Comfrey vs Mountain Ash Plant Comparison

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

Comfrey

Comfrey

Symphytum officinale

VS
Mountain Ash

Mountain Ash

Sorbus aucuparia

Comfrey

Comfrey

Symphytum officinale

Comfrey is a perennial herb known for its historical use in traditional medicine, though its internal use is now discouraged due to toxicity concerns. It features coarse, hairy leaves and bell-shaped flowers that are typically purple, blue, pink, or white. It grows outdoors to a height of about 1-3 feet and spreads via rhizomes. People grow it for its attractive foliage and flowers, and historically for its medicinal properties (though this is now largely avoided). It is primarily an outdoor plant and does not thrive indoors.

Boraginaceae Europe and Asia
✨ Features: Historically used in herbal medicine (though now discouraged), attracts pollinators.
📖 Read Complete Comfrey Guide
Mountain Ash

Mountain Ash

Sorbus aucuparia

Sorbus aucuparia, commonly known as Rowan or European Mountain Ash, is a deciduous tree typically reaching 15-30 feet in height. It features pinnately compound leaves and clusters of white flowers in spring, followed by bright red-orange berries in the fall. While visually appealing, it's primarily an outdoor tree, thriving in full sun and well-drained soil. People grow it for its ornamental value, particularly the vibrant berries that attract birds. Indoor cultivation is extremely challenging due to its need for a cold dormancy period and intense sunlight.

Rosaceae Europe and parts of Asia
✨ Features: Attractive berries that provide food for birds, ornamental value in all seasons.
📖 Read Complete Mountain Ash Guide

Quick Plant Comparison

Feature Comfrey Mountain Ash
Light Full sun to partial shade Full sun (at least 6 hours of direct sunlight per day)
Watering Every 1-2 weeks, depending on weather and soil drainage Outdoors: Once or twice a week during the growing season, less frequently during dormancy. Indoors (not recommended): Extremely difficult to maintain proper moisture levels.
Humidity 30-50% 30-50%
Temperature 10-25°C 10-24°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height N/A - Not suitable for indoor growing Outdoors: 15-30 feet. Indoors: Not suitable for indoor growing.
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-drained soil, loamy or sandy soil is best. Tolerates a wide range of soil types, including poor soil. Well-drained, slightly acidic soil
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 10 minutes weekly (mostly weeding and watering) 30 minutes monthly (pruning, fertilizing, pest control)

🔬 Botanical Information — Comparing These Plants

Comfrey

Scientific Name Symphytum officinale
Family Boraginaceae
Native To Europe and Asia
Also Known As Comfrey, Common Comfrey, Knitbone, Boneset
Leaves The leaves are large, coarse, and hairy, with an oval to lanceolate shape. They are typically dark green and can grow up to 10 inches long. The texture is rough due to the presence of bristly hairs.
Flowers Comfrey produces bell-shaped flowers that hang in clusters. The flowers are typically purple, blue, pink, or white. It rarely flowers indoors.

Mountain Ash

Scientific Name Sorbus aucuparia
Family Rosaceae
Native To Europe and parts of Asia
Also Known As Rowan, European Mountain Ash
Leaves Pinnately compound leaves, typically 6-10 inches long, with 9-15 leaflets. Leaflets are lance-shaped, serrated, and dark green in color, turning reddish-purple in the fall.
Flowers It rarely, if ever, flowers indoors. Outdoors, it produces clusters of small, white flowers in the spring.

📏 Size & Growth — Plant Comparison

Comfrey

Height N/A - Not suitable for indoor growing
Spread N/A - Not suitable for indoor growing
Growth Rate Fast
Growth Pattern Comfrey grows as an upright, bushy perennial. It spreads aggressively via rhizomes, forming dense clumps.

Mountain Ash

Height Outdoors: 15-30 feet. Indoors: Not suitable for indoor growing.
Spread 10-20 feet
Growth Rate Moderate
Growth Pattern Upright, deciduous tree with a rounded crown. It typically grows as a single-trunk tree, but can sometimes have multiple stems.

🌱 Propagation — Comparing Plant Growth

Comfrey

Methods: Root cuttings, Division, Seed

Difficulty: Easy

Tips: Divide established plants in spring or fall. Root cuttings should be taken in late fall or early spring. Sow seeds directly in the garden in spring or fall.

Mountain Ash

Methods: Seed, cuttings, grafting

Difficulty: Moderate

Tips: For seed propagation, cold stratify seeds for several months before sowing. Cuttings should be taken in late spring or early summer.

✨ Benefits & Features — Comparing Plant Value

Comfrey

Comfrey is known for its rapid growth and ability to accumulate nutrients from the soil. It's also notable for its historical use in traditional medicine, although this is now largely discouraged due to toxicity concerns.

  • ✓ Attracts pollinators
  • ✓ Provides ground cover
  • ✓ Tolerates poor soil
  • ✓ Low maintenance
  • ✓ Historically used in herbal medicine
  • ⚠️ Toxic to pets

Mountain Ash

The bright red-orange berries are a key identifying feature and provide a valuable food source for birds in the fall and winter. Its tolerance for colder climates makes it suitable for northern regions.

  • ✓ Provides food and shelter for birds
  • ✓ Adds ornamental value to the landscape
  • ✓ Offers seasonal interest with flowers and berries
  • ✓ Can be used for traditional crafts and culinary purposes (with caution)
  • ✓ Provides shade in the summer
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Comfrey

Repotting N/A - Not suitable for indoor growing
Pruning Cut back foliage after flowering to encourage new growth. Remove any dead or damaged leaves.
Fertilizing Apply a balanced fertilizer (10-10-10) in early spring. Avoid over-fertilizing, as this can reduce flowering.
Seasonal Care In spring, apply fertilizer and divide plants if needed. In summer, water regularly and monitor for pests and diseases. In fall, cut back foliage after flowering. In winter, the plant will die back to the ground.

Mountain Ash

Repotting Not applicable for outdoor trees. Indoor attempts are unlikely to succeed.
Pruning Prune in late winter or early spring to remove dead or damaged branches and to shape the tree.
Fertilizing Balanced fertilizer (10-10-10) in spring, diluted to half strength. Avoid fertilizing during dormancy.
Seasonal Care Spring: Fertilize. Summer: Monitor for pests and water regularly. Fall: Berries ripen, prepare for dormancy. Winter: Dormancy period, minimal watering.

🌞 Light Requirements

Comfrey

Full sun to partial shade

Low light tolerant: ❌ No

Mountain Ash

Full sun (at least 6 hours of direct sunlight per day)

Low light tolerant: ❌ No

💧 Watering Needs

Comfrey

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Comfrey prefers consistently moist soil but doesn't like to sit in standing water. Signs of underwatering include wilting leaves; overwatering signs include yellowing leaves and a musty smell.

Mountain Ash

Water deeply when the topsoil feels dry to the touch. Avoid overwatering, which can lead to root rot. During the growing season, water more frequently. Reduce watering in the fall and winter. Signs of underwatering include wilting leaves and dry soil. Overwatering signs include yellowing leaves and soggy soil.

🌡️ Temperature & Humidity

Comfrey

Temperature: 10-25°C

Humidity: 30-50%

Mountain Ash

Temperature: 10-24°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Comfrey

Comfrey

Symphytum officinale
Care: Expert Time: 10 minutes weekly (mostly weeding and watering) Beginner: No

Experienced gardeners looking for a low-maintenance, fast-growing ground cover in a large outdoor space, understanding the toxicity risks.

✅ Choose This Plant If...

  • You have a large outdoor space and need a fast-growing ground cover.
  • You are interested in attracting pollinators to your garden.
  • You are an experienced gardener familiar with the plant's toxicity.
  • You want a low-maintenance plant that can tolerate a wide range of soil conditions.
  • You appreciate plants with a rich history of traditional use (though not for internal consumption).

❌ Skip This Plant If...

  • You have pets or small children who might ingest the plant.
  • You have limited space, as comfrey spreads aggressively.
  • You are looking for an easy-to-grow indoor plant.
📍 Ideal Location: Outdoor garden or meadow with full sun to partial shade.
🎨 Style: Cottage garden, Naturalistic
🏠 Apartment Friendly: No
⚠️ Comfrey contains pyrrolizidine alkaloids (PAs), which are toxic to dogs, cats, and horses. Symptoms include liver damage, vomiting, diarrhea, and abdominal pain. All parts of the plant are toxic, but the roots contain the highest concentration of PAs.
Mountain Ash

Mountain Ash

Sorbus aucuparia
Care: Expert Time: 30 minutes monthly (pruning, fertilizing, pest control) Beginner: No

Gardeners with outdoor space who want an ornamental tree that attracts birds.

✅ Choose This Plant If...

  • You have ample outdoor space and want a beautiful ornamental tree.
  • You want to attract birds to your garden.
  • You appreciate the vibrant colors of the berries in the fall.
  • You are experienced with tree care and pruning.
  • You live in a climate with cold winters suitable for its dormancy.

❌ Skip This Plant If...

  • You live in an apartment or have limited outdoor space.
  • You are looking for an easy-to-care-for indoor plant.
  • You have pets that might ingest the toxic berries.
  • You live in a very warm climate without a cold winter.
  • You are not prepared to deal with potential pest and disease issues.
📍 Ideal Location: Outdoors in a sunny location with well-drained soil.
🎨 Style: Traditional, Cottage Garden
🏠 Apartment Friendly: No
⚠️ The berries contain compounds that can release cyanide when digested. Symptoms in pets include vomiting, diarrhea, abdominal pain, and potential cyanide poisoning. All parts of the plant, especially the berries, are toxic to dogs, cats, and horses.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

☀️

Comfrey needs full sun to partial shade, while Mountain Ash prefers full sun (at least 6 hours of direct sunlight per day).

📈

Comfrey has fast growth, while Mountain Ash grows moderate.

💡 Pro Tips For Comparing These Plants

Comfrey Care Tips

Comfrey is an outdoor plant that is very difficult to grow indoors due to its need for full sun and its aggressive growth habit. It spreads via rhizomes and requires a large space to thrive. Indoor cultivation is not recommended due to these challenges and the plant's toxicity.

  • Plant in a location where it can spread freely.
  • Water deeply but infrequently.
  • Avoid over-fertilizing.
  • Monitor for pests and diseases.
  • Be aware of the plant's toxicity and take precautions to prevent ingestion.
❄️ Winter: Comfrey is dormant in winter. Cut back foliage after it dies back. No watering or fertilizing is needed.
☀️ Summer: Water regularly during dry periods. Monitor for pests and diseases. Provide shade during the hottest part of the day in very hot climates.

Mountain Ash Care Tips

Mountain Ash is an outdoor tree that is extremely difficult to grow indoors. It requires full sun, well-drained soil, and a cold dormancy period. Indoor attempts are unlikely to succeed long-term. Maintaining proper humidity and preventing pests are also challenges.

  • Plant in well-drained soil to prevent root rot.
  • Prune regularly to maintain shape and remove dead wood.
  • Monitor for pests and diseases and treat promptly.
  • Fertilize in the spring with a balanced fertilizer.
  • Provide adequate water during dry periods.
❄️ Winter: Minimal watering is required during dormancy. Protect young trees from harsh winter winds. Mulch around the base of the tree to insulate the roots.
☀️ Summer: Water regularly during dry periods. Monitor for pests and diseases. Provide shade during extremely hot weather if the tree is young.

⚠️ Common Problems & Solutions — Plant Care Comparison

Comfrey

Common Issues: Powdery mildew, Rust, Slugs and snails
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. | Rust: Remove infected leaves and apply a fungicide. | Slugs and snails: Use slug bait or handpick them off the plants.

Mountain Ash

Common Issues: Aphids, spider mites, fire blight, root rot
Solutions: Aphids and spider mites can be treated with insecticidal soap or neem oil. Fire blight requires pruning infected branches. Root rot is caused by overwatering; improve drainage and reduce watering frequency.

❓ Frequently Asked Questions — Comparing These Plants

Comfrey

What are the light requirements for Comfrey?

Comfrey thrives in partial to full sunlight, requiring at least 4-6 hours of direct sunlight per day for optimal growth and flowering. However, it can also tolerate partial shade, especially in hotter climates where intense afternoon sun can scorch its leaves. When grown in full sun, ensure adequate watering to prevent the soil from drying out.

How do I care for Comfrey?

Comfrey is relatively easy to care for. Plant in a location with partial to full sunlight, although it tolerates shade. Soil should be well-draining and fertile, but Comfrey is adaptable to various soil types. Water regularly, especially during dry periods, keeping the soil consistently moist but not waterlogged. Fertilize in spring with a balanced fertilizer to promote healthy growth and flowering.

How do I propagate Comfrey?

Comfrey is easily propagated through division, stem cuttings, or root cuttings.

Mountain Ash

What are the light requirements for Mountain Ash?

Mountain Ash thrives in bright, indirect light. Direct sunlight can scorch the delicate leaves, so avoid placing it in south-facing windows without some form of shading. An east- or west-facing window is ideal, providing ample light without the harshness of direct sun. If natural light is insufficient, supplement with a grow light to ensure healthy growth. Rotate the plant regularly to ensure even exposure to light on all sides. Insufficient light can lead to leggy growth and reduced vigor. Monitor the leaves for signs of sun scorch, such as browning or bleaching, and adjust the placement accordingly.

How do I care for Mountain Ash?

To successfully grow Mountain Ash indoors, provide bright, indirect light, avoiding direct sunlight which can scorch the leaves. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels, especially during winter when indoor air tends to be drier. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Repot every 2-3 years, or when the plant becomes root-bound, using a well-draining potting mix. Prune regularly to maintain shape and remove any dead or damaged branches. Protect from extreme temperatures and drafts. Monitor for pests and address promptly.

How do I propagate Mountain Ash?

Mountain Ash can be propagated through stem cuttings or air layering.

Last updated: April 30, 2026 — Plant care data reviewed and verified by our editorial team.