Bells of Ireland vs Kohlrabi Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Bells of Ireland
Moluccella laevis
Bells of Ireland is an annual flowering plant known for its tall spikes of vibrant green, bell-shaped calyces (modified leaves) that surround tiny, inconspicuous white flowers. It typically grows to a height of 2-3 feet. While it can be grown indoors, it's primarily an outdoor plant, often cultivated in gardens for its unique architectural form and long-lasting cut flowers. People grow it for its ornamental value, particularly in floral arrangements, where its bright green color adds a striking contrast.
Kohlrabi
Brassica oleracea var. gongylodes
Kohlrabi is a biennial vegetable cultivated as an annual, known for its swollen, globular stem that grows above ground. It features a crisp, mild flavor similar to a turnip or cabbage. The plant has long-stalked leaves emerging from the bulbous stem. It is primarily grown outdoors in gardens and farms for its edible stem and leaves. While it can be started indoors, it requires full sun and ample space to thrive, making it challenging to grow to maturity indoors. People grow kohlrabi for its unique texture and flavor in salads, stir-fries, and other culinary applications.
Quick Plant Comparison
| Feature | Bells of Ireland | Kohlrabi |
|---|---|---|
| Light | Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily. | Full sun (at least 6 hours of direct sunlight daily) |
| Watering | Outdoors: 2-3 times per week, depending on weather. Indoors: Every 5-7 days, depending on light and humidity. | Every 2-3 days outdoors, depending on weather conditions |
| Humidity | 40-60% | 40-60% |
| Temperature | 15-24°C | 15-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | Indoors: 0.6-1 meter (2-3 feet). Outdoors: 0.6-1 meter (2-3 feet) | 30-45 cm (outdoors) |
| Pet Safety | ✅ Safe | ✅ Safe |
| Soil | Well-draining potting mix or garden soil. A mix of potting soil, perlite, and vermiculite is suitable. | Well-draining, fertile soil rich in organic matter |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly | 15-30 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Bells of Ireland
| Scientific Name | Moluccella laevis |
|---|---|
| Family | Lamiaceae (Mint family) |
| Native To | Western Asia (Turkey, Syria, Caucasus) |
| Also Known As | Bells of Ireland, Molucca Balm, Shellflower |
| Leaves | The leaves are light green, oval to rounded in shape, and have slightly toothed edges. They are arranged oppositely along the stem and are generally inconspicuous compared to the prominent calyces. |
| Flowers | The actual flowers are small, white, and relatively insignificant, hidden within the larger green calyces. Flowering typically occurs in summer. |
Kohlrabi
| Scientific Name | Brassica oleracea var. gongylodes |
|---|---|
| Family | Brassicaceae |
| Native To | Northern Europe |
| Also Known As | German turnip, turnip cabbage |
| Leaves | The leaves of kohlrabi are typically bluish-green, broad, and have a slightly waxy texture. They are attached to the stem by long, slender stalks. The leaf shape can vary, but they are generally oval or rounded with slightly serrated edges. |
| Flowers | Kohlrabi will flower in its second year if allowed to overwinter. The flowers are typical of the Brassica family, with four petals arranged in a cross shape, usually yellow or white. Flowering is rare when grown as an annual for its bulb. |
📏 Size & Growth — Plant Comparison
Bells of Ireland
Kohlrabi
🌱 Propagation — Comparing Plant Growth
Bells of Ireland
Methods: Seed
Difficulty: Moderate
Tips: Sow seeds indoors 6-8 weeks before the last frost or directly outdoors after the last frost. Seeds require light to germinate, so press them gently into the soil surface. Keep the soil consistently moist.
Kohlrabi
Methods: Seed
Difficulty: Easy
Tips: Start seeds indoors 4-6 weeks before the last frost or direct sow outdoors after the last frost. Keep soil consistently moist.
✨ Benefits & Features — Comparing Plant Value
Bells of Ireland
The most striking feature is the bright green, bell-shaped calyces that surround the tiny white flowers. These calyces persist long after the flowers have faded, providing extended ornamental value. It is not native to Ireland, despite its common name.
- ✓ Adds unique architectural interest to gardens and floral arrangements.
- ✓ Provides a vibrant green color that contrasts well with other flowers.
- ✓ Attracts pollinators like bees and butterflies.
- ✓ Symbolizes luck and good fortune.
- ✓ Can be dried and used in dried flower arrangements.
- 🐾 Pet Safe
Kohlrabi
Kohlrabi is unique due to its edible, swollen stem that grows above ground, unlike root vegetables. Its mild flavor and crisp texture make it a versatile ingredient in various dishes. The plant also offers edible leaves, adding to its appeal.
- ✓ Provides fresh, nutritious vegetables
- ✓ Adds visual interest to the garden
- ✓ Encourages healthy eating habits
- ✓ Offers a unique culinary ingredient
- ✓ Supports sustainable living
- 🐾 Pet Safe
📅 Maintenance Schedule — Plant Care Comparison
Bells of Ireland
Kohlrabi
🌞 Light Requirements
Bells of Ireland
Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily.
Low light tolerant: ❌ No
Kohlrabi
Full sun (at least 6 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Bells of Ireland
Outdoors: Water regularly, keeping the soil consistently moist but not waterlogged. Indoors: Water thoroughly when the top inch of soil feels dry. Overwatering can lead to root rot; underwatering will cause wilting and browning of the calyces.
Kohlrabi
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to rot. Consistent moisture is important for bulb development. Signs of underwatering include wilting leaves and stunted growth. Overwatering can cause yellowing leaves and a mushy stem.
🌡️ Temperature & Humidity
Bells of Ireland
Temperature: 15-24°C
Humidity: 40-60%
Kohlrabi
Temperature: 15-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Bells of Ireland
Moluccella laevisExperienced gardeners who want a unique and striking addition to their cut flower arrangements.
✅ Choose This Plant If...
- You want a unique and striking addition to your garden or floral arrangements.
- You enjoy the challenge of growing plants that require specific conditions.
- You are looking for a plant with a strong architectural presence.
- You want to attract pollinators to your garden.
- You need a long-lasting cut flower with a vibrant green color.
❌ Skip This Plant If...
- You have limited sunlight indoors and cannot provide supplemental lighting.
- You are a beginner gardener looking for an easy-to-grow plant.
- You live in a very hot or humid climate, which can increase the risk of fungal diseases.
Kohlrabi
Brassica oleracea var. gongylodesGardeners looking for a unique and nutritious vegetable to grow outdoors.
✅ Choose This Plant If...
- You have a sunny garden space.
- You enjoy growing your own vegetables.
- You want a unique and nutritious addition to your diet.
- You are looking for a relatively fast-growing crop.
- You enjoy the taste of cabbage and turnips.
❌ Skip This Plant If...
- You lack sufficient outdoor space.
- You cannot provide at least 6 hours of direct sunlight daily.
- You are looking for a low-maintenance indoor plant.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Bells of Ireland has fast growth, while Kohlrabi grows moderate.
💡 Pro Tips For Comparing These Plants
Bells of Ireland Care Tips
Bells of Ireland are best suited for outdoor gardens. Growing them indoors is challenging due to their high light requirements. Supplemental lighting is almost always necessary. Consistent watering and well-draining soil are crucial to prevent root rot. Requires careful monitoring for pests and diseases.
- Start seeds indoors 6-8 weeks before the last frost for earlier blooms.
- Provide well-draining soil to prevent root rot.
- Water regularly, especially during hot and dry weather.
- Fertilize every 2-4 weeks during the growing season with a balanced liquid fertilizer.
- Pinch back young plants to encourage bushier growth.
Kohlrabi Care Tips
Kohlrabi is primarily an outdoor plant that requires full sun and consistent moisture. Growing it indoors is challenging due to the high light requirements and space needed for bulb development. It's best suited for experienced gardeners with outdoor space.
- Start seeds indoors for an earlier harvest.
- Ensure well-draining soil to prevent rot.
- Provide consistent moisture for optimal bulb development.
- Fertilize regularly during the growing season.
- Protect from pests like aphids and cabbage worms.
⚠️ Common Problems & Solutions — Plant Care Comparison
Bells of Ireland
Kohlrabi
❓ Frequently Asked Questions — Comparing These Plants
Bells of Ireland
What are the light requirements for Bells of Ireland?
Bells of Ireland crave sunlight. They need at least 6-8 hours of direct sunlight each day to produce vibrant green calyces and strong stems. Insufficient light can lead to leggy growth, pale coloring, and reduced blooming. When grown indoors, place them near a south-facing window where they can receive ample sunlight. If natural light is limited, supplement with grow lights. Rotate the plants regularly to ensure even light exposure on all sides. When starting seeds indoors, use grow lights to ensure healthy seedling development.
How do I care for Bells of Ireland?
Bells of Ireland require full sun, at least 6-8 hours daily, to thrive. Plant them in well-draining soil with a slightly acidic to neutral pH (6.0-7.0). Water regularly, keeping the soil consistently moist but not waterlogged, especially during hot weather. Fertilize every 2-3 weeks with a balanced liquid fertilizer during the growing season (spring and summer).
How do I propagate Bells of Ireland?
Bells of Ireland are typically propagated by seed.
Kohlrabi
What are the light requirements for Kohlrabi?
Kohlrabi thrives in full sun, requiring at least 6 hours of direct sunlight per day to produce healthy bulbs. Insufficient light can lead to leggy growth and smaller, less flavorful bulbs. In hotter climates, providing some afternoon shade can prevent the plant from bolting (prematurely going to seed). When growing indoors, place Kohlrabi near a south-facing window or use grow lights to supplement natural light. Rotate the plants regularly to ensure even light exposure on all sides. Monitor the leaves for signs of insufficient light, such as pale color or elongated stems, and adjust the light accordingly.
How do I care for Kohlrabi?
Kohlrabi requires well-draining soil rich in organic matter. Plant seeds directly in the garden or start indoors 4-6 weeks before the last frost. Space plants 6-8 inches apart in rows 12-18 inches apart. Water regularly, keeping the soil consistently moist but not waterlogged. Fertilize every 2-3 weeks with a balanced fertilizer, paying attention to potassium levels to promote strong bulb development. Kohlrabi prefers full sun but can tolerate partial shade, especially in warmer climates. Harvest when the bulb reaches 2-3 inches in diameter for the best flavor and texture. Protect from pests like cabbage worms and aphids with appropriate organic pest control methods. Rotate crops annually to prevent soilborne diseases.
How do I propagate Kohlrabi?
Kohlrabi is typically propagated by seed, but it is possible to propagate it through vegetative methods, although less common.
Last updated: April 27, 2026 — Plant care data reviewed and verified by our editorial team.