Four O'Clock vs Kohlrabi Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Four O'Clock
Mirabilis jalapa
Mirabilis jalapa, commonly known as the Four O'Clock flower, is a bushy, herbaceous perennial typically grown as an annual in cooler climates. It's known for its trumpet-shaped flowers that open in the late afternoon or early evening, releasing a sweet fragrance. The flowers come in a variety of colors, including pink, red, yellow, white, and multicolored variations. It grows from tuberous roots and can reach a height of 1-3 feet. It is primarily grown outdoors in gardens and borders for its vibrant colors and evening fragrance. It is not ideally suited as an indoor plant.
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 | Four O'Clock | Kohlrabi |
|---|---|---|
| Light | Full sun to partial shade | Full sun (at least 6 hours of direct sunlight daily) |
| Watering | Every 3-7 days depending on weather and soil drainage | Every 2-3 days outdoors, depending on weather conditions |
| Humidity | 40-60% | 40-60% |
| Temperature | 18-27°C | 15-24°C |
| Care Level | Expert | Expert |
| Growth Rate | Fast | Moderate |
| Max Height | 0.3-1 meter (indoors unlikely to reach this height) | 30-45 cm (outdoors) |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining soil, such as a mix of garden soil, sand, and compost | Well-draining, fertile soil rich in organic matter |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 15 minutes weekly | 15-30 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Four O'Clock
| Scientific Name | Mirabilis jalapa |
|---|---|
| Family | Nyctaginaceae |
| Native To | Tropical South America |
| Also Known As | Four O'Clock Flower, Marvel of Peru, Beauty-of-the-Night |
| Leaves | The leaves are ovate to lance-shaped, typically 2-4 inches long, and have a smooth texture. They are usually medium green in color and arranged oppositely along the stems. |
| Flowers | Flowers are trumpet-shaped, about 1-2 inches long, and come in a variety of colors including pink, red, yellow, white, and multicolored. They open in the late afternoon or early evening and emit a sweet fragrance. Flowering indoors is rare and unlikely. |
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
Four O'Clock
Kohlrabi
🌱 Propagation — Comparing Plant Growth
Four O'Clock
Methods: Seed, Tuber division
Difficulty: Easy
Tips: Sow seeds directly in the garden after the last frost or start them indoors 6-8 weeks before. Divide tubers in early spring.
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
Four O'Clock
The flowers open in the late afternoon or early evening, hence the name 'Four O'Clock'. They are known for their sweet fragrance and the ability to produce multiple colors on the same plant, sometimes even on the same flower.
- ✓ Adds vibrant color to the garden
- ✓ Provides a sweet evening fragrance
- ✓ Attracts pollinators
- ✓ Relatively low-maintenance once established
- ✓ Can self-seed and naturalize in suitable climates
- ⚠️ 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
Four O'Clock
Kohlrabi
🌞 Light Requirements
Four O'Clock
Full sun to partial shade
Low light tolerant: ❌ No
Kohlrabi
Full sun (at least 6 hours of direct sunlight daily)
Low light tolerant: ❌ No
💧 Watering Needs
Four O'Clock
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. During hot summer months, more frequent watering may be necessary. Reduce watering in cooler months.
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
Four O'Clock
Temperature: 18-27°C
Humidity: 40-60%
Kohlrabi
Temperature: 15-24°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Four O'Clock
Mirabilis jalapaGardeners looking for a fragrant, colorful addition to their evening garden.
✅ Choose This Plant If...
- You want a fragrant evening garden
- You enjoy vibrant, multicolored flowers
- You want a plant that attracts pollinators like moths and hummingbirds
- You are looking for a low-maintenance outdoor plant once established
- You want a plant that can self-seed and return year after year.
❌ Skip This Plant If...
- You have pets that may ingest the plant
- You lack a sunny outdoor space
- You want a plant that thrives indoors.
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
Four O'Clock needs full sun to partial shade, while Kohlrabi prefers full sun (at least 6 hours of direct sunlight daily).
Four O'Clock has fast growth, while Kohlrabi grows moderate.
💡 Pro Tips For Comparing These Plants
Four O'Clock Care Tips
Four O'Clocks are primarily outdoor plants and require full sun to thrive. Growing them indoors is challenging due to their high light requirements and potential for pest infestations. They also spread via tuberous roots, which can quickly outgrow a container. Indoor flowering is unlikely.
- Plant in well-draining soil to prevent root rot.
- Provide full sun for best flowering.
- Deadhead spent flowers regularly to encourage more blooms.
- Protect from strong winds, which can damage the delicate stems.
- Monitor for pests like aphids and treat promptly.
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
Four O'Clock
Kohlrabi
❓ Frequently Asked Questions — Comparing These Plants
Four O'Clock
What are the light requirements for Four O'Clock?
Four O’Clocks thrive in full sun, needing at least 6 hours of direct sunlight daily to produce abundant blooms. A sunny location encourages strong growth and vibrant flower colors. While they can tolerate partial shade, reduced sunlight will result in fewer flowers and leggier growth.
How do I care for Four O'Clock?
Four O’Clocks are relatively easy to care for. Plant them in well-draining soil in a location that receives at least 6 hours of sunlight daily for optimal blooming. Water regularly, especially during dry periods, but avoid overwatering, which can lead to root rot. Fertilize monthly during the growing season with a balanced fertilizer or one formulated for blooming plants to encourage abundant flowering.
How do I propagate Four O'Clock?
Four O’Clocks can be propagated through seeds, tubers, or stem cuttings.
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: May 6, 2026 — Plant care data reviewed and verified by our editorial team.