Catnip vs Ornamental Onion Plant Comparison

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

Catnip

Catnip

Nepeta cataria

VS
Ornamental Onion

Ornamental Onion

Allium spp.

Catnip

Catnip

Nepeta cataria

Catnip is a herbaceous perennial plant known for its intoxicating effect on cats. It typically grows to a height of 50-100 cm, featuring grayish-green, heart-shaped leaves with serrated edges. The plant produces spikes of small, white or pale lavender flowers dotted with purple spots. While primarily grown outdoors, it can be cultivated indoors with sufficient light. People grow it for its appeal to cats, its use in herbal teas, and its purported medicinal properties.

Lamiaceae Native to Europe and Asia
✨ Features: Attracts cats, can be used in herbal teas, and is believed to have medicinal properties.
📖 Read Complete Catnip Guide
Ornamental Onion

Ornamental Onion

Allium spp.

Ornamental onions are bulbous perennials grown for their showy, spherical flower heads in shades of purple, pink, white, and yellow. The foliage is typically grass-like or strap-shaped and often dies back before or during flowering. They range in size from a few inches to several feet tall, depending on the species. These plants are primarily grown outdoors in gardens and borders for their architectural interest and pollinator-attracting blooms. While some smaller varieties can be grown in containers, they are generally not suited for indoor cultivation due to their high light requirements and dormancy needs.

Amaryllidaceae Various species originate from different regions across the Northern Hemisphere, including Europe, Asia, and North America.
✨ Features: Attracts pollinators, deer-resistant, long-lasting blooms, architectural interest
📖 Read Complete Ornamental Onion Guide

Quick Plant Comparison

Feature Catnip Ornamental Onion
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth. Full sun (at least 6-8 hours of direct sunlight daily)
Watering Every 7-10 days, depending on environmental conditions and pot size. Every 1-2 weeks during the growing season, less frequently during dormancy.
Humidity 40-60% 30-50%
Temperature 18-24°C 10-24°C
Care Level Moderate Expert
Growth Rate Moderate Moderate
Max Height 30-60 cm indoors 0.15-1.5 meters (depending on species)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, such as a mix of potting soil, perlite, and sand. Well-draining soil, such as a mix of garden soil, sand, and compost.
Beginner Friendly With Caution ❌ No
Weekly Maintenance 10 minutes weekly 5 minutes weekly during the growing season.

🔬 Botanical Information — Comparing These Plants

Catnip

Scientific Name Nepeta cataria
Family Lamiaceae
Native To Native to Europe and Asia
Also Known As Catmint, Catswort
Leaves The leaves are grayish-green, heart-shaped to ovate, and have serrated edges. They are typically 3-7 cm long and covered in fine hairs, giving them a slightly fuzzy texture.
Flowers Catnip produces small, white or pale lavender flowers dotted with purple spots. The flowers are arranged in spikes at the ends of the stems. It may flower indoors if given enough light, but flowering is more prolific outdoors.

Ornamental Onion

Scientific Name Allium spp.
Family Amaryllidaceae
Native To Various species originate from different regions across the Northern Hemisphere, including Europe, Asia, and North America.
Also Known As Ornamental Onion, Flowering Onion, Allium
Leaves The leaves are typically grass-like or strap-shaped, ranging in color from green to bluish-green. They emerge from the base of the plant and often die back before or during flowering. The leaves have a characteristic onion-like scent when crushed.
Flowers Ornamental onions produce showy, spherical flower heads composed of numerous small, star-shaped flowers. The flowers come in a variety of colors, including purple, pink, white, and yellow. They bloom in late spring or early summer and attract pollinators.

📏 Size & Growth — Plant Comparison

Catnip

Height 30-60 cm indoors
Spread 30-45 cm indoors
Growth Rate Moderate
Growth Pattern Catnip grows upright with branching stems. It can become somewhat bushy if pruned regularly. It spreads moderately through seeds and can form clumps.

Ornamental Onion

Height 0.15-1.5 meters (depending on species)
Spread 0.15-0.6 meters (depending on species)
Growth Rate Moderate
Growth Pattern Ornamental onions grow from bulbs and produce upright stems topped with spherical flower heads. The foliage is typically basal and grass-like or strap-shaped. Some species spread slowly via bulb offsets, forming clumps over time.

🌱 Propagation — Comparing Plant Growth

Catnip

Methods: Seed, Stem cuttings, Division

Difficulty: Easy

Tips: For stem cuttings, take 4-6 inch cuttings from new growth, remove the lower leaves, and place in water or directly into moist soil. Keep the soil consistently moist until roots develop. Division is best done in spring or fall, separating the plant at the root ball.

Ornamental Onion

Methods: Bulb offsets, Seed

Difficulty: Moderate

Tips: Divide bulb offsets in the fall after the foliage has died back. Sow seeds in the spring or fall.

✨ Benefits & Features — Comparing Plant Value

Catnip

Catnip is known for its unique effect on cats, causing them to exhibit playful and excited behaviors. The active compound, nepetalactone, is responsible for this effect. It also has a distinct minty aroma.

  • ✓ Provides enrichment for cats
  • ✓ Can be used to make herbal tea
  • ✓ Attractive foliage and flowers
  • ✓ Relatively easy to grow
  • ✓ Attracts pollinators to the garden
  • ⚠️ Toxic to pets

Ornamental Onion

Ornamental onions are known for their striking, spherical flower heads that come in a variety of colors and sizes. They are also deer-resistant and attract pollinators, making them a valuable addition to any garden. Their foliage often dies back before flowering, adding to their unique appeal.

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

📅 Maintenance Schedule — Plant Care Comparison

Catnip

Repotting Repot every 1-2 years, or when the plant becomes root-bound.
Pruning Prune regularly to maintain shape and encourage bushier growth. Deadhead spent flowers to prevent self-seeding.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, applied every 4-6 weeks during the growing season (spring and summer).
Seasonal Care In winter, reduce watering and ensure the plant receives as much light as possible. In summer, water more frequently and provide some afternoon shade if temperatures are excessively high. Prune after flowering to encourage bushier growth.

Ornamental Onion

Repotting Not applicable for in-ground planting. For container-grown plants, repot every 2-3 years in the fall.
Pruning Remove spent flower heads to prevent self-seeding. Allow foliage to die back naturally before removing it.
Fertilizing Apply a balanced fertilizer (10-10-10) in early spring as new growth emerges. Avoid over-fertilizing, which can lead to excessive foliage growth at the expense of flowering.
Seasonal Care In spring, fertilize as new growth emerges. In summer, ensure adequate watering during dry periods. In fall, allow foliage to die back naturally and divide bulbs if needed. In winter, provide a dry, dormant period.

🌞 Light Requirements

Catnip

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

Low light tolerant: ❌ No

Ornamental Onion

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

Low light tolerant: ❌ No

💧 Watering Needs

Catnip

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 musty smell.

Ornamental Onion

Water thoroughly when the top inch of soil is dry during the growing season. Reduce watering after flowering and during dormancy. Overwatering can lead to bulb rot, especially in poorly draining soil. Underwatering can cause stunted growth and poor flowering.

🌡️ Temperature & Humidity

Catnip

Temperature: 18-24°C

Humidity: 40-60%

Ornamental Onion

Temperature: 10-24°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Catnip

Catnip

Nepeta cataria
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Cat owners looking to provide their feline friends with a stimulating and enjoyable plant, while being aware of the risks to other pets.

✅ Choose This Plant If...

  • You want to provide a natural stimulant for your cat
  • You enjoy growing herbs for teas and other uses
  • You have a sunny location suitable for growing herbs
  • You are looking for a low-maintenance plant
  • You appreciate the plant's aromatic foliage.

❌ Skip This Plant If...

  • You have dogs or horses that might ingest it
  • You don't have a sunny location
  • You are sensitive to strong scents.
📍 Ideal Location: Sunny windowsill or balcony.
🎨 Style: Cottage, Herb Garden, Naturalistic
🏠 Apartment Friendly: Yes
⚠️ Although catnip is famous for its effect on cats, it can cause mild gastrointestinal upset (vomiting, diarrhea) if ingested in large quantities. According to the ASPCA, it is toxic to dogs and horses, causing vomiting, diarrhea, and incoordination if ingested. All parts of the plant are potentially toxic.
Ornamental Onion

Ornamental Onion

Allium spp.
Care: Expert Time: 5 minutes weekly during the growing season. Beginner: No

Gardeners looking for striking, low-maintenance plants 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 to your yard.
  • You appreciate unique, architectural flower shapes.
  • You are looking for a low-maintenance perennial.
  • You have a sunny garden space with well-draining soil.

❌ Skip This Plant If...

  • You have pets that may ingest the plant.
  • You lack a sunny outdoor space.
  • You are looking for a plant that thrives indoors.
📍 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, are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, abdominal pain, loss of appetite, and anemia.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

🎯

Catnip is rated Moderate care level, while Ornamental Onion is Expert.

💡 Pro Tips For Comparing These Plants

Catnip Care Tips

Catnip is relatively easy to grow, but requires ample sunlight, especially when grown indoors. Overwatering should be avoided. It can become leggy if not pruned regularly. While it is known for its appeal to cats, it is toxic to dogs and horses.

  • Provide at least 6 hours of direct sunlight daily.
  • Water thoroughly when the top inch of soil is dry, but avoid overwatering.
  • Prune regularly to maintain shape and encourage bushier growth.
  • Fertilize every 4-6 weeks during the growing season with a balanced liquid fertilizer.
  • Protect from extreme temperatures and frost.
❄️ Winter: Reduce watering during the winter months as the plant's growth slows down. Ensure the plant receives as much light as possible, especially if grown indoors. Protect from frost if grown outdoors.
☀️ Summer: Water more frequently during the summer months, especially during hot and dry periods. Provide some afternoon shade if temperatures are excessively high. Prune after flowering to encourage bushier growth.

Ornamental Onion Care Tips

Ornamental onions are primarily outdoor plants that require full sun and well-draining soil. They are not well-suited for indoor cultivation due to their high light requirements and dormancy needs. Indoor growing is challenging due to providing sufficient light and managing the dormancy period.

  • Plant bulbs in well-draining soil to prevent rot.
  • Provide full sun for optimal flowering.
  • Allow foliage to die back naturally after flowering.
  • Divide bulbs every few years to prevent overcrowding.
  • Avoid overwatering, especially during dormancy.
❄️ Winter: Ornamental onions require a dry, dormant period in the winter. Allow the foliage to die back naturally and avoid overwatering. In colder climates, a layer of mulch can help protect the bulbs from freezing temperatures.
☀️ Summer: Ensure adequate watering during dry periods in the summer. Remove spent flower heads to prevent self-seeding. Provide support for taller varieties to prevent them from flopping over.

⚠️ Common Problems & Solutions — Plant Care Comparison

Catnip

Common Issues: Powdery mildew, Aphids, Root rot
Solutions: For powdery mildew, improve air circulation and apply a fungicide. Treat aphids with insecticidal soap or neem oil. Prevent root rot by ensuring well-draining soil and avoiding overwatering.

Ornamental 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

Catnip

What are the light requirements for Catnip?

Catnip requires a minimum of six hours of direct sunlight each day to thrive. Insufficient light can result in leggy growth and reduced flowering. A south-facing window is ideal for indoor Catnip, providing ample sunlight throughout the day. If natural light is limited, supplement with grow lights, positioning them about 6-12 inches above the plant. Rotate the plant regularly to ensure even light exposure on all sides. Monitor the leaves for signs of sunburn, such as scorched spots, if the light is too intense. Adjust placement or provide shade as needed. Adequate light is crucial for photosynthesis and overall plant health.

How do I care for Catnip?

Catnip thrives in well-draining soil and requires at least six hours of sunlight daily. Water thoroughly when the top inch of soil feels dry, but avoid overwatering to prevent root rot. Fertilize sparingly with a balanced, slow-release fertilizer in the spring to encourage healthy growth and blooming. Prune regularly to maintain a compact shape and promote bushier growth. Catnip is relatively low-maintenance but benefits from occasional deadheading to encourage further flowering. Protect from extreme cold during winter months, especially in colder climates. Indoor plants need good air circulation. Monitor for pests like aphids and spider mites, and treat promptly. Choose a pot with drainage holes.

How do I propagate Catnip?

Catnip can be easily propagated through stem cuttings, division, or seeds. For stem cuttings, take a 4-6 inch cutting from a healthy stem, remove the lower leaves, and place it in water or directly into moist soil. Roots should develop within a few weeks. For division, carefully dig up the plant and separate the root ball into smaller sections, ensuring each section has healthy roots and foliage. Replant the divisions in separate pots. Seeds can be sown directly into the garden or started indoors. Keep the soil moist until germination occurs. Propagation is best done in spring or early summer.

Ornamental Onion

What are the light requirements for Ornamental Onion?

Ornamental Onions require at least 6-8 hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient light can result in weak stems, fewer flowers, and overall poor growth. When grown indoors, place them near a south-facing window where they can receive maximum sunlight exposure. If natural light is limited, supplement with grow lights to ensure adequate illumination. Rotate the plant regularly to ensure even light distribution on all sides. Monitor the plant for signs of light stress, such as pale leaves or elongated stems, and adjust its position accordingly.

How do I care for Ornamental Onion?

Ornamental Onions thrive in well-draining soil and full sun. Plant bulbs in the fall for spring blooms, or in early spring for summer blooms. Water thoroughly after planting and then moderately throughout the growing season, allowing the soil to dry slightly between waterings. Fertilize in early spring with a balanced fertilizer to encourage strong growth and abundant blooms. Deadhead spent flowers to prevent seed production and encourage further blooming. In colder climates, provide winter protection by mulching around the base of the plant. Divide clumps every few years to prevent overcrowding and maintain vigor. With proper care, your Ornamental Onions will provide years of stunning floral displays. Maintain good airflow to prevent fungal diseases.

How do I propagate Ornamental Onion?

Ornamental Onions can be propagated by division, stem cuttings, or keiki (small plantlets that grow on the flower stalk).

Last updated: April 27, 2026 — Plant care data reviewed and verified by our editorial team.