Fairy Moss vs Lemon Grass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Fairy Moss
Azolla filiculoides
Azolla filiculoides, commonly known as Fairy Moss, is a small, free-floating aquatic fern. It forms a dense mat on the surface of still or slow-moving water. The plant is characterized by its tiny, overlapping leaves, which give it a moss-like appearance. It's typically grown outdoors in ponds, water gardens, or rice paddies. People cultivate it for its nitrogen-fixing abilities (symbiotic relationship with cyanobacteria), ornamental value, and potential use as a green manure or animal feed. It is not naturally an indoor plant and requires very specific conditions to thrive indoors.
Lemon Grass
Cymbopogon citratus
Lemon Grass is a tall, perennial grass characterized by its fragrant, lemon-scented leaves and stalks. It typically grows in dense clumps, reaching heights of up to 1.8 meters (6 feet) outdoors. The plant is primarily cultivated for culinary and medicinal purposes, with its stalks and leaves used to flavor dishes, teas, and herbal remedies. While it can be grown indoors, it requires very bright light and may not thrive as well as it does outdoors. People grow it for its unique flavor and aroma, as well as its potential health benefits.
Quick Plant Comparison
| Feature | Fairy Moss | Lemon Grass |
|---|---|---|
| Light | Full sun to partial shade | Full sun (at least 6-8 hours of direct sunlight daily) |
| Watering | N/A - lives in water | Every 2-3 days during the growing season, less frequently in winter (every 7-10 days) |
| Humidity | 70-90% | 40-60% |
| Temperature | 15-25°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Fast |
| Max Height | Less than 2.5 cm above the water surface. | 0.6-1.2 meters (2-4 feet) indoors, up to 1.8 meters (6 feet) outdoors |
| Pet Safety | ✅ Safe | ❌ Toxic To Pets |
| Soil | N/A - Free-floating, but benefits from nutrient-rich water. | Well-draining, loamy soil. A mix of potting soil, sand, and perlite is suitable. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 15 minutes weekly (for thinning and water quality checks) | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Fairy Moss
| Scientific Name | Azolla filiculoides |
|---|---|
| Family | Salviniaceae |
| Native To | Americas (North and South) |
| Also Known As | Fairy Moss, Mosquito Fern, Water Fern |
| Leaves | Tiny, overlapping leaves, typically 1-2 mm long. They are usually green, but can turn reddish in strong sunlight or under stress. The leaves are arranged in two rows along the stem. |
| Flowers | Rarely flowers. When it does, the reproductive structures are small and inconspicuous, located at the base of the leaves. |
Lemon Grass
| Scientific Name | Cymbopogon citratus |
|---|---|
| Family | Poaceae |
| Native To | Southeast Asia (India, Sri Lanka, Malaysia, Thailand) |
| Also Known As | Lemon Grass, Lemongrass, Oil Grass, Fever Grass, Tanglad |
| Leaves | The leaves of Lemon Grass are long, slender, and blade-like, typically reaching lengths of 30-90 cm (12-35 inches). They are a vibrant green color and have a slightly rough texture. The leaves have a prominent midrib and taper to a sharp point. When crushed, they release a strong lemon scent. |
| Flowers | Lemon Grass rarely flowers indoors. Outdoors, it may produce flower spikes in warm climates, but flowering is infrequent and not the primary reason for cultivation. The flowers are small and inconspicuous. |
📏 Size & Growth — Plant Comparison
Fairy Moss
Lemon Grass
🌱 Propagation — Comparing Plant Growth
Fairy Moss
Methods: Fragmentation (natural division of the plant)
Difficulty: Easy
Tips: Simply allow the plant to divide naturally. Ensure adequate nutrients and light for rapid growth.
Lemon Grass
Methods: Division, Seed
Difficulty: Easy
Tips: Divide mature clumps in spring or summer. Ensure each division has healthy roots and shoots. Plant in well-draining soil and keep moist. Seeds can be sown indoors in early spring.
✨ Benefits & Features — Comparing Plant Value
Fairy Moss
Its symbiotic relationship with nitrogen-fixing cyanobacteria allows it to thrive in nutrient-poor waters. It can rapidly multiply, forming a dense mat on the water surface. Its small, overlapping leaves give it a unique moss-like appearance.
- ✓ Natural nitrogen fixation for aquatic ecosystems.
- ✓ Provides habitat and food for small aquatic organisms.
- ✓ Aesthetically pleasing addition to water gardens.
- ✓ Potential use as a sustainable fertilizer.
- ✓ Can help suppress mosquito larvae by covering the water surface.
- 🐾 Pet Safe
Lemon Grass
Lemon Grass is known for its distinct lemon scent and flavor, which is due to the presence of citronellal and geraniol. It is a fast-growing grass that can reach impressive heights under optimal conditions. Unlike many ornamental grasses, it is primarily grown for its culinary and medicinal uses.
- ✓ Adds a unique flavor to culinary dishes
- ✓ Provides a refreshing aroma
- ✓ May have medicinal properties
- ✓ Acts as a natural insect repellent
- ✓ Enhances the aesthetic appeal of a garden or patio
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Fairy Moss
Lemon Grass
🌞 Light Requirements
Fairy Moss
Full sun to partial shade
Low light tolerant: ❌ No
Lemon Grass
Full sun (at least 6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Fairy Moss
Requires constantly moist conditions. It floats on water, so the surrounding water body needs to be maintained. Avoid letting the water dry out completely.
Lemon Grass
Keep the soil consistently moist, but not waterlogged. Allow the top inch of soil to dry out slightly between waterings. Overwatering can lead to root rot, while underwatering will cause the leaves to dry out and turn brown. Ensure good drainage.
🌡️ Temperature & Humidity
Fairy Moss
Temperature: 15-25°C
Humidity: 70-90%
Lemon Grass
Temperature: 18-30°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Fairy Moss
Azolla filiculoidesExperienced aquatic gardeners looking to add a unique, nitrogen-fixing plant to their outdoor ponds or water features.
✅ Choose This Plant If...
- You have an outdoor pond or water garden and want a natural way to fix nitrogen.
- You are interested in using it as a green manure or animal feed.
- You want a fast-growing plant to quickly cover the water surface.
- You are looking for a unique and visually appealing aquatic plant.
- You are interested in a plant with a symbiotic relationship with nitrogen-fixing bacteria.
❌ Skip This Plant If...
- You do not have an outdoor pond or water garden.
- You are looking for a low-maintenance indoor plant.
- You live in a climate with harsh winters where it may not survive.
- You are concerned about its potential to become invasive in certain environments.
Lemon Grass
Cymbopogon citratusExperienced gardeners who can provide ample sunlight and manage its growth.
✅ Choose This Plant If...
- You want a fragrant herb for cooking and teas
- You have a sunny outdoor space
- You enjoy the challenge of growing plants that require specific conditions
- You want a natural insect repellent
- You are interested in the potential health benefits of Lemon Grass
❌ Skip This Plant If...
- You have pets that may ingest it
- You lack a very sunny location
- You don't want to deal with a plant that spreads via rhizomes
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Fairy Moss needs full sun to partial shade, while Lemon Grass prefers full sun (at least 6-8 hours of direct sunlight daily).
💡 Pro Tips For Comparing These Plants
Fairy Moss Care Tips
Fairy Moss is primarily an outdoor plant. Indoor cultivation is challenging due to the high light and humidity requirements. It needs a dedicated aquatic setup with strong lighting and consistent water quality. It can quickly take over a small container if conditions are ideal.
- Provide adequate sunlight for optimal growth and nitrogen fixation.
- Monitor water quality regularly and perform water changes as needed.
- Thin out the mat periodically to prevent overcrowding.
- Protect from freezing temperatures in winter.
- Introduce beneficial insects to control pests.
Lemon Grass Care Tips
Lemon Grass is primarily an outdoor plant that requires full sun and consistent moisture. Growing it indoors can be challenging due to its high light requirements. It also spreads via rhizomes, so it may outgrow its container quickly. Regular division and repotting are necessary.
- Provide at least 6-8 hours of direct sunlight daily
- Ensure well-draining soil to prevent root rot
- Water deeply when the top inch of soil is dry
- Fertilize regularly during the growing season
- Divide the plant every 1-2 years to control its spread
⚠️ Common Problems & Solutions — Plant Care Comparison
Fairy Moss
Lemon Grass
❓ Frequently Asked Questions — Comparing These Plants
Fairy Moss
What are the light requirements for Fairy Moss?
Fairy Moss requires bright, indirect light to flourish. Insufficient light will result in stunted growth and a loss of vibrant coloration. Place your Fairy Moss near a window that receives filtered sunlight, or use artificial lighting specifically designed for aquatic plants. LED grow lights are an excellent option, providing consistent and controlled light exposure.
How do I care for Fairy Moss?
Fairy Moss thrives in calm, nutrient-rich water. Provide bright, indirect light; direct sunlight can scorch the delicate fronds. Water temperature should be between 65-80°F (18-27°C). Maintain excellent water quality by performing regular water changes, especially if kept in a closed aquarium system.
How do I propagate Fairy Moss?
Fairy Moss is incredibly easy to propagate through division. Simply separate a portion of the existing colony and place it in a new container with suitable water conditions. The separated portion will quickly grow and expand, forming a new colony.
Lemon Grass
What are the light requirements for Lemon Grass?
Lemon Grass requires at least 6 hours of bright, indirect sunlight daily. Direct sunlight can scorch the leaves, so it’s best to place it near an east- or west-facing window where it receives filtered light. If you don’t have enough natural light, you can supplement with a grow light. Rotate the plant regularly to ensure even growth on all sides. Inadequate light can lead to leggy growth and reduced essential oil production, affecting the plant’s fragrance. Avoid placing Lemon Grass in a dark or shaded area.
How do I care for Lemon Grass?
Lemon Grass thrives in bright, indirect sunlight and requires well-draining soil. Water regularly, keeping the soil consistently moist but not waterlogged. During the growing season (spring and summer), fertilize monthly with a balanced liquid fertilizer. Prune regularly to maintain shape and encourage new growth. Lemon Grass prefers warm temperatures and high humidity; consider using a humidifier or placing the plant on a pebble tray filled with water. Repot annually in the spring to provide fresh soil and space for growth. Protect from frost and cold temperatures, as it is not cold-hardy. Monitor for pests such as aphids or spider mites and treat accordingly.
How do I propagate Lemon Grass?
Lemon Grass can be easily propagated through division, stem cuttings, or air layering. For division, carefully separate the plant into smaller clumps, ensuring each clump has healthy roots. For stem cuttings, take a 4-6 inch cutting from a healthy stem, remove the lower leaves, and plant it in moist soil. Keep the soil consistently moist until roots develop. For air layering, make a small cut on a stem, wrap it with moist sphagnum moss, and cover with plastic wrap. Once roots develop, cut the stem below the roots and plant it in soil. Propagation is best done in the spring or summer.
Last updated: April 19, 2026 — Plant care data reviewed and verified by our editorial team.