Purple Fountain Grass vs Rain Lily Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
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.
Rain Lily
Zephyranthes spp.
Rain Lilies are small, bulbous perennials known for their delightful, trumpet-shaped flowers that often appear after rainfall, hence the name. They typically grow to a height of 15-30 cm. The foliage consists of slender, grass-like leaves. While they can be grown indoors, they thrive outdoors in well-draining soil and plenty of sunlight. People grow them for their charming blooms, ease of care (outdoors), and ability to naturalize in suitable climates. They are popular in rock gardens, borders, and containers.
Quick Plant Comparison
| Feature | Purple Fountain Grass | Rain Lily |
|---|---|---|
| Light | Full sun (at least 6 hours of direct sunlight per day) | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering. |
| Watering | Every 7-10 days, depending on weather and soil drainage | Every 7-10 days during the growing season, less frequently during dormancy. |
| Humidity | 20-50% | 40-60% |
| Temperature | 18-30°C | 18-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters | 15-30 cm |
| Pet Safety | ✅ Safe | ❌ Toxic To Pets |
| Soil | Well-draining soil, such as a sandy loam or a potting mix amended with perlite | Well-draining soil mix, such as a sandy loam or a mix of potting soil, perlite, and sand. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 15 minutes weekly | 5 minutes weekly (outdoors) |
🔬 Botanical Information — Comparing These Plants
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. |
Rain Lily
| Scientific Name | Zephyranthes spp. |
|---|---|
| Family | Amaryllidaceae |
| Native To | Americas, from the United States to Argentina |
| Also Known As | Rain Lily, Fairy Lily, Zephyr Lily |
| Leaves | The leaves are slender, linear, and grass-like, typically 15-30 cm long and 0.5-1 cm wide. They are usually a medium green color and have a smooth texture. |
| Flowers | Rain Lilies can flower indoors, but it is less common and less prolific than outdoors. The flowers are trumpet-shaped, with six petals, and come in various colors, including white, pink, yellow, and red. They typically last for a few days. |
📏 Size & Growth — Plant Comparison
Purple Fountain Grass
Rain Lily
🌱 Propagation — Comparing Plant Growth
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.
Rain Lily
Methods: Division, Seed
Difficulty: Easy
Tips: Divide bulbs after flowering or collect and sow seeds in spring. For division, gently separate offsets from the main bulb and replant them in well-draining soil. For seeds, sow them in a seed-starting mix and keep them moist until germination.
✨ Benefits & Features — Comparing Plant Value
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
Rain Lily
The most unique characteristic is their tendency to bloom after rainfall, a phenomenon that is triggered by the sudden increase in moisture. This makes them a delightful surprise in the garden. The flowers are also relatively short-lived, adding to their ephemeral charm.
- ✓ Attracts pollinators to the garden.
- ✓ Adds a splash of color to the landscape.
- ✓ Low maintenance once established.
- ✓ Can be grown in containers or in the ground.
- ✓ Provides a natural, informal aesthetic.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Purple Fountain Grass
Rain Lily
🌞 Light Requirements
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
Rain Lily
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.
Low light tolerant: ❌ No
💧 Watering Needs
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.
Rain Lily
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to bulb rot. Reduce watering during dormancy. Signs of overwatering include yellowing leaves and a mushy bulb. Underwatering results in dry, brittle leaves and stunted growth.
🌡️ Temperature & Humidity
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
Rain Lily
Temperature: 18-27°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
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.
Rain Lily
Zephyranthes spp.Gardeners in warm climates looking for low-maintenance, flowering plants for borders, rock gardens, or containers.
✅ Choose This Plant If...
- You live in a warm climate with mild winters.
- You want a low-maintenance plant for your garden.
- You enjoy flowers that bloom after rainfall.
- You have a sunny garden or rock garden.
- You want to attract pollinators to your garden.
❌ Skip This Plant If...
- You live in a cold climate with harsh winters.
- You have pets that might ingest the plant.
- You don't have a sunny location.
- You want a plant that flowers reliably indoors.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.
💡 Pro Tips For Comparing These Plants
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.
Rain Lily Care Tips
Rain Lilies are best suited for outdoor cultivation. Indoor growing is challenging due to high light requirements. They need well-draining soil, regular watering during the growing season, and protection from frost. Indoor plants rarely flower as prolifically as outdoor ones.
- Plant bulbs in well-draining soil to prevent rot.
- Provide full sun for optimal flowering.
- Water deeply but infrequently, allowing the soil to dry out between waterings.
- Fertilize during the growing season to encourage blooms.
- Protect from frost in colder climates.
⚠️ Common Problems & Solutions — Plant Care Comparison
Purple Fountain Grass
Rain Lily
❓ Frequently Asked Questions — Comparing These Plants
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.
Rain Lily
What are the light requirements for Rain Lily?
Rain Lilies thrive in bright, indirect light. Indoors, place them near an east- or west-facing window where they can receive several hours of sunlight daily. If you notice the leaves becoming pale or leggy, it indicates insufficient light. Conversely, scorching can occur if they are exposed to intense, direct sunlight, especially during the hottest part of the day. Rotate the pot regularly to ensure even light exposure on all sides of the plant. Supplement with grow lights if natural light is limited, especially during winter months.
How do I care for Rain Lily?
Rain Lilies are relatively easy to care for, requiring well-draining soil and bright, indirect light. Water thoroughly when the top inch of soil feels dry, and allow the soil to dry out slightly between waterings. Fertilize with a balanced liquid fertilizer during the growing season (spring and summer) to encourage blooming. Repot every 2-3 years or when the bulbs become overcrowded. Protect from frost in colder climates by bringing potted plants indoors or mulching garden beds. Deadhead spent flowers to promote further blooming. Provide adequate drainage to prevent root rot, and ensure good air circulation. Avoid overwatering, especially during dormancy.
How do I propagate Rain Lily?
Rain Lilies can be easily propagated by division. When repotting, gently separate the bulbs and plant them in individual pots. Offsets, or small bulbs that form around the base of the main bulb, can also be removed and planted. Stem cuttings are not applicable for Rain Lilies as they grow from bulbs. Keikis are not applicable for Rain Lilies. Ensure each division has healthy roots. Plant in well-draining soil and water thoroughly. Keep the soil consistently moist until new growth appears.
Last updated: April 25, 2026 — Plant care data reviewed and verified by our editorial team.