Butterfly Bush vs Flax Lily Plant Comparison

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

Butterfly Bush

Butterfly Bush

Buddleja davidii

VS
Flax Lily

Flax Lily

Dianella tasmanica

Butterfly Bush

Butterfly Bush

Buddleja davidii

Buddleja davidii, commonly known as Butterfly Bush, is a deciduous shrub known for its fragrant, nectar-rich flowers that attract butterflies and other pollinators. It typically grows to a height of 6-12 feet and a spread of 4-15 feet in its natural outdoor environment. It features arching branches and lance-shaped leaves. While highly desirable for its beauty and wildlife attraction, it is primarily an outdoor plant and presents significant challenges when grown indoors due to its need for intense sunlight and large size. People grow it for its beautiful flowers and to attract butterflies.

Scrophulariaceae China, Japan
✨ Features: Attracts butterflies and other pollinators.
📖 Read Complete Butterfly Bush Guide
Flax Lily

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.

Asphodelaceae Tasmania, Australia
✨ Features: Attractive foliage, clumping habit
📖 Read Complete Flax Lily Guide

Quick Plant Comparison

Feature Butterfly Bush Flax Lily
Light Full sun (at least 6-8 hours of direct sunlight daily) Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day.
Watering Outdoors: Once or twice a week during the growing season, less frequently in winter. Indoors (not recommended): Extremely difficult to maintain proper moisture levels. Every 1-2 weeks, depending on environmental conditions and pot size.
Humidity 30-50% 40-60%
Temperature 15-27°C 15-24°C
Care Level Expert Moderate
Growth Rate Fast Moderate
Max Height Indoors: Unlikely to thrive and reach full size; potentially 1-3 feet in a very large container with ideal conditions. Outdoors: 6-12 feet. 0.5-1 meter (indoors, typically smaller)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil; a mix of garden soil, sand, and compost is suitable. Well-draining potting mix with added perlite or sand.
Beginner Friendly ❌ No With Caution
Weekly Maintenance 30 minutes weekly (including watering, pruning, and pest control) 10 minutes weekly

🔬 Botanical Information — Comparing These Plants

Butterfly Bush

Scientific Name Buddleja davidii
Family Scrophulariaceae
Native To China, Japan
Also Known As Butterfly Bush, Summer Lilac
Leaves The leaves are lance-shaped, opposite, and typically 4-10 inches long. They are usually green or grayish-green and have a slightly rough texture.
Flowers Butterfly Bush produces long, cone-shaped flower clusters (panicles) at the ends of its branches. The flowers come in a variety of colors, including purple, pink, white, and yellow. Flowering occurs primarily in summer and fall. It is highly unlikely to flower indoors.

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.

📏 Size & Growth — Plant Comparison

Butterfly Bush

Height Indoors: Unlikely to thrive and reach full size; potentially 1-3 feet in a very large container with ideal conditions. Outdoors: 6-12 feet.
Spread Indoors: Limited by container size; potentially 1-3 feet. Outdoors: 4-15 feet.
Growth Rate Fast
Growth Pattern Butterfly Bush grows as a deciduous shrub with arching branches. It can become quite large if not pruned regularly, and its growth is vigorous, especially in full sun.

Flax Lily

Height 0.5-1 meter (indoors, typically smaller)
Spread 0.5-1 meter (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern It grows in a clumping habit, with leaves arching outwards from the base. It spreads via rhizomes, gradually expanding its footprint.

🌱 Propagation — Comparing Plant Growth

Butterfly Bush

Methods: Stem cuttings, Seed

Difficulty: Easy

Tips: Take softwood cuttings in spring or hardwood cuttings in late fall. Root in well-draining soil.

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.

✨ Benefits & Features — Comparing Plant Value

Butterfly Bush

Butterfly Bush is known for its ability to attract a wide variety of butterflies and other pollinators with its fragrant, nectar-rich flowers. Its fast growth rate and adaptability to various soil conditions make it a popular choice for gardeners.

  • ✓ Attracts butterflies and other pollinators
  • ✓ Provides beautiful, fragrant flowers
  • ✓ Adds visual interest to the garden
  • ✓ Supports local ecosystems
  • ✓ Can be used for cut flowers
  • ⚠️ Toxic to pets

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

📅 Maintenance Schedule — Plant Care Comparison

Butterfly Bush

Repotting Not applicable for indoor growing due to unsuitability. If attempted, repot annually in spring into a larger container.
Pruning Prune hard in early spring to remove dead or weak wood and to shape the plant. Deadhead spent flowers to encourage continued blooming.
Fertilizing Balanced fertilizer (10-10-10) in spring and early summer. Dilute to half strength.
Seasonal Care Prune hard in early spring to encourage new growth and flowering. Reduce watering in winter. Provide winter protection in colder climates.

Flax Lily

Repotting Every 1-2 years, or when the plant becomes root-bound. Divide the rhizomes during repotting to control spread.
Pruning Remove dead or damaged leaves as needed. Trim back excessive growth to maintain shape.
Fertilizing Balanced liquid fertilizer diluted to half strength, every 2-3 months during the growing season (spring and summer).
Seasonal Care Reduce watering in winter when growth slows. Provide adequate light during shorter days. In summer, ensure adequate moisture and protect from intense direct sunlight.

🌞 Light Requirements

Butterfly Bush

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Flax Lily

Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day.

Low light tolerant: ❌ No

💧 Watering Needs

Butterfly Bush

Water deeply when the top inch of soil is dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting leaves and dry soil. Signs of overwatering include yellowing leaves and soggy soil.

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.

🌡️ Temperature & Humidity

Butterfly Bush

Temperature: 15-27°C

Humidity: 30-50%

Flax Lily

Temperature: 15-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Butterfly Bush

Butterfly Bush

Buddleja davidii
Care: Expert Time: 30 minutes weekly (including watering, pruning, and pest control) Beginner: No

Gardeners with outdoor space who want to attract butterflies and other pollinators.

✅ Choose This Plant If...

  • You want to attract butterflies and other pollinators to your garden.
  • You have a sunny outdoor space.
  • You enjoy fragrant flowers.
  • You are willing to prune regularly.
  • You want a fast-growing shrub.

❌ Skip This Plant If...

  • You have limited outdoor space.
  • You are looking for an easy indoor plant.
  • You have pets that might ingest the plant.
  • You live in an area where it is considered invasive.
📍 Ideal Location: Outdoor garden or sunny patio.
🎨 Style: Cottage, Naturalistic, Wildlife Garden
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Butterfly Bush is toxic to dogs, cats, and horses. Symptoms include vomiting and diarrhea. All parts of the plant are considered toxic.
Flax Lily

Flax Lily

Dianella tasmanica
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Someone 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.
📍 Ideal Location: Bright bathroom, living room near a window with filtered light, or a covered patio.
🎨 Style: Modern, Tropical, Bohemian
🏠 Apartment Friendly: Yes
⚠️ According to the ASPCA, Dianella species are toxic to dogs, cats, and horses. The toxic principle is not explicitly stated, but symptoms include vomiting and diarrhea.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Flax Lily

⚡ Key Differences Between These Plants

🎯

Butterfly Bush is rated Expert care level, while Flax Lily is Moderate.

📈

Butterfly Bush has fast growth, while Flax Lily grows moderate.

💡 Pro Tips For Comparing These Plants

Butterfly Bush Care Tips

Butterfly Bush is primarily an outdoor plant and is very difficult to grow indoors due to its high light requirements and potential size. It needs full sun, well-draining soil, and regular pruning. Indoor cultivation is not recommended unless you can provide intense supplemental lighting and a very large container.

  • Prune in early spring to encourage new growth.
  • Deadhead spent flowers to prolong blooming.
  • Provide well-draining soil to prevent root rot.
  • Fertilize in spring and early summer.
  • Monitor for pests and diseases regularly.
❄️ Winter: In colder climates, provide winter protection by mulching around the base of the plant. Reduce watering during dormancy. Pruning should be done in early spring, not in the fall or winter.
☀️ Summer: Provide regular watering during hot, dry periods. Deadhead spent flowers to encourage continued blooming. Monitor for pests and diseases.

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.
❄️ Winter: Reduce watering frequency during winter as growth slows down. Ensure the plant still receives adequate light. Avoid placing it near cold drafts.
☀️ Summer: Provide adequate moisture during the warmer months. Protect from intense direct sunlight to prevent leaf burn. Increase humidity if possible.

⚠️ Common Problems & Solutions — Plant Care Comparison

Butterfly Bush

Common Issues: Spider mites, Aphids, Root rot, Powdery mildew
Solutions: Spider mites/Aphids: Insecticidal soap or neem oil. Root rot: Improve drainage, reduce watering. Powdery mildew: Fungicide, improve air circulation.

Flax Lily

Common Issues: Root rot, brown leaf tips, spider mites
Solutions: Root rot: Ensure proper drainage and avoid overwatering. Treat with fungicide if necessary.|Brown leaf tips: Increase humidity or water more consistently. Avoid letting the soil dry out completely.|Spider mites: Treat with insecticidal soap or neem oil.

❓ Frequently Asked Questions — Comparing These Plants

Butterfly Bush

What are the light requirements for Butterfly Bush?

Butterfly Bush requires a minimum of 6 hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient sunlight can lead to leggy growth, reduced flowering, and pale foliage. Choose a planting location that receives full sun throughout the day. In hotter climates, some afternoon shade may be beneficial to prevent scorching of the leaves.

How do I care for Butterfly Bush?

Butterfly Bush thrives in full sun, requiring at least 6 hours of direct sunlight daily for optimal blooming. Plant in well-draining soil with a slightly acidic to neutral pH. Water deeply but infrequently, allowing the soil to dry out slightly between waterings to prevent root rot. Fertilize in early spring with a balanced fertilizer to promote healthy growth and abundant flowers.

How do I propagate Butterfly Bush?

Butterfly Bush can be propagated through stem cuttings, division, and, less commonly, from seed. For stem cuttings, take 4-6 inch cuttings from new growth in late spring or early summer. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix and keep them moist until roots develop, usually within a few weeks.

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.

Last updated: May 9, 2026 — Plant care data reviewed and verified by our editorial team.