Lemon Grass vs Spiraea 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
Spiraea

Spiraea

Spiraea japonica

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
Spiraea

Spiraea

Spiraea japonica

Spiraea japonica is a deciduous shrub known for its vibrant flower clusters and attractive foliage. Typically grown outdoors, it features lance-shaped leaves that emerge in spring, often with bronze or reddish hues, maturing to green. The plant produces numerous small pink or white flowers in flat-topped clusters (corymbs) during the summer. It's a popular choice for landscaping due to its relatively low maintenance, showy blooms, and adaptability to various soil conditions. While primarily an outdoor plant, some gardeners might attempt to grow it in large containers, but success is limited due to its need for full sun and dormancy.

Rosaceae Japan, Korea, China
✨ Features: Attractive foliage, showy flower clusters, attracts pollinators.
📖 Read Complete Spiraea Guide

Quick Plant Comparison

Feature Lemon Grass Spiraea
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 flowering.
Watering Every 2-3 days during the growing season, less frequently in winter (every 7-10 days) Every 7-10 days during the growing season, less frequently in winter.
Humidity 40-60% 30-50%
Temperature 18-30°C 15-27°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height 0.6-1.2 meters (2-4 feet) indoors, up to 1.8 meters (6 feet) outdoors Typically 0.6-1.2 meters indoors (highly unlikely to thrive indoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, loamy soil. A mix of potting soil, sand, and perlite is suitable. Well-draining soil. A mix of garden soil, compost, and perlite is suitable.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 15 minutes weekly (outdoors)

🔬 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.

Spiraea

Scientific Name Spiraea japonica
Family Rosaceae
Native To Japan, Korea, China
Also Known As Japanese Spiraea, Meadowsweet
Leaves The leaves of Spiraea japonica are lance-shaped to oval, typically 2.5-7.5 cm long. They are arranged alternately along the stems. The foliage often emerges in spring with bronze or reddish hues, maturing to green in summer and sometimes turning reddish-purple in the fall.
Flowers Spiraea japonica produces numerous small pink or white flowers in flat-topped clusters (corymbs) during the summer. Flowering is unlikely 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.

Spiraea

Height Typically 0.6-1.2 meters indoors (highly unlikely to thrive indoors)
Spread 0.9-1.5 meters (outdoors)
Growth Rate Moderate
Growth Pattern Spiraea japonica grows as a rounded, deciduous shrub with an upright to spreading habit. It typically forms a dense, multi-stemmed plant.

🌱 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.

Spiraea

Methods: Stem cuttings, Seed, Division

Difficulty: Easy

Tips: Take softwood cuttings in late spring or early summer. Dip the cut end in rooting hormone and plant in a well-draining potting mix. Keep the cuttings moist and in a humid environment until roots develop. Hardwood cuttings can be taken in late fall or winter.

✨ 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

Spiraea

Spiraea japonica is known for its vibrant flower clusters and attractive foliage that changes color throughout the season. Its relatively low maintenance requirements make it a popular choice for landscaping.

  • ✓ Attracts pollinators to the garden.
  • ✓ Provides colorful blooms in summer.
  • ✓ Relatively low-maintenance once established.
  • ✓ Adds visual interest with changing foliage colors.
  • ✓ Can be used for erosion control on slopes (outdoors).
  • ⚠️ 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.

Spiraea

Repotting Not applicable for outdoor planting. If grown in a container (not recommended), repot every 2-3 years.
Pruning Prune in late winter or early spring to remove dead or damaged wood and to shape the plant. Deadhead spent flowers to encourage further blooming.
Fertilizing Balanced slow-release fertilizer in early spring. Avoid over-fertilizing.
Seasonal Care Spring: Fertilize and prune. Summer: Water regularly and monitor for pests. Fall: Reduce watering and prepare for dormancy. Winter: Provide protection from extreme cold.

🌞 Light Requirements

Lemon Grass

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

Low light tolerant: ❌ No

Spiraea

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

Spiraea

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. During hot summer months, more frequent watering may be necessary. Reduce watering in the fall and winter.

🌡️ Temperature & Humidity

Lemon Grass

Temperature: 18-30°C

Humidity: 40-60%

Spiraea

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.
Spiraea

Spiraea

Spiraea japonica
Care: Expert Time: 15 minutes weekly (outdoors) Beginner: No

Experienced gardeners who want a low-maintenance flowering shrub for their outdoor landscape.

✅ Choose This Plant If...

  • You want a low-maintenance flowering shrub for your garden.
  • You need a plant that attracts butterflies and other pollinators.
  • You desire a shrub with colorful foliage that changes throughout the season.
  • You want a plant that is relatively easy to propagate.
  • You need a plant that is adaptable to various soil conditions (outdoors).

❌ Skip This Plant If...

  • You are looking for an indoor plant.
  • You have pets that might ingest the plant.
  • You don't have a sunny outdoor location.
  • You don't want to deal with potential pest or disease issues.
📍 Ideal Location: Outdoor garden, border, or foundation planting.
🎨 Style: Cottage, Traditional, Naturalistic
🏠 Apartment Friendly: No
⚠️ Spiraea contains cyanogenic glycosides, which can release cyanide when ingested. All parts of the plant are potentially toxic, especially to dogs, cats, and horses. Symptoms include vomiting, diarrhea, difficulty breathing, and in severe cases, seizures or coma.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

📈

Lemon Grass has fast growth, while Spiraea grows moderate.

💡 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.

Spiraea Care Tips

Spiraea japonica is primarily an outdoor shrub and is challenging to grow indoors. It requires full sun, well-draining soil, and a period of dormancy. Indoor cultivation is unlikely to be successful long-term due to the plant's specific environmental needs, including cold stratification for optimal flowering. Expect significantly reduced growth and flowering indoors.

  • Plant in a location with full sun for best flowering.
  • Prune annually to maintain shape and encourage new growth.
  • Water deeply during dry periods, especially when newly planted.
  • Apply a layer of mulch around the base of the plant to retain moisture and suppress weeds.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Outdoors, provide protection from extreme cold and heavy snow. Indoors (not recommended), reduce watering and ensure adequate ventilation.
☀️ Summer: Outdoors, water regularly during dry periods and monitor for pests. Indoors (not recommended), provide adequate sunlight and ventilation.

⚠️ 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.

Spiraea

Common Issues: Powdery mildew, Aphids, Spider mites, Root rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. | Aphids: Spray with insecticidal soap or neem oil. | Spider mites: Increase humidity and spray with miticide. | Root rot: Ensure well-draining soil and avoid overwatering.

❓ 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.

Spiraea

What are the light requirements for Spiraea?

Spiraea thrives in full sun, needing at least six hours of direct sunlight each day to produce abundant blooms. Insufficient light can result in fewer flowers and leggy growth. When planting Spiraea, choose a location that receives ample sunlight throughout the day. Morning sun is particularly beneficial, as it helps to dry the foliage and reduce the risk of fungal diseases. If growing Spiraea in a partially shaded area, ensure it receives at least four hours of direct sunlight. Be aware that reduced sunlight may result in weaker stems and less vibrant flower color. Avoid planting Spiraea in heavily shaded areas, as this can significantly hinder its growth and flowering potential.

How do I care for Spiraea?

Spiraea are relatively easy to care for, making them a great choice for beginners. They thrive best in well-drained soil and require at least six hours of sunlight daily to promote abundant blooms. Water regularly, especially during dry spells, but avoid overwatering, which can lead to root rot. Fertilize in early spring with a balanced fertilizer to encourage healthy growth and flowering. Prune annually to maintain shape and remove dead or damaged branches. The timing of pruning depends on the specific Spiraea variety; spring-blooming types should be pruned after flowering, while summer-blooming types can be pruned in late winter or early spring. Protect young plants from extreme winter conditions with mulch. With proper care, Spiraea will reward you with years of beautiful blooms and vibrant foliage.

How do I propagate Spiraea?

Spiraea can be easily propagated through several methods. Stem cuttings are a popular choice: take 4-6 inch softwood cuttings in late spring or early summer. 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. Root division is another straightforward method, best done in early spring or fall. Carefully dig up the mature plant and divide the root ball into smaller sections, ensuring each section has healthy roots and stems. Replant the divisions in their new locations. While less common, layering can also be successful. Bend a low-lying branch to the ground, partially bury it, and secure it with a rock or landscape pin. Once roots have formed, sever the branch from the parent plant and transplant it.

Last updated: April 23, 2026 — Plant care data reviewed and verified by our editorial team.