Lemon Grass vs Obedient Plant Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Lemon Grass

Lemon Grass

Cymbopogon citratus

VS
Obedient Plant

Obedient Plant

Physostegia virginiana

Lemon Grass

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.

Poaceae Southeast Asia (India, Sri Lanka, Malaysia, Thailand)
✨ Features: Aromatic leaves, culinary uses, potential medicinal properties
📖 Read Complete Lemon Grass Guide
Obedient Plant

Obedient Plant

Physostegia virginiana

Physostegia virginiana, commonly known as Obedient Plant, is a herbaceous perennial native to North America. It's characterized by its upright growth habit and lance-shaped, toothed leaves. The plant produces spikes of tubular flowers in shades of pink, lavender, or white during late summer and early fall. It gets its name from the fact that if you gently bend the flowers on the stem, they will stay in the position you put them, hence 'obedient'. Primarily an outdoor plant, it's grown in gardens for its late-season blooms and attractiveness to pollinators. Indoor cultivation is challenging due to its high light and space requirements.

Lamiaceae Eastern and Central North America
✨ Features: Attracts butterflies and hummingbirds, unique flower positioning.
📖 Read Complete Obedient Plant Guide

Quick Plant Comparison

Feature Lemon Grass Obedient Plant
Light Full sun (at least 6-8 hours of direct sunlight daily) Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth and flowering.
Watering Every 2-3 days during the growing season, less frequently in winter (every 7-10 days) Every 3-7 days outdoors, less frequently if in partial shade or cooler conditions. Indoor cultivation is not recommended.
Humidity 40-60% 30-50%
Temperature 18-30°C 15-27°C
Care Level Expert Expert
Growth Rate Fast Fast
Max Height 0.6-1.2 meters (2-4 feet) indoors, up to 1.8 meters (6 feet) outdoors Outdoor: 60-120 cm. Indoor: Not recommended, but if attempted, expect significantly stunted growth.
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, loamy soil. A mix of potting soil, sand, and perlite is suitable. Well-drained soil, loamy or sandy soil is preferred. Tolerates a range of soil pH levels.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 15 minutes weekly (outdoor)

🔬 Botanical Information — Comparing These Plants

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.

Obedient Plant

Scientific Name Physostegia virginiana
Family Lamiaceae
Native To Eastern and Central North America
Also Known As Obedient Plant, False Dragonhead
Leaves Lance-shaped, toothed leaves that are typically green. They are arranged oppositely along the stem and have a slightly rough texture.
Flowers Flowers are tubular and arranged in spikes. They come in shades of pink, lavender, or white. Flowering occurs in late summer and early fall. Rarely flowers indoors.

📏 Size & Growth — Plant Comparison

Lemon Grass

Height 0.6-1.2 meters (2-4 feet) indoors, up to 1.8 meters (6 feet) outdoors
Spread 0.6-0.9 meters (2-3 feet), spreads via rhizomes
Growth Rate Fast
Growth Pattern Lemon Grass grows in dense clumps, with multiple stalks emerging from a central base. It has an upright growth habit, with leaves arching outwards. It spreads via rhizomes, which can lead to the formation of larger clumps over time.

Obedient Plant

Height Outdoor: 60-120 cm. Indoor: Not recommended, but if attempted, expect significantly stunted growth.
Spread 30-60 cm. Spreads aggressively via rhizomes.
Growth Rate Fast
Growth Pattern Upright, clump-forming perennial that spreads aggressively via rhizomes. It can form dense colonies if not contained.

🌱 Propagation — Comparing Plant 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.

Obedient Plant

Methods: Division, Seed, Stem cuttings

Difficulty: Easy

Tips: Division is best done in spring or fall. For stem cuttings, take cuttings in late spring or early summer and root in water or moist soil. Seeds can be sown directly in the garden in fall or stratified and sown in spring.

✨ Benefits & Features — Comparing Plant Value

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

Obedient Plant

The Obedient Plant is known for its unique flower positioning; the flowers stay in place when gently moved. It's also a late-season bloomer, providing color when many other perennials are finished flowering.

  • ✓ Attracts pollinators to the garden
  • ✓ Provides late-season color
  • ✓ Easy to propagate
  • ✓ Low maintenance once established
  • ✓ Adds a unique touch to floral arrangements
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Lemon Grass

Repotting Every 1-2 years, or when the plant becomes root-bound. Divide the plant during repotting to control its spread.
Pruning Regularly trim dead or yellowing leaves. Cut back the plant in late winter or early spring to encourage new growth.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-4 weeks during the growing season.
Seasonal Care In winter, reduce watering and protect from frost. In summer, ensure adequate moisture and sunlight. Bring indoors before the first frost in colder climates.

Obedient Plant

Repotting Not recommended for indoor growing. If attempted, repot annually in spring to control rhizomatous spread.
Pruning Cut back spent flower stalks to encourage reblooming. Prune aggressively in spring to control size and shape.
Fertilizing Balanced fertilizer (10-10-10) in spring as new growth emerges. Avoid over-fertilizing, which can lead to leggy growth.
Seasonal Care Spring: Divide if needed, fertilize. Summer: Monitor for pests and diseases, water regularly. Fall: Cut back spent flower stalks, divide if needed. Winter: Dormant, minimal watering.

🌞 Light Requirements

Lemon Grass

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Obedient Plant

Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth and flowering.

Low light tolerant: ❌ No

💧 Watering Needs

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.

Obedient Plant

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. In containers, ensure proper drainage. Signs of underwatering include wilting leaves, while overwatering can manifest as yellowing leaves and a soggy soil.

🌡️ Temperature & Humidity

Lemon Grass

Temperature: 18-30°C

Humidity: 40-60%

Obedient Plant

Temperature: 15-27°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Lemon Grass

Lemon Grass

Cymbopogon citratus
Care: Expert Time: 15 minutes weekly Beginner: No

Experienced 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
📍 Ideal Location: Sunny patio, herb garden, or a very bright, south-facing window indoors
🎨 Style: Tropical, Bohemian, Natural
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Lemon Grass is toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and abdominal pain. The leaves are the primary toxic part.
Obedient Plant

Obedient Plant

Physostegia virginiana
Care: Expert Time: 15 minutes weekly (outdoor) Beginner: No

Gardeners looking for a late-season blooming perennial that attracts pollinators.

✅ Choose This Plant If...

  • You want a late-season bloomer that attracts pollinators.
  • You enjoy unique flower arrangements and the 'obedient' nature of the blooms.
  • You have a sunny garden space and want a low-maintenance perennial.
  • You want to attract butterflies and hummingbirds to your garden.
  • You are looking for a plant that is easy to propagate.

❌ Skip This Plant If...

  • You have limited sunlight indoors.
  • You don't want a plant that spreads aggressively.
  • You have pets that may ingest the plant.
📍 Ideal Location: Outdoor garden, sunny border, meadow garden
🎨 Style: Cottage, Naturalistic, Traditional
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Obedient Plant is toxic to dogs, cats, and horses. The toxic principle is unknown. Symptoms include gastrointestinal upset (vomiting, diarrhea), and dermatitis.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ 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

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
❄️ Winter: In colder climates, bring Lemon Grass indoors before the first frost. Reduce watering frequency and provide as much light as possible. Avoid fertilizing during the winter months. Maintain temperatures above 10°C (50°F).
☀️ Summer: Ensure adequate moisture and sunlight during the summer months. Water deeply and regularly, especially during hot, dry periods. Fertilize every 2-4 weeks with a balanced liquid fertilizer. Protect from strong winds, which can damage the leaves.

Obedient Plant Care Tips

Obedient Plant is primarily an outdoor plant and requires full sun and well-drained soil. Indoor cultivation is challenging due to its high light requirements and aggressive spreading habit. It can quickly outgrow containers and may not flower properly indoors. Requires careful monitoring of water and fertilizer.

  • Plant in well-drained soil to prevent root rot.
  • Provide full sun for optimal flowering.
  • Divide every few years to control spread and rejuvenate the plant.
  • Deadhead spent flowers to encourage more blooms.
  • Monitor for powdery mildew and rust, especially in humid conditions.
❄️ Winter: Cut back dead foliage in late fall or early spring. Mulch around the base of the plant to protect the roots in colder climates. Minimal watering is needed during dormancy.
☀️ Summer: Water regularly during dry spells. Monitor for pests and diseases. Deadhead spent flowers to encourage more blooms. Provide support if the plant becomes leggy or top-heavy.

⚠️ Common Problems & Solutions — Plant Care Comparison

Lemon Grass

Common Issues: Root rot, spider mites, insufficient sunlight, brown leaf tips
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Spider mites: Increase humidity and treat with insecticidal soap. Insufficient sunlight: Move to a brighter location or supplement with grow lights. Brown leaf tips: Increase humidity and ensure consistent watering.

Obedient Plant

Common Issues: Powdery mildew, Rust, Aggressive spreading, Leggy growth (if not enough light)
Solutions: Powdery mildew: Improve air circulation and apply fungicide. Rust: Remove infected leaves and apply fungicide. Aggressive spreading: Plant in containers or use barriers to contain rhizomes. Leggy growth: Provide more sunlight and prune back to encourage bushier growth.

❓ Frequently Asked Questions — Comparing These Plants

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.

Obedient Plant

What are the light requirements for Obedient Plant?

Obedient Plant thrives best in full sun, requiring at least 6 hours of direct sunlight per day to produce abundant blooms and maintain strong, upright growth. In hotter climates, some afternoon shade can be beneficial to prevent leaf scorch. Insufficient sunlight can lead to leggy growth, reduced flowering, and weaker stems. When grown indoors, place Obedient Plant near a sunny window, such as a south-facing or west-facing exposure. Rotate the plant regularly to ensure even light exposure on all sides. Supplemental lighting may be necessary during winter months or in areas with limited natural light.

How do I care for Obedient Plant?

Obedient Plant thrives in full sun to partial shade and prefers moist, well-drained soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize in early spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage further blooming. Be aware that Obedient Plant can be aggressive; consider planting it in containers or using barriers to control its spread. Prune back stems after flowering to maintain shape and prevent excessive self-seeding. Monitor for pests like aphids and spider mites, and treat as needed. Provide adequate air circulation to prevent fungal diseases.

How do I propagate Obedient Plant?

Obedient Plant can be easily propagated through division, stem cuttings, or seeds. Division is best done in early spring or fall by separating the rhizomes and replanting them. For stem cuttings, take 4-6 inch cuttings from healthy stems in late spring or early summer. Remove the lower leaves and plant the cuttings in moist potting mix. Keep the cuttings humid by covering them with a plastic bag or dome. Seeds can be sown directly in the garden in fall or started indoors in early spring. Keep the soil moist until germination.

Last updated: April 22, 2026 — Plant care data reviewed and verified by our editorial team.