Flax Lily vs Kohlrabi Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Flax Lily
Dianella tasmanica
Dianella tasmanica, commonly known as the Flax Lily, is a rhizomatous perennial herb native to Tasmania. It features strappy, arching leaves that resemble flax, hence the name. It typically grows outdoors in shaded or partially shaded areas. While it can be grown indoors, it requires specific conditions to thrive and may not flower as readily as when grown outdoors. People grow it for its attractive foliage, clumping habit, and relatively low maintenance when grown in suitable conditions.
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 | Flax Lily | Kohlrabi |
|---|---|---|
| Light | Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day. | Full sun (at least 6 hours of direct sunlight daily) |
| Watering | Every 1-2 weeks, depending on environmental conditions and pot size. | Every 2-3 days outdoors, depending on weather conditions |
| Humidity | 40-60% | 40-60% |
| Temperature | 15-24°C | 15-24°C |
| Care Level | Moderate | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | 0.5-1 meter (indoors, typically smaller) | 30-45 cm (outdoors) |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining potting mix with added perlite or sand. | Well-draining, fertile soil rich in organic matter |
| Beginner Friendly | With Caution | ❌ No |
| Weekly Maintenance | 10 minutes weekly | 15-30 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Flax Lily
| Scientific Name | Dianella tasmanica |
|---|---|
| Family | Asphodelaceae |
| Native To | Tasmania, Australia |
| Also Known As | Flax Lily, Tasman Flax Lily |
| Leaves | The leaves are long, linear, and strap-like, typically 30-90 cm long and 1-3 cm wide. They are usually green, but some cultivars have variegated foliage with stripes of yellow or white. The texture is smooth and slightly glossy. |
| Flowers | It may flower indoors, but it is more common when grown outdoors. The flowers are small, star-shaped, and blue or purple, followed by blue or purple berries. |
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
Flax Lily
Kohlrabi
🌱 Propagation — Comparing Plant Growth
Flax Lily
Methods: Division, Seed
Difficulty: Easy
Tips: Divide rhizomes in spring or early summer. Ensure each division has healthy roots and leaves. Sow seeds in spring after soaking them in warm water for 24 hours.
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
Flax Lily
Its strappy, arching leaves give it a unique texture and appearance. It spreads via rhizomes, forming clumps over time. While it can be grown indoors, it is primarily an outdoor plant.
- ✓ Adds a touch of greenery to indoor spaces.
- ✓ Relatively low maintenance.
- ✓ Can be easily propagated.
- ✓ Provides a calming, natural aesthetic.
- ✓ Tolerates some neglect.
- ⚠️ Toxic to pets
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
Flax Lily
Kohlrabi
🌞 Light Requirements
Flax Lily
Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day.
Low light tolerant: ❌ No
Kohlrabi
Full sun (at least 6 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Flax Lily
Water thoroughly when the top inch of soil feels dry to the touch. Ensure good drainage to prevent root rot. Overwatering can lead to yellowing leaves and root rot, while underwatering can cause the leaves to droop and brown at the tips.
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
Flax Lily
Temperature: 15-24°C
Humidity: 40-60%
Kohlrabi
Temperature: 15-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Flax Lily
Dianella tasmanicaSomeone looking for a low-maintenance plant with attractive foliage, but who is aware of its toxicity to pets.
✅ Choose This Plant If...
- You want a plant with attractive, grass-like foliage.
- You have a location with bright, indirect light.
- You are looking for a relatively low-maintenance plant.
- You want a plant that can be easily propagated by division.
- You understand its toxicity to pets and can keep it out of their reach.
❌ Skip This Plant If...
- You have pets that may ingest plants.
- You have a very dark home with limited natural light.
- You are prone to overwatering plants.
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
Flax Lily is rated Moderate care level, while Kohlrabi is Expert.
💡 Pro Tips For Comparing These Plants
Flax Lily Care Tips
Flax Lily is relatively easy to care for, but requires bright, indirect light and well-draining soil. Overwatering is a common problem. It may not flower indoors as readily as outdoors. It spreads via rhizomes, so repotting may be needed more frequently than other houseplants.
- Allow the top inch of soil to dry out before watering.
- Provide bright, indirect light to maintain vibrant foliage.
- Fertilize sparingly during the growing season.
- Monitor for pests like spider mites and treat promptly.
- Repot every 1-2 years to prevent root-bound conditions.
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
Flax Lily
Kohlrabi
❓ Frequently Asked Questions — Comparing These Plants
Flax Lily
What are the light requirements for Flax Lily?
Flax Lily flourishes in bright, indirect light. Direct sunlight can scorch its leaves, so avoid placing it in south-facing windows without some form of shading. An east or west-facing window is ideal, where it can receive gentle morning or afternoon light. If your plant is in a lower-light environment, its growth may be slower, and the colors may appear less vibrant. Rotate your plant regularly to ensure even light exposure on all sides. Insufficient light can lead to leggy growth and faded foliage.
How do I care for Flax Lily?
Flax Lily thrives in bright, indirect light but can tolerate lower light conditions. Water when the top inch of soil feels dry, ensuring the pot has good drainage to prevent root rot. Maintain moderate humidity levels, especially during dry seasons, by misting the plant regularly or using a humidifier. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Repot every 1-2 years, or when the plant becomes root-bound, using a well-draining potting mix. Prune away any dead or yellowing leaves to maintain its appearance and health. Protect from frost and extreme temperatures. Proper watering, light, and humidity are key to a thriving Flax Lily.
How do I propagate Flax Lily?
Flax Lily can be propagated through division, stem cuttings, and air layering.
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 22, 2026 — Plant care data reviewed and verified by our editorial team.