Rough Comfrey

symphytum asperum

Also known as: ["Asperum Comfrey","Prickly Comfrey"]

Family: Boraginaceae Genus: Symphytum Category: Herbs & Weeds

Overview

A hardy perennial herbaceous plant with rough, hairy leaves and bell-shaped flowers, native to parts of Asia and Eastern Europe.

Benefits & Perks

["disease resistant","cold hardy","wildlife attractant (bees, butterflies, birds)","medicinal use"]

Botanical Classification

Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Boraginales
Family: Boraginaceae
Genus: Symphytum
Botanical Name: Symphytum asperum

Plant Characteristics

Basic Information
  • Category: Herbs & Weeds
  • Suitable Location: garden bed in partial shade, or container in a sheltered spot
  • Suitable For:
    Collectors & Enthusiasts Outdoor Landscapers Wildlife Supporters
  • Is Weed: No
  • Allergenicity: low
Environmental Needs
  • Climate: {"temperatureRange":"5–30°C"}
  • Hardiness: {"zones":"4–8"}
  • Misting: rarely required, only if ambient humidity is very low
  • Drainage: Moderately well-draining; avoid waterlogged conditions.
  • Soil Type: Rich, loamy soil with good organic matter content.
Maintenance Level
  • Maintenance Level: moderate
  • Toughness Level: high
  • Pruning Frequency: As needed, typically in early spring before new growth begins.
  • Pruning Intensity: Light to moderate, focusing on removing only dead or overgrown parts.
Care Details

Ideal Sunlight Coverage:
Bright indirect light for 6–8 hours daily; tolerates partial shade, especially in hot climates.

Sunlight Tolerance Tips:
Acclimate gradually to intense light, protect from direct midday sun, and adjust placement based on seasonal light changes.

Warning Signs: Yellowing leaves, root rot, or stunted growth indicate poor soil conditions or improper watering.

Care Requirements

Care Difficulty
easy

moderate

Sunlight

partial shade to full sun

Rotate plant for even growth; use sheer curtains to filter intense light; avoid sudden light changes.

Watering

every 7–10 days during active growth, reduce in winter

Water thoroughly until it drains from the bottom, allow soil to dry between waterings, and avoid overwatering.

Soil

rich, moist, well-drained loam

pH: Slightly acidic to neutral (pH 6.0–7.0).

Ensure soil is not compacted; maintain consistent moisture; enrich with organic matter annually.

Temperature

Prefers 60–75°F (15–24°C); tolerates cooler temperatures but avoids frost.

Protect from frost; avoid sudden temperature swings; maintain moderate warmth.

Fertilizing

every 4–6 weeks during spring and summer

Apply fertilizer after watering to prevent root burn; stop feeding in winter; flush soil occasionally to prevent salt buildup.

Propagation

Methods

Stem cuttings or division of root clumps.

Step-by-Step Propagation Guide
  1. Take cuttings or divide roots, prepare medium, apply hormone (optional), plant, maintain humidity, and wait for roots.

Best Time: Early spring or late summer when the plant is actively growing.

Environment

Warm, humid environment with indirect light.

Medium

Well-draining potting mix with perlite or sand.

Hormone

Optional, but rooting hormone can speed up root development.

Timeline

Roots develop in 3–6 weeks; new growth appears in 2–3 months.

Tools Needed

Pruning shears, rooting hormone, pots, well-draining soil.

Quick Tips

Use healthy, non-flowering stems for cuttings; keep soil consistently moist but not waterlogged.

Pruning & Repotting

Pruning Guide
Method

Cut back stems to a healthy bud or leaf junction, thin out crowded areas.

Pruning Plan

Remove dead or damaged growth to encourage healthy development and maintain shape.

Tools

Pruning shears, sterilized knife.

Checklist

Sterilize tools, prune dead/damaged growth, shape plant, clean up debris.

Repotting Guide
Best Season

Early spring before active growth starts.

Pot Size

Choose a pot 1–2 inches larger in diameter than the current one.

Method

Remove plant gently, trim roots if needed, place in new pot with fresh soil, water lightly.

Suggestions

Repot every 2–3 years or when roots fill the pot; beneficial for growth and soil freshness.

Checklist

Select new pot, prepare soil, inspect roots, repot carefully, water lightly, place in appropriate light.

Advanced Care Tips

Watering Mastery
Watering Checklist

Check soil moisture, water deeply, ensure drainage, adjust for season.

How to Apply Water Properly

Water directly at the root zone, ensure even moisture distribution, allow excess water to drain, and water in the morning to reduce evaporation.

Pro Tip: Use a watering can with a narrow spout to target the base of the plant.
Watering Schedule Tips

Water deeply when the top 1–2 inches of soil are dry; reduce frequency in winter to prevent root rot.

Soil Improvement

Add compost or well-rotted manure for fertility; mix in perlite or sand for drainage.

Temperature Stress Management
Signs of Temperature Issues

Wilting, yellowing leaves, stunted growth, or leaf drop.

Cold Stress

Slows growth, may cause leaf discoloration, and can lead to root damage in freezing conditions.

Solution: Move to a warmer location, insulate pots, and avoid cold drafts.

Hot Stress

Leaf scorch, wilting, and reduced vigor due to excessive heat.

Solution: Provide shade, increase humidity, and water more frequently during heatwaves.

Fertilizing Guide
Fertilizing Checklist

Use diluted fertilizer, apply during active growth, avoid winter feeding, flush soil periodically.

Fertilizing Method

Use balanced liquid fertilizer diluted to half strength every 4–6 weeks during growing season (spring to early fall); avoid winter feeding.

Common Problems & Solutions

Yellowing leaves in Symphytum asperum may indicate nutrient deficiencies, overwatering, or pest infestations such as aphids or spider mites. It can also result from environmental stress, such as excessive sunlight or poor soil drainage.

Wilting in Symphytum asperum is often a sign of water stress, either due to under or overwatering. It can also be caused by root rot or damage from pests like nematodes, which impair the plant's ability to absorb water.

Leaf spots on Symphytum asperum are commonly caused by fungal or bacterial infections, leading to unsightly lesions on the foliage. Severe infections can cause premature leaf drop and reduce the plant's overall health.

Rotting in Symphytum asperum is typically caused by fungal infections or bacterial pathogens, often exacerbated by overwatering and poor soil drainage. This can lead to the decay of roots, stems, or leaves, ultimately killing the plant if left untreated.

Toxicity Warning

Cats
Toxic

Symphytum asperum is toxic to cats due to its pyrrolizidine alkaloid content, which can lead to severe liver damage and failure.

⚠️ Symptoms:
vomiting lethargy anorexia jaundice abdominal pain
🌿 Toxic Parts:
leaves stems roots flowers
⚡ Toxic If:

if eaten

Ensure cats cannot access the plant. Contact a veterinarian if ingestion is suspected.
Dogs
Toxic

The pyrrolizidine alkaloids in Symphytum asperum are toxic to dogs, causing liver toxicity and potential liver failure with chronic exposure.

⚠️ Symptoms:
vomiting lethargy loss of appetite jaundice abdominal pain
🌿 Toxic Parts:
leaves stems roots flowers
⚡ Toxic If:

if eaten

Keep plants out of reach of dogs. If ingestion is suspected, seek veterinary attention immediately.
Humans
Toxic

Symphytum asperum contains pyrrolizidine alkaloids, which are hepatotoxic and can cause liver damage upon ingestion. Chronic exposure may lead to severe liver fibrosis and even cirrhosis.

⚠️ Symptoms:
nausea vomiting abdominal pain jaundice liver damage
🌿 Toxic Parts:
leaves stems roots flowers
⚡ Toxic If:

if eaten

Avoid ingestion. Keep away from food preparation areas and ensure proper disposal of plant material.
Important: Keep this plant out of reach of children and pets. If ingestion occurs, contact poison control or veterinary services immediately.

Frequently Asked Questions

Q: Is Symphytum asperum toxic to humans?

A: Yes, it is toxic if ingested.

Q: Does Rough Comfrey attract wildlife?

A: Yes, it attracts bees, butterflies, and birds.

Q: What are the common uses of Symphytum asperum?

A: It is primarily used for medicinal purposes, such as topical treatments for wounds and bruises.

Quick Reference
Family: Boraginaceae
Care: easy
Light: partial shade to full sun
Water: every 7–10 days during activ
Suitable For: ["collectors/enthusiasts","outdoor landscapers","wildlife supporters (attracts bees, butterflies, birds)"]
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