
❓ Frequently Asked Questions — Comparing These Plants
Kentucky Bluegrass
What are the light requirements for Kentucky Bluegrass?
Kentucky Bluegrass thrives in full sun, requiring at least 6 to 8 hours of direct sunlight daily to promote healthy growth and abundant flowering. Insufficient sunlight can lead to weak, leggy growth and reduced bloom production.
How do I care for Kentucky Bluegrass?
Kentucky Bluegrass, as a flowering plant, requires specific care to thrive. Plant in well-draining soil with a pH between 6.0 and 7.0. Ensure it receives at least 6-8 hours of direct sunlight daily for optimal flowering. Water deeply but infrequently, allowing the soil to dry slightly between waterings.
How do I propagate Kentucky Bluegrass?
Kentucky Bluegrass can be propagated through division, stem cuttings, and keiki (though keiki are rare).
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 20, 2026 — Plant care data reviewed and verified by our editorial team.