Four O'Clock vs Perennial Flax 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.
Perennial Flax
Linum perenne
Perennial Flax (Linum perenne) is a herbaceous perennial known for its delicate, airy appearance and profuse display of sky-blue flowers. It typically grows to a height of 30-60 cm. The plant features slender stems and narrow, lance-shaped leaves. While primarily an outdoor plant, it is grown for its ornamental value in gardens and meadows, attracting pollinators. The flowers are short-lived, opening in the morning and closing by afternoon, but the plant produces a continuous succession of blooms throughout the flowering season. It is not naturally an indoor plant.
Quick Plant Comparison
| Feature | Four O'Clock | Perennial Flax |
|---|---|---|
| Light | Full sun to partial shade | Full sun |
| Watering | Every 3-7 days depending on weather and soil drainage | Every 7-10 days, depending on weather and soil drainage |
| Humidity | 40-60% | 30-50% |
| 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) | N/A (Outdoor plant, not suitable for indoor growing) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining soil, such as a mix of garden soil, sand, and compost | Well-draining, sandy or loamy soil |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 15 minutes weekly | 5 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. |
Perennial Flax
| Scientific Name | Linum perenne |
|---|---|
| Family | Linaceae |
| Native To | Europe, North Africa, Asia |
| Also Known As | Perennial Flax, Blue Flax, Flax |
| Leaves | Narrow, lance-shaped leaves, typically blue-green in color, arranged alternately along the stems. |
| Flowers | Flowers are typically sky-blue, about 2.5 cm in diameter, with five petals. They open in the morning and close by afternoon. Rarely flowers indoors. |
📏 Size & Growth — Plant Comparison
Four O'Clock
Perennial Flax
🌱 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.
Perennial Flax
Methods: Seed, Division
Difficulty: Easy
Tips: Sow seeds in spring or fall. Divide established plants in spring or fall. Ensure good drainage for successful propagation.
✨ 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
Perennial Flax
Perennial Flax is known for its delicate, blue flowers that open in the morning and close by afternoon. It is a relatively low-maintenance perennial that attracts pollinators and is drought-tolerant once established.
- ✓ Attracts pollinators like bees and butterflies.
- ✓ Adds a delicate, airy texture to the garden.
- ✓ Provides a long season of blue flowers.
- ✓ Drought-tolerant once established, reducing water needs.
- ✓ Relatively low-maintenance, freeing up gardening time.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Four O'Clock
Perennial Flax
🌞 Light Requirements
Four O'Clock
Full sun to partial shade
Low light tolerant: ❌ No
Perennial Flax
Full sun
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.
Perennial Flax
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Ensure good drainage. Signs of underwatering include wilting and yellowing leaves. Overwatering can cause root rot and fungal diseases.
🌡️ Temperature & Humidity
Four O'Clock
Temperature: 18-27°C
Humidity: 40-60%
Perennial Flax
Temperature: 15-24°C
Humidity: 30-50%
🤔 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.
Perennial Flax
Linum perenneGardeners looking for a low-maintenance, flowering perennial for sunny locations.
✅ Choose This Plant If...
- You want a low-maintenance perennial for a sunny garden.
- You want to attract pollinators to your garden.
- You appreciate delicate, blue flowers.
- You have well-draining soil.
- You live in a climate with mild winters.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You don't have a sunny outdoor space.
- You are looking for an easy indoor plant.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Four O'Clock needs full sun to partial shade, while Perennial Flax prefers full sun.
Four O'Clock has fast growth, while Perennial Flax 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.
Perennial Flax Care Tips
Perennial Flax is primarily an outdoor plant and is challenging to grow indoors due to its high light requirements. It needs full sun and well-draining soil. Indoor attempts often result in leggy growth and poor flowering. It is toxic to pets.
- Ensure well-draining soil to prevent root rot.
- Provide full sun for optimal flowering.
- Deadhead spent flowers regularly to encourage more blooms.
- Apply a balanced fertilizer in spring.
- Protect from excessive moisture in winter.
⚠️ Common Problems & Solutions — Plant Care Comparison
Four O'Clock
Perennial Flax
❓ 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.
Perennial Flax
What are the light requirements for Perennial Flax?
Perennial Flax requires a minimum of six hours of direct sunlight per day to thrive and produce abundant blooms. A south-facing location is ideal, but east or west-facing exposures can also work if they provide sufficient sunlight. Insufficient light can lead to leggy growth, reduced flowering, and pale foliage. If growing indoors, place the plant near a sunny window or supplement with artificial grow lights. Rotate the plant regularly to ensure even light exposure on all sides. When transplanting, choose a location that receives full sun throughout the day. Be mindful of shadows cast by trees or buildings, especially during the shorter days of winter.
How do I care for Perennial Flax?
Perennial Flax thrives in full sun and well-drained soil. Water deeply but infrequently, allowing the soil to dry out between waterings. Amend heavy clay soils with compost or other organic matter to improve drainage. Fertilize lightly in spring with a balanced fertilizer to encourage blooming. Deadhead spent flowers to promote continued flowering. Cut back the plant after blooming to maintain its shape and encourage bushier growth. Provide support if necessary, as the stems can become leggy. Protect from excessive winter moisture in colder climates. Mulch around the base of the plant to retain moisture and suppress weeds. Monitor for pests and diseases, and treat promptly if necessary. Divide established plants every few years to rejuvenate them.
How do I propagate Perennial Flax?
Perennial Flax can be propagated by seed, division, or stem cuttings.
Last updated: May 6, 2026 — Plant care data reviewed and verified by our editorial team.