Four O'Clock vs Hart's Tongue Fern Plant Comparison

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

Four O'Clock

Four O'Clock

Mirabilis jalapa

VS
Hart's Tongue Fern

Hart's Tongue Fern

Asplenium scolopendrium

Four O'Clock

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.

Nyctaginaceae Tropical South America
✨ Features: Flowers open in the late afternoon or early evening and emit a sweet fragrance; flowers come in a variety of colors and can even be multicolored on the same plant.
📖 Read Complete Four O'Clock Guide
Hart's Tongue Fern

Hart's Tongue Fern

Asplenium scolopendrium

Hart's Tongue Fern is an evergreen fern characterized by its simple, strap-shaped fronds. These fronds, resembling a deer's tongue, are glossy green and have a leathery texture. It's primarily an outdoor plant, thriving in cool, damp, shaded environments like woodlands and limestone cliffs. While it can be grown indoors, it requires specific conditions to mimic its natural habitat. People grow it for its unique foliage and architectural interest in shaded gardens or as a curiosity indoors.

Aspleniaceae Europe, eastern North America, and parts of Asia
✨ Features: Unique foliage, air purification (though not extensively studied)
📖 Read Complete Hart's Tongue Fern Guide

Quick Plant Comparison

Feature Four O'Clock Hart's Tongue Fern
Light Full sun to partial shade Partial to full shade. Avoid direct sunlight.
Watering Every 3-7 days depending on weather and soil drainage Every 5-7 days, depending on humidity and temperature
Humidity 40-60% 60-80%
Temperature 18-27°C 13-18°C
Care Level Expert Moderate
Growth Rate Fast Slow
Max Height 0.3-1 meter (indoors unlikely to reach this height) 30-60 cm
Pet Safety ❌ Toxic To Pets ✅ Safe
Soil Well-draining soil, such as a mix of garden soil, sand, and compost Well-draining, humus-rich soil. A mix of peat moss, perlite, and garden soil works well.
Beginner Friendly ❌ No With Caution
Weekly Maintenance 15 minutes weekly 10 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.

Hart's Tongue Fern

Scientific Name Asplenium scolopendrium
Family Aspleniaceae
Native To Europe, eastern North America, and parts of Asia
Also Known As Hart's Tongue Fern, Hart's-tongue Fern
Leaves The leaves, or fronds, are simple, undivided, and strap-shaped, typically 15-45 cm long and 3-6 cm wide. They are a glossy, bright green color with a leathery texture and have slightly wavy edges. The underside of the fronds features rows of sori (spore-producing structures).
Flowers Ferns do not flower. They reproduce via spores.

📏 Size & Growth — Plant Comparison

Four O'Clock

Height 0.3-1 meter (indoors unlikely to reach this height)
Spread 0.3-0.6 meters (can spread via tuberous roots)
Growth Rate Fast
Growth Pattern Bushy and upright, typically reaching 1-3 feet in height and spread. It grows from tuberous roots, which allow it to regrow each year in warmer climates.

Hart's Tongue Fern

Height 30-60 cm
Spread 30-45 cm
Growth Rate Slow
Growth Pattern It grows in a clumping habit, with fronds emerging from a central rhizome. It does not spread aggressively.

🌱 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.

Hart's Tongue Fern

Methods: Spores, Division

Difficulty: Moderate

Tips: Spores require a sterile environment and high humidity to germinate. Division is best done in spring, separating the rhizomes carefully.

✨ 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

Hart's Tongue Fern

The Hart's Tongue Fern is unique due to its undivided, strap-shaped fronds, which are unlike the typical divided fronds of most ferns. The sori are arranged in neat rows on the underside of the fronds, adding to its distinctive appearance.

  • ✓ Adds unique texture and visual interest to shaded areas.
  • ✓ Non-toxic to pets and children.
  • ✓ Can help improve humidity levels in a small area.
  • ✓ Offers a calming and natural aesthetic.
  • ✓ Relatively low-maintenance once established in the right conditions.
  • 🌬️ NASA-verified air purifier
  • 🐾 Pet Safe

📅 Maintenance Schedule — Plant Care Comparison

Four O'Clock

Repotting Not typically grown indoors. If grown in containers, repot annually in the spring, especially if root-bound.
Pruning Deadhead spent flowers to encourage more blooms. Prune back stems in late fall to prepare for winter dormancy.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season
Seasonal Care In colder climates, treat as an annual or dig up tubers in the fall and store them in a cool, dry place for replanting in the spring. Reduce watering in the winter.

Hart's Tongue Fern

Repotting Every 2-3 years, or when the plant becomes root-bound.
Pruning Remove any dead or damaged fronds at the base of the plant.
Fertilizing Liquid fern fertilizer diluted to half strength, every 4-6 weeks during the growing season (spring and summer).
Seasonal Care Reduce watering in winter as growth slows. Increase humidity during dry winter months. In summer, ensure adequate shade to prevent scorching.

🌞 Light Requirements

Four O'Clock

Full sun to partial shade

Low light tolerant: ❌ No

Hart's Tongue Fern

Partial to full shade. Avoid direct sunlight.

Low light tolerant: ✅ Yes

💧 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.

Hart's Tongue Fern

Keep the soil consistently moist but not waterlogged. Water when the top inch of soil feels slightly dry. Overwatering can lead to root rot, while underwatering will cause the fronds to brown and crisp.

🌡️ Temperature & Humidity

Four O'Clock

Temperature: 18-27°C

Humidity: 40-60%

Hart's Tongue Fern

Temperature: 13-18°C

Humidity: 60-80%

🤔 Which Plant Is Right For You?

Four O'Clock

Four O'Clock

Mirabilis jalapa
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners 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.
📍 Ideal Location: Outdoor garden, sunny border, or patio container
🎨 Style: Cottage, Bohemian, Traditional
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the seeds and roots, are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and abdominal pain. According to the ASPCA, it contains asparagine.
Hart's Tongue Fern

Hart's Tongue Fern

Asplenium scolopendrium
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Experienced plant enthusiasts who can provide the specific environmental conditions required for healthy growth.

✅ Choose This Plant If...

  • You appreciate unique foliage and architectural plants.
  • You have a shaded, humid environment in your home or garden.
  • You are willing to provide consistent moisture and humidity.
  • You enjoy a plant that adds a touch of woodland charm.
  • You are looking for a non-toxic plant for a home with pets.

❌ Skip This Plant If...

  • You have a dry indoor environment.
  • You tend to overwater plants.
  • You don't have a shaded location.
  • You are a beginner plant owner.
📍 Ideal Location: Bathroom, north-facing window, terrarium
🎨 Style: Woodland, Cottagecore, Naturalistic
🏠 Apartment Friendly: Limited
🌬️ Air Purifying: Yes (NASA verified)
⚠️ According to multiple sources, including the ASPCA, Asplenium species are generally considered non-toxic to dogs, cats, and horses. However, it's always best to prevent pets from consuming any plant material.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Hart's Tongue Fern ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

🎯

Four O'Clock is rated Expert care level, while Hart's Tongue Fern is Moderate.

📈

Four O'Clock has fast growth, while Hart's Tongue Fern grows slow.

💡 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.
❄️ Winter: In colder climates, dig up the tubers and store them in a cool, dry place over the winter. Alternatively, treat as an annual and replant in the spring.
☀️ Summer: Provide consistent moisture during the hot summer months. Deadhead spent flowers to encourage more blooms. Monitor for pests and diseases.

Hart's Tongue Fern Care Tips

Hart's Tongue Fern requires consistent moisture, high humidity, and shade. Indoor cultivation can be challenging due to the need for specific environmental conditions. Providing adequate humidity and avoiding direct sunlight are crucial for success.

  • Provide consistent moisture, but avoid soggy soil.
  • Increase humidity by misting regularly or using a humidifier.
  • Avoid direct sunlight, which can scorch the fronds.
  • Use a well-draining potting mix rich in organic matter.
  • Fertilize sparingly during the growing season.
❄️ Winter: Reduce watering frequency as growth slows. Ensure adequate humidity, as indoor heating can dry out the air. Avoid placing near heat sources.
☀️ Summer: Provide adequate shade to prevent scorching. Increase watering frequency if the soil dries out quickly. Ensure good air circulation to prevent fungal diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Four O'Clock

Common Issues: Powdery mildew, Aphids, Root rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap. Root rot: Ensure well-draining soil and avoid overwatering.

Hart's Tongue Fern

Common Issues: Brown fronds, Root rot, Scale insects, Snail/slug damage
Solutions: Brown fronds: Increase humidity and ensure consistent watering. Root rot: Improve drainage and reduce watering frequency. Scale insects: Treat with insecticidal soap. Snail/slug damage: Use snail bait or handpick them off the plant.

❓ 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.

Hart's Tongue Fern

What are the light requirements for Hart's Tongue Fern?

Hart’s Tongue Fern thrives in bright, indirect light. Direct sunlight can scorch its delicate fronds, leading to brown spots and stunted growth. A north-facing window is often ideal, providing ample light without the harsh intensity. East-facing windows can also work well, as long as the morning sun is not too strong. Avoid placing the fern in direct south or west-facing windows unless you can provide significant shading. Insufficient light can result in pale, leggy growth and a loss of the vibrant green color. Regularly assess your fern’s light exposure and adjust its placement as needed to ensure optimal growth and health.

How do I care for Hart's Tongue Fern?

Hart’s Tongue Fern requires specific care to thrive. Provide bright, indirect light, avoiding direct sunlight which can scorch the fronds. Maintain consistently moist soil, but avoid overwatering which can lead to root rot. Water when the top inch of soil feels dry. High humidity is crucial; aim for 60-80% humidity. Use a well-draining potting mix rich in organic matter. Fertilize sparingly during the growing season (spring and summer) with a diluted liquid fertilizer. Keep temperatures between 60-70°F (15-21°C). Prune away any dead or damaged fronds to encourage new growth. Repot only when necessary, usually every 2-3 years. Protect from drafts and sudden temperature changes. Regular misting is beneficial.

How do I propagate Hart's Tongue Fern?

Hart’s Tongue Fern can be propagated through division or spores. For division, carefully separate the rhizome into sections, ensuring each section has healthy fronds and roots. Plant each section in its own pot with well-draining soil. To propagate from spores, collect spores from mature fronds. Sow the spores on a sterile growing medium and maintain high humidity. Germination can take several weeks. Division is the easier and more common method. Ensure each division has adequate roots before repotting. Provide high humidity and indirect light during the propagation process.

Last updated: April 19, 2026 — Plant care data reviewed and verified by our editorial team.