Herb Robert vs Lemongrass Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Herb Robert
Geranium robertianum
Herb Robert is an annual or biennial plant characterized by its distinctive reddish stems and finely divided, fern-like leaves. It typically grows to a height of 15-45 cm. The plant produces small, pink, five-petaled flowers. It is often found in shaded or semi-shaded areas, such as woodlands, hedgerows, and disturbed ground. While primarily an outdoor plant, it is sometimes grown for its purported medicinal properties and its ability to thrive in difficult conditions. It is considered a weed in many areas due to its prolific seed production and ability to self-seed readily.
Lemongrass
Cymbopogon citratus
Lemongrass is a tall, perennial grass characterized by its fragrant, lemon-scented leaves and stalks. It typically grows in dense clumps, reaching heights of 3-5 feet outdoors. The plant is primarily grown for its culinary and medicinal uses, as well as its aromatic properties. While it can be grown indoors, it requires very bright light and consistent care to thrive. It is more commonly cultivated outdoors in warmer climates.
Quick Plant Comparison
| Feature | Herb Robert | Lemongrass |
|---|---|---|
| Light | Partial shade to full sun | Full sun (6-8 hours of direct sunlight daily) |
| Watering | Every 5-7 days, depending on environmental conditions | Every 3-7 days, depending on environmental conditions and pot size. More frequent watering is needed during hot, sunny periods. |
| Humidity | 30-60% | 40-60% |
| Temperature | 10-24°C | 18-30°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Fast |
| Max Height | 0.15-0.45 m | 1-3 feet (indoors), 3-5 feet (outdoors) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining soil, such as a mix of garden soil, compost, and perlite | Well-draining, loamy soil. A mix of potting soil, perlite, and sand is suitable. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 10 minutes weekly | 15 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Herb Robert
| Scientific Name | Geranium robertianum |
|---|---|
| Family | Geraniaceae |
| Native To | Europe, Asia, North Africa, and North America |
| Also Known As | Herb Robert, Red Robin, Death come quickly, Storksbill, Fox geranium |
| Leaves | The leaves are finely divided and fern-like, with a reddish-green color. They are typically 2-5 cm long and have a slightly hairy texture. |
| Flowers | Herb Robert produces small, pink, five-petaled flowers that are approximately 1 cm in diameter. Flowering occurs primarily in spring and summer, but can continue sporadically throughout the year. |
Lemongrass
| Scientific Name | Cymbopogon citratus |
|---|---|
| Family | Poaceae |
| Native To | Southeast Asia (India, Sri Lanka, Malaysia, Thailand) |
| Also Known As | Lemongrass, Oil Grass, Fever Grass, Citronella Grass |
| Leaves | The leaves are long, slender, and blade-like, typically 1-3 feet long and 0.5-1 inch wide. They are bright green in color and have a rough texture. The leaves emit a strong lemon scent when crushed. |
| Flowers | Lemongrass rarely flowers indoors. Outdoors, it may produce flower spikes with small, inconspicuous flowers under ideal conditions, but flowering is not its primary feature. |
📏 Size & Growth — Plant Comparison
Herb Robert
Lemongrass
🌱 Propagation — Comparing Plant Growth
Herb Robert
Methods: Seed
Difficulty: Easy
Tips: Collect seeds from mature seed pods and sow them directly into the soil in spring or fall. Seeds germinate readily in moist soil.
Lemongrass
Methods: Division, Seed, Rooting stem cuttings in water
Difficulty: Easy
Tips: Divide mature clumps in spring or summer. For stem cuttings, place the cut end in water until roots develop, then plant in soil. Keep soil consistently moist during propagation.
✨ Benefits & Features — Comparing Plant Value
Herb Robert
Herb Robert is known for its distinctive reddish stems and leaves, as well as its ability to thrive in challenging conditions. It also has a strong, musky odor when crushed.
- ✓ Attracts pollinators
- ✓ Provides ground cover
- ✓ Adds visual interest with reddish foliage
- ✓ May have medicinal properties (research thoroughly)
- ✓ Tolerates poor soil conditions
- ⚠️ Toxic to pets
Lemongrass
Lemongrass is distinguished by its strong lemon scent and flavor, which is due to the presence of citronella oil. It is a fast-growing grass that can reach impressive heights in optimal conditions. Its culinary and medicinal uses make it a valuable addition to any garden.
- ✓ Fresh lemongrass for culinary use
- ✓ Natural insect repellent
- ✓ Aromatic fragrance
- ✓ Adds a tropical aesthetic to your garden or home
- ✓ Potential medicinal benefits (consult a healthcare professional)
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Herb Robert
Lemongrass
🌞 Light Requirements
Herb Robert
Partial shade to full sun
Low light tolerant: ❌ No
Lemongrass
Full sun (6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Herb Robert
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting leaves, while overwatering can cause yellowing leaves and a soggy soil.
Lemongrass
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting and browning leaf tips. Signs of overwatering include yellowing leaves and a soggy soil.
🌡️ Temperature & Humidity
Herb Robert
Temperature: 10-24°C
Humidity: 30-60%
Lemongrass
Temperature: 18-30°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Herb Robert
Geranium robertianumGardeners looking for a low-maintenance ground cover in shaded areas, understanding its potential to spread.
✅ Choose This Plant If...
- You want a plant that tolerates shade and poor soil
- You are interested in traditional herbal remedies (with caution and research)
- You want a plant with interesting reddish foliage
- You need a ground cover for a difficult area in your garden
- You are comfortable managing a plant that self-seeds readily.
❌ Skip This Plant If...
- You have pets that might ingest it
- You want a low-maintenance indoor plant
- You are concerned about invasive species or aggressive spread.
Lemongrass
Cymbopogon citratusExperienced gardeners in warm climates who want to grow their own culinary herb and are aware of the plant's toxicity to pets.
✅ Choose This Plant If...
- You want to grow your own fresh lemongrass for cooking and teas.
- You live in a warm climate with plenty of sunlight.
- You are an experienced gardener looking for a rewarding challenge.
- You want a natural insect repellent in your garden.
- You are aware of the plant's toxicity to pets and can keep it out of their reach.
❌ Skip This Plant If...
- You have pets that may ingest the plant.
- You live in a cold climate with limited sunlight.
- You are a beginner gardener looking for an easy-care plant.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Herb Robert needs partial shade to full sun, while Lemongrass prefers full sun (6-8 hours of direct sunlight daily).
💡 Pro Tips For Comparing These Plants
Herb Robert Care Tips
Herb Robert is primarily an outdoor plant and can be challenging to grow indoors due to its need for specific light and temperature conditions. It requires well-draining soil and regular watering, but is prone to fungal diseases if kept too moist. It spreads easily by seed.
- Provide adequate drainage to prevent root rot
- Monitor for pests and diseases regularly
- Deadhead spent flowers to encourage continued blooming
- Allow for natural reseeding if desired
- Provide shade during the hottest part of the day.
Lemongrass Care Tips
Lemongrass is relatively easy to grow outdoors in warm climates with ample sunlight. Indoor cultivation is challenging due to high light requirements. It needs regular watering, fertilization, and repotting due to its fast growth and rhizomatous nature. Toxicity to pets is a major concern.
- Provide at least 6 hours of direct sunlight daily.
- Water deeply when the top inch of soil is dry.
- Fertilize regularly during the growing season.
- Protect from frost in colder climates.
- Divide the plant every 1-2 years to prevent overcrowding.
⚠️ Common Problems & Solutions — Plant Care Comparison
Herb Robert
Lemongrass
❓ Frequently Asked Questions — Comparing These Plants
Herb Robert
What are the light requirements for Herb Robert?
Herb Robert thrives in partial shade, which mimics its natural woodland habitat. While it can tolerate full sun, especially in cooler climates, excessive direct sunlight can scorch its delicate foliage. Ideally, provide it with 4-6 hours of indirect sunlight per day. An east-facing window is often a good choice, providing morning sun and afternoon shade. If growing it indoors, consider supplementing with a grow light if natural light is insufficient. Observe the plant for signs of stress, such as yellowing or browning leaves, which may indicate too much direct sunlight. Adjust its placement accordingly to ensure optimal light exposure.
How do I care for Herb Robert?
Herb Robert thrives in partial shade to full sun, although partial shade is preferable, especially in hotter climates. Water regularly, keeping the soil consistently moist but not waterlogged. Allow the top inch of soil to dry out slightly between waterings. Fertilize with a balanced liquid fertilizer every 4-6 weeks during the growing season (spring and summer) to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage further flowering. Herb Robert prefers well-draining soil. Prune back leggy stems to maintain a compact shape. Provide good air circulation to prevent fungal diseases. Repot only when necessary, typically every 1-2 years, using a well-draining potting mix. Monitor for pests such as aphids and spider mites and treat accordingly.
How do I propagate Herb Robert?
Herb Robert can be propagated easily through seeds, division, or stem cuttings. For division, gently separate the root ball into smaller clumps and replant them in individual pots. For stem cuttings, take 4-6 inch cuttings from healthy stems, remove the lower leaves, and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix and keep them moist until they root. Seeds can be sown directly into the soil in spring or fall. Maintain consistent moisture and provide indirect light. The seeds germinate easily. The plant self seeds readily. Keep in mind that this plant can become invasive in certain areas.
Lemongrass
What are the light requirements for Lemongrass?
Lemongrass demands bright, indirect sunlight for optimal growth. Insufficient light can lead to leggy growth and reduced essential oil production, diminishing its characteristic aroma. A south- or east-facing window is ideal, providing ample light without direct scorching. If direct sunlight is unavoidable, filter it with a sheer curtain. Rotate the plant regularly to ensure even light exposure on all sides. If natural light is inadequate, supplement with a grow light for at least 6 hours per day. Monitor leaf color; pale or yellowing leaves may indicate too much direct sunlight, while elongated stems suggest insufficient light.
How do I care for Lemongrass?
Lemongrass thrives with bright, indirect sunlight, needing at least 6 hours daily. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain a consistently moist soil, but avoid overwatering. A well-draining potting mix is crucial for healthy growth. Fertilize every 2-4 weeks during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Maintain humidity levels around 50-60% by misting regularly or using a humidifier. Prune regularly to encourage bushier growth and remove any dead or yellowing leaves. Repot annually in spring to provide fresh soil and more room for growth. Protect from frost, as Lemongrass is sensitive to cold temperatures. Ensure good air circulation to prevent fungal diseases.
How do I propagate Lemongrass?
Lemongrass can be easily propagated through division, stem cuttings, or air layering. For division, carefully separate the plant clump into smaller sections, ensuring each section has healthy roots. Replant each section in a separate pot with well-draining soil. For stem cuttings, take a healthy stem cutting about 4-6 inches long. Remove the lower leaves and place the cutting in water. Once roots develop, transplant it into soil. Air layering involves making a small cut on a stem, wrapping it with moist sphagnum moss, and covering it with plastic wrap. Once roots emerge through the moss, cut the stem below the roots and plant it in soil. Keep the soil consistently moist and provide bright, indirect light for successful propagation.
Last updated: April 26, 2026 — Plant care data reviewed and verified by our editorial team.