Mung 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.
Mung Bean
Vigna radiata
The mung bean is an annual vine-like legume grown primarily for its edible seeds and sprouts. It is characterized by its trifoliate leaves and small, yellow flowers. The plant is typically grown outdoors in warm climates and reaches a height of about 30-120 cm. While it can be grown indoors, it requires specific conditions to thrive and is more commonly cultivated for sprouting purposes rather than full plant growth. People grow mung beans for food, as they are a nutritious source of protein and fiber.
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 | Mung Bean | Purple Fountain Grass |
|---|---|---|
| Light | Full sun to partial shade outdoors; Very bright, direct light if attempting to grow indoors. | Full sun (at least 6 hours of direct sunlight per day) |
| Watering | Every 2-3 days outdoors during the growing season; Every 5-7 days indoors, depending on light and humidity. | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 40-60% | 20-50% |
| Temperature | 20-30°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | 30-120 cm outdoors; 30-60 cm indoors (if successfully grown) | Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters |
| Pet Safety | ✅ Safe | ✅ 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 | 15-30 minutes weekly | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Mung Bean
| Scientific Name | Vigna radiata |
|---|---|
| Family | Fabaceae |
| Native To | Indian subcontinent |
| Also Known As | Mung bean, green gram, golden gram |
| Leaves | The leaves of the mung bean are trifoliate, meaning they consist of three leaflets. Each leaflet is ovate to lanceolate in shape, with a smooth texture and a vibrant green color. The leaves are arranged alternately along the stem. |
| Flowers | Mung beans produce small, yellow, papilionaceous flowers that are typical of legumes. The flowers are self-pollinating and give rise to slender pods containing the mung bean seeds. Flowering is rare 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
Mung Bean
Purple Fountain Grass
🌱 Propagation — Comparing Plant Growth
Mung Bean
Methods: Seed
Difficulty: Easy
Tips: Soak seeds in water for 24 hours before planting. Sow seeds directly into well-draining soil. Keep soil consistently 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
Mung Bean
Mung beans are unique for their ability to fix nitrogen in the soil, making them a valuable cover crop. They are also known for their fast germination and sprouting capabilities. The entire plant is edible, including the seeds, sprouts, and young pods.
- ✓ Provides a nutritious food source.
- ✓ Enriches soil with nitrogen.
- ✓ Fast-growing and relatively easy to sprout.
- ✓ Adds visual interest to a garden.
- ✓ Supports sustainable agriculture.
- 🐾 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
Mung Bean
Purple Fountain Grass
🌞 Light Requirements
Mung Bean
Full sun to partial shade outdoors; Very bright, direct light if attempting to grow indoors.
Low light tolerant: ❌ No
Purple Fountain Grass
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
💧 Watering Needs
Mung Bean
Water regularly to keep the soil consistently moist, but not waterlogged, especially during the growing season. Reduce watering during cooler months. Overwatering can lead to root rot, indicated by yellowing leaves and a musty smell. Underwatering will cause leaves to wilt and dry out.
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
Mung Bean
Temperature: 20-30°C
Humidity: 40-60%
Purple Fountain Grass
Temperature: 18-30°C
Humidity: 20-50%
🤔 Which Plant Is Right For You?
Mung Bean
Vigna radiataGardeners in warm climates looking for a nutritious and fast-growing crop.
✅ Choose This Plant If...
- You want a fast-growing crop for sprouts or seeds.
- You live in a warm climate with plenty of sunshine.
- You are interested in nitrogen-fixing plants for soil improvement.
- You enjoy growing your own food.
- You have experience with growing legumes.
❌ Skip This Plant If...
- You have limited indoor light.
- You are looking for a low-maintenance indoor plant.
- You live in a cold climate with short growing seasons.
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
Mung Bean has fast growth, while Purple Fountain Grass grows moderate.
💡 Pro Tips For Comparing These Plants
Mung Bean Care Tips
Mung beans are primarily an outdoor crop. Growing them indoors requires providing intense light, consistent moisture, and adequate ventilation. It is challenging to replicate outdoor growing conditions indoors. Most indoor cultivation focuses on sprouting seeds for consumption rather than growing a full plant.
- Provide a trellis or support for the vines to climb.
- Ensure good drainage to prevent root rot.
- Monitor for pests and diseases regularly.
- Harvest seeds when pods are dry and brown.
- Sprout seeds in a jar with regular rinsing.
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
Mung Bean
Purple Fountain Grass
❓ Frequently Asked Questions — Comparing These Plants
Mung Bean
What are the light requirements for Mung Bean?
Mung bean plants require ample sunlight to flourish and produce blooms. Aim for at least 6 hours of direct sunlight per day. A south-facing window is ideal, but east or west-facing windows can also work if supplemented with grow lights. Insufficient light can lead to leggy growth, reduced flowering, and overall weak plant health. Rotate the plant regularly to ensure even light exposure on all sides. If using grow lights, position them 12-18 inches above the plant and provide 14-16 hours of light per day. Observe the plant closely for signs of light stress, such as scorched leaves or excessive stretching, and adjust accordingly.
How do I care for Mung Bean?
Mung bean plants thrive with consistent care. Provide them with at least 6 hours of direct sunlight daily, ideally in a south-facing window. Water when the top inch of soil feels dry to the touch, ensuring good drainage to prevent root rot. Use a well-draining potting mix rich in organic matter. Fertilize every 2-3 weeks during the growing season (spring and summer) with a balanced liquid fertilizer, diluted to half strength. Maintain a temperature between 65-80°F (18-27°C). Prune any yellowing or dead leaves to encourage new growth. Mist occasionally to increase humidity, especially in dry environments. Provide support like a trellis or stakes as the plant grows to support the vines. Monitor regularly for pests and diseases, addressing any issues promptly.
How do I propagate Mung Bean?
Mung bean plants are most commonly propagated by seed. However, stem cuttings can also be successful.
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 13, 2026 — Plant care data reviewed and verified by our editorial team.