Crepe Myrtle vs Flowering Onion Plant Comparison

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

Crepe Myrtle

Crepe Myrtle

Lagerstroemia indica

VS
Flowering Onion

Flowering Onion

Allium spp.

Crepe Myrtle

Crepe Myrtle

Lagerstroemia indica

Crepe Myrtles are deciduous trees or large shrubs known for their vibrant summer flowers, attractive peeling bark, and colorful fall foliage. They typically grow to heights of 15-25 feet outdoors, though dwarf varieties exist. The flowers come in shades of pink, red, white, and purple, with a crinkled, crepe-like texture. They are primarily grown as ornamental trees in gardens and landscapes for their year-round visual interest. Due to their high light requirements and large size, they are not suitable for indoor growing.

Lythraceae Native to China and Korea
✨ Features: Beautiful summer flowers, attractive peeling bark, colorful fall foliage
📖 Read Complete Crepe Myrtle Guide
Flowering Onion

Flowering Onion

Allium spp.

Flowering onions, or ornamental alliums, are bulbous perennials grown for their showy, spherical flower heads composed of numerous small, star-shaped flowers. They come in various sizes and colors, ranging from white and pink to purple and deep burgundy. Most are outdoor plants, thriving in gardens and borders. While some smaller varieties can be grown in containers, they are not ideally suited for indoor environments due to their high light requirements and dormancy needs. People grow them for their striking blooms, architectural interest, and ability to attract pollinators.

Amaryllidaceae Various species originate from different regions, including Europe, Asia, and North America.
✨ Features: Attracts pollinators, deer-resistant, long-lasting blooms.
📖 Read Complete Flowering Onion Guide

Quick Plant Comparison

Feature Crepe Myrtle Flowering Onion
Light Full sun (at least 6-8 hours of direct sunlight per day) Full sun (at least 6-8 hours of direct sunlight per day)
Watering Outdoors: Once or twice a week during the growing season, less frequently during dormancy. Indoors (not recommended): Would need very frequent watering due to high light needs. Every 1-2 weeks during the growing season, less frequently during dormancy.
Humidity 30-50% 40-60%
Temperature 18-32°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Not suitable for indoor growing; outdoors: 4.5-7.5 meters (15-25 feet) Variable, depending on the species, but typically 30-150 cm outdoors. Indoors, expect smaller sizes if grown in containers.
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, slightly acidic soil Well-draining soil, such as a mix of potting soil, sand, and perlite.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes monthly (pruning, fertilizing, pest control) 10 minutes weekly during the growing season.

🔬 Botanical Information — Comparing These Plants

Crepe Myrtle

Scientific Name Lagerstroemia indica
Family Lythraceae
Native To Native to China and Korea
Also Known As Crepe Myrtle, Crape Myrtle
Leaves The leaves are small, oval-shaped, and dark green in summer, turning to shades of yellow, orange, and red in the fall. They are arranged oppositely or alternately on the branches.
Flowers Crepe Myrtles produce large clusters of crinkled, crepe-like flowers in summer. The flowers come in shades of pink, red, white, and purple. They do not flower indoors.

Flowering Onion

Scientific Name Allium spp.
Family Amaryllidaceae
Native To Various species originate from different regions, including Europe, Asia, and North America.
Also Known As Flowering Onion, Ornamental Onion, Allium
Leaves The leaves are typically linear or strap-shaped, often with a bluish-green hue. They emerge from the base of the plant and may wither as the plant flowers.
Flowers Flowering onions produce showy, spherical flower heads composed of numerous small, star-shaped flowers. The flowers come in various colors, including white, pink, purple, and burgundy. They rarely flower indoors due to light requirements.

📏 Size & Growth — Plant Comparison

Crepe Myrtle

Height Not suitable for indoor growing; outdoors: 4.5-7.5 meters (15-25 feet)
Spread Outdoors: 4.5-7.5 meters (15-25 feet)
Growth Rate Moderate
Growth Pattern Crepe Myrtles typically grow as multi-stemmed trees or large shrubs with an upright, spreading habit. They can be pruned to a single trunk if desired.

Flowering Onion

Height Variable, depending on the species, but typically 30-150 cm outdoors. Indoors, expect smaller sizes if grown in containers.
Spread Variable, depending on the species, typically 15-30 cm. Some species can spread via bulb offsets.
Growth Rate Moderate
Growth Pattern Upright, with basal leaves emerging from the bulb and a tall flower stalk rising above the foliage. The flower heads are typically spherical and composed of numerous small flowers.

🌱 Propagation — Comparing Plant Growth

Crepe Myrtle

Methods: Stem cuttings, Seed

Difficulty: Moderate

Tips: Take softwood cuttings in late spring or early summer. Dip in rooting hormone and plant in well-draining soil. Keep moist and warm. Seeds can be sown in spring after stratification.

Flowering Onion

Methods: Bulb offsets, Seed

Difficulty: Moderate

Tips: Separate bulb offsets from the main bulb in the fall and replant them. Sow seeds in the spring after a period of cold stratification.

✨ Benefits & Features — Comparing Plant Value

Crepe Myrtle

Crepe Myrtles are known for their long blooming period and attractive peeling bark. The flowers have a unique, crepe-like texture, giving the tree its common name.

  • ✓ Provides beautiful summer flowers
  • ✓ Offers year-round visual interest with attractive bark and fall color
  • ✓ Attracts pollinators to the garden
  • ✓ Provides shade in the summer
  • ✓ Relatively low-maintenance once established
  • ⚠️ Toxic to pets

Flowering Onion

Flowering onions are known for their distinctive spherical flower heads, which can range in size from a golf ball to a softball. They offer a unique architectural element in the garden and attract beneficial insects.

  • ✓ Attracts pollinators to the garden
  • ✓ Deer-resistant, protecting other plants
  • ✓ Adds architectural interest with unique flower shapes
  • ✓ Provides long-lasting blooms for visual appeal
  • ✓ Low-maintenance once established
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Crepe Myrtle

Repotting Not applicable for outdoor trees. If grown in a container (not recommended), repot every 2-3 years.
Pruning Prune in late winter or early spring to remove dead or crossing branches and to shape the tree. Avoid excessive pruning, which can lead to weak growth.
Fertilizing Balanced fertilizer (10-10-10) in spring and early summer, diluted to half strength.
Seasonal Care Spring: Fertilize and prune. Summer: Water regularly and monitor for pests. Fall: Enjoy the colorful foliage. Winter: Protect from extreme cold in colder climates.

Flowering Onion

Repotting Not typically repotted if grown outdoors. If grown in containers, repot every 2-3 years in fresh soil.
Pruning Remove spent flower heads to prevent seed formation and encourage bulb growth. Cut back foliage after it has completely died back in the fall.
Fertilizing Balanced fertilizer (10-10-10) diluted to half strength, applied once in early spring and again after flowering.
Seasonal Care In spring, fertilize and water regularly as new growth emerges. In summer, enjoy the blooms. In fall, allow foliage to die back naturally and reduce watering. In winter, provide a dry, cool dormancy period.

🌞 Light Requirements

Crepe Myrtle

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

Low light tolerant: ❌ No

Flowering Onion

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

Low light tolerant: ❌ No

💧 Watering Needs

Crepe Myrtle

Water deeply when the top few inches of soil are dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting leaves and stunted growth. Signs of overwatering include yellowing leaves and soggy soil.

Flowering Onion

Water thoroughly when the top inch of soil is dry. Avoid overwatering, which can lead to bulb rot. Reduce watering during dormancy. Signs of overwatering include yellowing leaves and a mushy bulb. Underwatering is indicated by wilting leaves and stunted growth.

🌡️ Temperature & Humidity

Crepe Myrtle

Temperature: 18-32°C

Humidity: 30-50%

Flowering Onion

Temperature: 15-25°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Crepe Myrtle

Crepe Myrtle

Lagerstroemia indica
Care: Expert Time: 30 minutes monthly (pruning, fertilizing, pest control) Beginner: No

Gardeners with sunny outdoor spaces who want a beautiful, flowering tree with year-round interest.

✅ Choose This Plant If...

  • You want a tree with stunning summer blooms.
  • You appreciate year-round visual interest with attractive bark and fall color.
  • You have a sunny outdoor space.
  • You are looking for a relatively low-maintenance tree once established.
  • You want to attract pollinators to your garden.

❌ Skip This Plant If...

  • You have limited sunlight.
  • You are looking for an indoor plant.
  • You have pets that might ingest the plant.
  • You live in a very cold climate where the tree may not thrive.
📍 Ideal Location: Outdoor garden or landscape with full sun exposure
🎨 Style: Traditional, Cottage, Southern
🏠 Apartment Friendly: No
⚠️ All parts of the Crepe Myrtle are considered toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and abdominal pain. The fruit and seeds are especially toxic.
Flowering Onion

Flowering Onion

Allium spp.
Care: Expert Time: 10 minutes weekly during the growing season. Beginner: No

Gardeners looking for striking, low-maintenance perennials to add architectural interest and attract pollinators to their outdoor spaces.

✅ Choose This Plant If...

  • You want a deer-resistant plant for your garden
  • You want to attract pollinators like bees and butterflies
  • You appreciate unique, globe-shaped flowers
  • You have a sunny garden space
  • You want a low-maintenance perennial that returns year after year

❌ Skip This Plant If...

  • You have pets that might ingest the plant
  • You don't have a sunny outdoor space
  • You are looking for an easy indoor plant
📍 Ideal Location: Outdoor garden beds, borders, or rock gardens with full sun exposure.
🎨 Style: Cottage, Naturalistic, Modern
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the bulbs, contain organosulfides that can cause gastrointestinal upset, anemia, and damage to red blood cells in dogs, cats, and horses. Symptoms include vomiting, diarrhea, weakness, and loss of appetite.

🎯 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

Crepe Myrtle Care Tips

Crepe Myrtles are outdoor trees that require full sun and well-draining soil. They are not suitable for indoor growing due to their high light requirements and large size. Attempting to grow them indoors will likely result in a weak, unhealthy plant.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for optimal flowering.
  • Prune in late winter or early spring to remove dead or crossing branches.
  • Fertilize in spring and early summer with a balanced fertilizer.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: In colder climates, protect young trees from frost by wrapping the trunk with burlap. Reduce watering during the winter months.
☀️ Summer: Water regularly during the summer months, especially during dry spells. Monitor for pests and diseases and treat promptly.

Flowering Onion Care Tips

Flowering onions are primarily outdoor plants requiring full sun and well-draining soil. Indoor cultivation is challenging due to their high light needs and dormancy requirements. They are toxic to pets, so caution is needed if grown in areas accessible to animals. Regular watering and occasional fertilization are necessary for optimal growth.

  • Plant bulbs in well-draining soil to prevent rot
  • Provide full sun for optimal flowering
  • Water deeply but infrequently, allowing the soil to dry out between waterings
  • Fertilize in early spring and after flowering to promote bulb growth
  • Remove spent flower heads to encourage bulb development
❄️ Winter: Allow foliage to die back naturally. Provide a dry, cool dormancy period. Avoid overwatering.
☀️ Summer: Water regularly during dry periods. Provide support for tall flower stalks if needed. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Crepe Myrtle

Common Issues: Powdery mildew, Aphids, Japanese beetles, Root rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap. Japanese beetles: Handpick or use insecticides. Root rot: Ensure well-draining soil and avoid overwatering.

Flowering Onion

Common Issues: Bulb rot, Onion white rot, Allium leaf miner, Aphids
Solutions: Ensure well-draining soil and avoid overwatering to prevent bulb rot. Remove and destroy infected plants to control onion white rot. Use insecticidal soap to control allium leaf miner and aphids.

❓ Frequently Asked Questions — Comparing These Plants

Crepe Myrtle

What are the light requirements for Crepe Myrtle?

Indoor Crepe Myrtles require bright, indirect light to thrive and produce their signature blooms. A south- or west-facing window is ideal, providing several hours of sunlight daily. If natural light is insufficient, supplement with grow lights. Rotate the plant regularly to ensure even light exposure on all sides. Avoid placing the Crepe Myrtle in direct sunlight, which can scorch the leaves. Signs of insufficient light include leggy growth, pale leaves, and a lack of flowering. During the winter months, when light levels are lower, consider providing additional artificial light to support healthy growth.

How do I care for Crepe Myrtle?

To ensure your indoor Crepe Myrtle thrives, provide bright, indirect light, ideally from a south- or west-facing window. Water thoroughly when the top inch of soil feels dry, ensuring proper drainage to prevent root rot. Maintain a moderate humidity level by misting the foliage regularly or using a humidifier. Fertilize during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Prune in late winter or early spring to remove dead or crossing branches and to shape the plant. Repot every two to three years into a slightly larger pot with well-draining potting mix. Monitor for pests such as aphids or spider mites and treat promptly. Maintain stable temperatures between 65-75°F (18-24°C).

How do I propagate Crepe Myrtle?

Crepe Myrtles can be propagated through stem cuttings or air layering. For stem cuttings, take a 4-6 inch cutting from new growth in the spring or summer. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a well-draining potting mix and keep it moist in a humid environment until roots develop. For air layering, make a small incision on a stem, apply rooting hormone, and wrap the area with moist sphagnum moss. Cover the moss with plastic wrap and secure it tightly. Once roots develop, cut the stem below the wrapped area and plant it in a pot. Rooting can take several weeks to a few months. Maintain consistent moisture.

Flowering Onion

What are the light requirements for Flowering Onion?

Flowering Onions need ample sunlight to produce vibrant blooms. Aim for at least 6 hours of direct sunlight per day. If growing indoors, place them near a south-facing window where they can receive the most sunlight. Insufficient light can result in weak stems, pale foliage, and a lack of flowers. If natural light is limited, supplement with grow lights to provide the necessary intensity. Rotate the plant regularly to ensure even light exposure on all sides. Consider using a light meter to measure the light intensity and adjust the plant’s position accordingly.

How do I care for Flowering Onion?

Flowering Onions thrive in well-draining soil and require full sun to partial shade for optimal growth and flowering. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain away. Avoid overwatering, as this can lead to bulb rot. Fertilize during the growing season (spring and summer) with a balanced, slow-release fertilizer or a liquid feed diluted to half strength every 2-4 weeks to promote abundant blooms. Deadhead spent flowers to encourage further blooming and prevent seed production. Protect from frost in colder climates by mulching heavily or moving potted plants indoors. Repot every 2-3 years as needed, using a pot slightly larger than the previous one. Ensure good air circulation around the plants to prevent fungal diseases.

How do I propagate Flowering Onion?

Flowering Onions can be propagated through division, a relatively simple method. In the fall, after the foliage has died back, carefully dig up the bulbs. Separate the smaller bulblets from the main bulb. Replant the bulblets in well-draining soil, spacing them a few inches apart. Water thoroughly and mulch to protect them from frost. They may take a year or two to reach flowering size. Stem cuttings and keiki propagation are not applicable to Flowering Onions, as they are bulbous plants. Division is the primary method for increasing your stock of these beautiful plants. Ensure the bulblets have some roots attached for best results.

Last updated: May 4, 2026 — Plant care data reviewed and verified by our editorial team.