Lima Bean vs Purple Fountain Grass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Lima Bean
Phaseolus lunatus
The lima bean (Phaseolus lunatus) is a legume grown for its edible seeds or beans. It is a herbaceous annual vine, typically grown outdoors in gardens or fields. It features trifoliate leaves and produces pods containing the characteristic lima beans. While it can be technically grown indoors, it requires very specific and intense lighting conditions to thrive and produce beans. People grow lima beans primarily for food, as the beans are a good source of protein and fiber. It is not typically grown as an ornamental 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 | Lima Bean | Purple Fountain Grass |
|---|---|---|
| Light | Full sun (at least 6-8 hours of direct sunlight daily) | Full sun (at least 6 hours of direct sunlight per day) |
| Watering | 2-3 times per week outdoors, depending on weather conditions | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 40-60% | 20-50% |
| Temperature | 20-27°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | Outdoors: 2-4 meters (vine length). Indoors: Highly variable and difficult to achieve significant growth. | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining loamy soil | Well-draining soil, such as a sandy loam or a potting mix amended with perlite |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly outdoors during growing season. | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Lima Bean
| Scientific Name | Phaseolus lunatus |
|---|---|
| Family | Fabaceae |
| Native To | South America (Andes) and Central America |
| Also Known As | Lima bean, Butter bean, Sieva bean, Madagascar bean |
| Leaves | Trifoliate leaves, meaning each leaf is composed of three leaflets. The leaflets are typically oval-shaped and green. |
| Flowers | Small, pea-like flowers that are typically white or pale yellow. Flowering occurs outdoors during the growing season, but is unlikely 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
Lima Bean
Purple Fountain Grass
🌱 Propagation — Comparing Plant Growth
Lima Bean
Methods: Seed
Difficulty: Easy
Tips: Soak seeds in water for 24 hours before planting. Plant in well-draining soil and keep moist until germination.
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
Lima Bean
Lima beans are known for their distinctive flavor and texture. They are also a good source of nutrients and can help improve soil quality.
- ✓ Provides fresh, homegrown food.
- ✓ Improves soil quality through nitrogen fixation.
- ✓ Adds vertical interest to the garden.
- ✓ Offers a sense of accomplishment from growing your own food.
- ✓ Provides a healthy source of protein and fiber.
- ⚠️ 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
Lima Bean
Purple Fountain Grass
🌞 Light Requirements
Lima Bean
Full sun (at least 6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
💧 Watering Needs
Lima Bean
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. 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
Lima Bean
Temperature: 20-27°C
Humidity: 40-60%
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
🤔 Which Plant Is Right For You?
Lima Bean
Phaseolus lunatusGardeners with outdoor space who want to grow their own beans.
✅ Choose This Plant If...
- You have a sunny outdoor garden and want to grow your own food.
- You enjoy the taste of fresh lima beans.
- You want a plant that can help improve soil quality through nitrogen fixation.
- You are looking for a climbing vine to add vertical interest to your garden.
- You are experienced with growing vegetables and want a new challenge.
❌ Skip This Plant If...
- You have limited outdoor space.
- You have pets that might ingest the plant.
- You are looking for a low-maintenance indoor plant.
- You don't have access to adequate sunlight.
- You are a beginner gardener.
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
Lima Bean needs full sun (at least 6-8 hours of direct sunlight daily), while Purple Fountain Grass prefers full sun (at least 6 hours of direct sunlight per day).
Lima Bean has fast growth, while Purple Fountain Grass grows moderate.
💡 Pro Tips For Comparing These Plants
Lima Bean Care Tips
Lima beans are primarily outdoor plants. Growing them indoors is challenging due to the high light requirements and space needed for the vine. They are also toxic to pets. Indoor cultivation requires supplemental lighting and careful monitoring of soil moisture and humidity. Bean production indoors is unlikely.
- Soak seeds before planting to improve germination rates.
- Provide a trellis or other support for the vines to climb.
- Water deeply and regularly, especially during hot weather.
- Fertilize monthly during the growing season.
- Monitor for pests and diseases and treat promptly.
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
Lima Bean
Purple Fountain Grass
❓ Frequently Asked Questions — Comparing These Plants
Lima Bean
What are the light requirements for Lima Bean?
Lima beans require at least 6-8 hours of direct sunlight daily to thrive and produce abundant flowers and beans. A south-facing location is ideal, providing maximum sun exposure. If grown indoors, place the plants near a sunny window or supplement with grow lights. Insufficient light can result in leggy growth, reduced flowering, and poor bean production. Rotate the plants regularly to ensure even light exposure on all sides. Monitor the foliage for signs of sunburn, such as bleached or brown spots, and adjust placement accordingly. During periods of intense heat, provide some afternoon shade to prevent stress. The intensity and duration of light significantly impact the plant’s overall health and productivity. Consistent light exposure is crucial for optimal growth and flowering.
How do I care for Lima Bean?
Lima beans thrive in warm climates with plenty of sunshine. Plant them in well-draining soil rich in organic matter. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Provide a trellis or support structure for the vines to climb. Fertilize every few weeks with a balanced fertilizer, switching to a bloom-boosting formula once flowering begins. Monitor for pests such as aphids and bean beetles, and address infestations promptly with insecticidal soap or neem oil. Regularly prune the vines to encourage bushier growth and more abundant flowering. Harvest the beans when they are young and tender, if desired. Ensure adequate air circulation to prevent fungal diseases. Mulch around the base of the plants to retain moisture and suppress weeds. Protect young plants from frost. Provide consistent care throughout the growing season for optimal flowering and bean production. Rotate crops yearly to prevent soilborne diseases.
How do I propagate Lima Bean?
Lima beans are typically propagated by seed. However, stem cuttings can be used, though success rates are lower.
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 14, 2026 — Plant care data reviewed and verified by our editorial team.