Crepe Myrtle vs Onion Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
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.
Onion
Allium cepa
The onion (Allium cepa) is a biennial plant, typically grown as an annual, cultivated for its edible bulb. It features hollow, bluish-green leaves and a bulb that develops at the base of the plant. Onions are primarily grown outdoors in gardens or fields. While it's possible to sprout an onion indoors, it's not typically grown to full maturity as a houseplant due to its strong odor and specific environmental needs. People grow onions for culinary purposes, adding flavor to a wide variety of dishes.
Quick Plant Comparison
| Feature | Crepe Myrtle | Onion |
|---|---|---|
| Light | Full sun (at least 6-8 hours of direct sunlight per day) | Full sun (6-8 hours of direct sunlight daily) |
| 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 5-7 days, depending on weather and soil drainage |
| Humidity | 30-50% | 40-60% |
| Temperature | 18-32°C | 13-24°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) | Outdoors: 30-60 cm. Indoors (sprouted): Up to 30cm |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining, slightly acidic soil | Well-draining, fertile soil rich in organic matter |
| Beginner Friendly | ❌ No | With Caution |
| Weekly Maintenance | 30 minutes monthly (pruning, fertilizing, pest control) | 30 minutes weekly (weeding, watering, pest control) |
🔬 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. |
Onion
| Scientific Name | Allium cepa |
|---|---|
| Family | Amaryllidaceae |
| Native To | Central Asia |
| Also Known As | Onion, Bulb Onion, Common Onion |
| Leaves | The leaves are hollow, cylindrical, and bluish-green, growing directly from the bulb. They are typically 30-50 cm long and taper to a point. |
| Flowers | Onions produce a spherical umbel of small, white or purple flowers on a tall stalk. Flowering is more common in the second year of growth. Flowering rarely occurs indoors. |
📏 Size & Growth — Plant Comparison
Crepe Myrtle
Onion
🌱 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.
Onion
Methods: Seed, Bulb division
Difficulty: Easy
Tips: Start seeds indoors 8-10 weeks before the last frost or plant sets (small bulbs) directly in the garden after the last frost. For bulb division, separate small bulbs from a larger cluster and plant them individually.
✨ 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
Onion
The onion is a bulbous plant with a distinctive pungent odor and flavor. Its layers of fleshy scales form the edible bulb, which is used in a wide variety of culinary applications.
- ✓ Provides fresh, flavorful onions for cooking.
- ✓ Rich in vitamins and minerals.
- ✓ Can deter pests in the garden.
- ✓ Offers a rewarding gardening experience.
- ✓ Supports sustainable food practices.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Crepe Myrtle
Onion
🌞 Light Requirements
Crepe Myrtle
Full sun (at least 6-8 hours of direct sunlight per day)
Low light tolerant: ❌ No
Onion
Full sun (6-8 hours of direct sunlight daily)
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.
Onion
Water deeply when the top inch of soil is dry. Avoid overwatering, which can lead to bulb rot. Signs of overwatering include yellowing leaves and a soft, mushy bulb. Underwatering is indicated by wilting leaves and stunted growth.
🌡️ Temperature & Humidity
Crepe Myrtle
Temperature: 18-32°C
Humidity: 30-50%
Onion
Temperature: 13-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Crepe Myrtle
Lagerstroemia indicaGardeners 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.
Onion
Allium cepaGardeners looking to grow their own culinary onions.
✅ Choose This Plant If...
- You want to grow your own fresh onions for cooking.
- You have a sunny outdoor garden space.
- You enjoy the process of nurturing plants from seed to harvest.
- You want to control the quality and source of your food.
- You are looking for a companion plant to deter pests in your vegetable garden.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You lack a sunny outdoor space.
- You are sensitive to strong odors.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Crepe Myrtle needs full sun (at least 6-8 hours of direct sunlight per day), while Onion prefers full sun (6-8 hours of direct sunlight daily).
💡 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.
Onion Care Tips
Onions are primarily outdoor plants requiring full sun and well-drained soil. Growing them indoors is challenging due to their need for intense sunlight and the potential for strong odors. While sprouting an onion indoors is possible, achieving a mature bulb is difficult.
- Plant in well-drained soil amended with compost.
- Water deeply but infrequently, allowing the soil to dry slightly between waterings.
- Fertilize regularly during the growing season with a balanced fertilizer.
- Protect from pests and diseases with appropriate measures.
- Harvest when the tops begin to fall over and the bulbs are mature.
⚠️ Common Problems & Solutions — Plant Care Comparison
Crepe Myrtle
Onion
❓ 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.
Onion
What are the light requirements for Onion?
Flowering onions require ample sunlight to thrive and produce abundant blooms. Aim for at least 6-8 hours of direct sunlight per day. Inadequate light can lead to leggy growth, weak stems, and reduced flowering. If growing indoors, place your onion plant near a south-facing window where it can receive maximum sunlight exposure. If natural light is insufficient, supplement with grow lights. Rotate the plant regularly to ensure even light distribution and prevent it from leaning towards the light source. Monitor the foliage for signs of sunburn, which can occur if the plant is exposed to intense afternoon sun. Adjust the placement or provide shade if necessary.
How do I care for Onion?
Flowering onions thrive with proper care. Plant bulbs in well-draining soil in a sunny location. Water thoroughly after planting and then moderately, allowing the soil to dry slightly between waterings. Fertilize sparingly with a balanced fertilizer during the growing season, and increase phosphorus before blooming. Deadhead spent flowers to encourage continued blooming. Provide support for taller varieties to prevent drooping. In colder climates, protect bulbs with a layer of mulch during winter. Monitor for pests and diseases, and address promptly. Ensure good air circulation to prevent fungal issues. Repot container-grown onions every few years to refresh the soil. Regular check-ups will keep your onion plant healthy and flourishing.
How do I propagate Onion?
Flowering onions can be propagated through several methods. Division is the most common and easiest. When the plant is dormant, carefully dig up the clump and separate the bulbs. Replant the individual bulbs in well-draining soil. Stem cuttings are not typically used for onion propagation. Keiki (small plantlets that form on the flower stalk) are rare in onions. For bulb offsets, detach them carefully from the mother bulb and plant them separately. Water regularly and provide adequate sunlight. Propagation is best done in the fall or early spring. Ensure the new plants have adequate space to develop their root systems. With proper care, the propagated onions will develop into mature, flowering plants within a year or two.
Last updated: May 3, 2026 — Plant care data reviewed and verified by our editorial team.