Boston Fern vs Kohlrabi Plant Comparison

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

Boston Fern

Boston Fern

Nephrolepis exaltata

VS
Kohlrabi

Kohlrabi

Brassica oleracea var. gongylodes

Boston Fern

Boston Fern

Nephrolepis exaltata

The Boston Fern is a classic houseplant known for its graceful, arching fronds. It's a terrestrial fern, naturally found in humid forests and swamps. Its lush green foliage creates a soft, textured appearance, making it a popular choice for adding a touch of nature to indoor spaces. People grow it for its aesthetic appeal, air-purifying qualities (though not definitively proven by NASA), and relatively easy care, provided its humidity needs are met. It is primarily an outdoor plant but can adapt to indoor conditions with proper care.

Nephrolepidaceae Tropical regions worldwide, particularly the Americas
✨ Features: Air purifying (though not definitively proven by NASA), adds a lush, tropical feel to indoor spaces
📖 Read Complete Boston Fern Guide
Kohlrabi

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.

Brassicaceae Northern Europe
✨ Features: Edible stem and leaves, high in vitamins and fiber
📖 Read Complete Kohlrabi Guide

Quick Plant Comparison

Feature Boston Fern Kohlrabi
Light Bright, indirect light. Avoid direct sunlight, which can scorch the fronds. Full sun (at least 6 hours of direct sunlight daily)
Watering Every 2-5 days, depending on humidity and light levels Every 2-3 days outdoors, depending on weather conditions
Humidity 60-80% 40-60%
Temperature 18-24°C 15-24°C
Care Level Moderate Expert
Growth Rate Moderate Moderate
Max Height 0.3-1 meter (indoors) 30-45 cm (outdoors)
Pet Safety ✅ Safe ✅ Safe
Soil Well-draining potting mix rich in organic matter, such as peat moss or coco coir Well-draining, fertile soil rich in organic matter
Beginner Friendly With Caution ❌ No
Weekly Maintenance 10-15 minutes weekly 15-30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Boston Fern

Scientific Name Nephrolepis exaltata
Family Nephrolepidaceae
Native To Tropical regions worldwide, particularly the Americas
Also Known As Boston Fern, Sword Fern
Leaves The leaves, or fronds, are pinnately compound, meaning they are composed of many small leaflets (pinnae) arranged along a central stem. The pinnae are typically bright green, lance-shaped, and have slightly serrated edges. The texture is delicate and feathery.
Flowers Boston Ferns do not flower indoors. They reproduce via spores, which are located on the underside of the fronds.

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

Boston Fern

Height 0.3-1 meter (indoors)
Spread 0.3-1 meter
Growth Rate Moderate
Growth Pattern The Boston Fern grows in a clumping, arching habit. New fronds emerge from the center of the plant, gradually unfurling and cascading outwards.

Kohlrabi

Height 30-45 cm (outdoors)
Spread 30-45 cm (outdoors)
Growth Rate Moderate
Growth Pattern Kohlrabi grows upright with a globular, swollen stem that forms above the soil surface. Leaves emerge from the stem on long stalks, creating a distinctive appearance. The plant does not spread aggressively.

🌱 Propagation — Comparing Plant Growth

Boston Fern

Methods: Division, Spores

Difficulty: Moderate

Tips: Divide the plant at the root ball, ensuring each division has healthy fronds and roots. Propagating from spores is more challenging and requires a sterile environment.

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

Boston Fern

Boston Ferns are known for their long, arching fronds that create a cascading effect. They require higher humidity than many other common houseplants, making them a bit more challenging to care for indoors.

  • ✓ Adds a touch of nature and elegance to indoor spaces.
  • ✓ Creates a relaxing and calming atmosphere.
  • ✓ Can help to improve indoor air quality (though not definitively proven).
  • ✓ Provides a sense of accomplishment when successfully cared for.
  • ✓ Offers a visually appealing texture and color contrast to other houseplants.
  • 🌬️ NASA-verified air purifier
  • 🐾 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

Boston Fern

Repotting Every 1-2 years, or when the plant becomes root-bound
Pruning Remove dead or yellowing fronds to maintain appearance and encourage new growth.
Fertilizing Balanced liquid fertilizer (20-20-20) diluted to half strength, every 4-6 weeks during the growing season (spring and summer)
Seasonal Care In winter, reduce watering frequency as growth slows. Maintain humidity levels. In summer, increase watering and consider moving the plant to a more humid location.

Kohlrabi

Repotting Not applicable, as it's typically grown as an annual.
Pruning Remove yellowing or damaged leaves to encourage growth.
Fertilizing Balanced fertilizer (10-10-10) every 4-6 weeks during the growing season
Seasonal Care Spring/Summer: Plant after the last frost, provide consistent moisture and fertilizer. Fall: Harvest before the first frost.

🌞 Light Requirements

Boston Fern

Bright, indirect light. Avoid direct sunlight, which can scorch the fronds.

Low light tolerant: ❌ No

Kohlrabi

Full sun (at least 6 hours of direct sunlight daily)

Low light tolerant: ❌ No

💧 Watering Needs

Boston Fern

Keep the soil consistently moist but not soggy. Water when the top inch of soil feels dry to the touch. Overwatering can lead to root rot, indicated by yellowing or browning fronds. Underwatering results in crispy, dry fronds.

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

Boston Fern

Temperature: 18-24°C

Humidity: 60-80%

Kohlrabi

Temperature: 15-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Boston Fern

Boston Fern

Nephrolepis exaltata
Care: Moderate Time: 10-15 minutes weekly Beginner: With-caution

Individuals who can provide consistent moisture and high humidity, such as those with humidifiers or bathrooms with natural light.

✅ Choose This Plant If...

  • You want a classic, elegant houseplant that adds a touch of greenery to your home.
  • You are looking for a plant that is non-toxic to pets.
  • You can provide the high humidity levels this plant needs to thrive.
  • You have a bright, indirectly lit space where the fern can flourish.
  • You enjoy the challenge of providing specific care requirements to keep a plant healthy.

❌ Skip This Plant If...

  • You struggle to maintain consistent watering schedules.
  • You live in a very dry climate and cannot provide adequate humidity.
  • You don't have a location with bright, indirect light.
📍 Ideal Location: Bathroom with natural light, bright kitchen, or any room with high humidity
🎨 Style: Traditional, Bohemian, Tropical
🏠 Apartment Friendly: Limited
🌬️ Air Purifying: Yes (NASA verified)
⚠️ According to the ASPCA, Boston Ferns are non-toxic to dogs, cats, and horses.
Kohlrabi

Kohlrabi

Brassica oleracea var. gongylodes
Care: Expert Time: 15-30 minutes weekly Beginner: No

Gardeners 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.
📍 Ideal Location: Outdoor garden or raised bed with full sun exposure
🎨 Style: Rustic, Cottage Garden
🏠 Apartment Friendly: No
⚠️ According to multiple sources, including the ASPCA, kohlrabi is not listed as toxic to dogs, cats, or horses. All parts of the plant are considered safe for consumption.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Both safe ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

🎯

Boston Fern is rated Moderate care level, while Kohlrabi is Expert.

💡 Pro Tips For Comparing These Plants

Boston Fern Care Tips

Boston Ferns require consistent moisture and high humidity to thrive indoors. Maintaining adequate humidity is the biggest challenge. They are not drought-tolerant and will suffer in dry environments. Provide bright, indirect light and regular fertilization during the growing season.

  • Mist the fronds regularly to increase humidity.
  • Place the pot on a pebble tray filled with water.
  • Use a humidifier to maintain consistent humidity levels.
  • Water thoroughly, allowing excess water to drain away.
  • Avoid placing the plant near drafts or heat sources.
❄️ Winter: Reduce watering frequency in winter as growth slows. Maintain humidity levels by misting or using a humidifier. Avoid placing the plant near cold drafts.
☀️ Summer: Increase watering frequency in summer as the plant actively grows. Provide shade from direct sunlight to prevent scorching. Consider moving the plant to a more humid location, such as a bathroom or shaded patio.

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.
❄️ Winter: Kohlrabi is typically harvested before winter. In milder climates, it may be possible to overwinter the plant with protection, but it's generally grown as an annual.
☀️ Summer: Provide consistent moisture during hot summer months. Protect from intense afternoon sun if necessary. Monitor for pests and diseases and take appropriate action.

⚠️ Common Problems & Solutions — Plant Care Comparison

Boston Fern

Common Issues: Browning fronds, Yellowing fronds, Pest infestations (spider mites, mealybugs), Root rot
Solutions: Browning fronds: Increase humidity. | Yellowing fronds: Adjust watering (avoid overwatering). | Pest infestations: Treat with insecticidal soap or neem oil. | Root rot: Repot in fresh soil and improve drainage.

Kohlrabi

Common Issues: Aphids, Cabbage worms, Clubroot
Solutions: Aphids: Insecticidal soap; Cabbage worms: Handpick or use Bacillus thuringiensis (Bt); Clubroot: Improve soil drainage and pH, use disease-resistant varieties.

❓ Frequently Asked Questions — Comparing These Plants

Boston Fern

What are the light requirements for Boston Fern?

Boston Ferns prefer bright, indirect light. Direct sunlight can scorch the delicate fronds, causing them to turn brown and crispy. An east-facing window is ideal, providing gentle morning sunlight. A north-facing window can also work, but the plant may not grow as vigorously. If placing the fern near a south- or west-facing window, be sure to filter the light with a sheer curtain. Insufficient light can lead to leggy growth and pale fronds. Rotate the plant regularly to ensure even light exposure on all sides. Artificial grow lights can supplement natural light, especially during the darker winter months.

How do I care for Boston Fern?

Boston Ferns thrive in bright, indirect light and high humidity. Water consistently, keeping the soil evenly moist but not soggy. Check the soil moisture regularly and water when the top inch feels slightly dry. Mist the fronds frequently or place the plant on a pebble tray filled with water to increase humidity. Fertilize monthly during the growing season (spring and summer) with a diluted liquid fertilizer formulated for ferns. Avoid placing the plant in direct sunlight or near drafts, as these can cause the fronds to dry out and turn brown. Repot every 1-2 years in the spring, using a well-draining potting mix. Regularly remove any dead or yellowing fronds to encourage new growth and maintain the plant’s appearance. Monitor for pests such as spider mites and treat as needed.

How do I propagate Boston Fern?

Boston Ferns can be propagated by division or by spores. Division is the easier method. To divide, carefully remove the plant from its pot and gently separate the root ball into two or more sections, ensuring each section has healthy fronds and roots. Repot each section in fresh potting mix. Propagation by spores is more challenging. Collect spores from the underside of mature fronds and sow them on a moist, sterile potting mix. Cover with a clear plastic dome to maintain high humidity and keep in indirect light. Spores can take several weeks or months to germinate. Keep the soil consistently moist and provide adequate ventilation to prevent fungal growth.

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 15, 2026 — Plant care data reviewed and verified by our editorial team.