Comfrey

Basic Information

Common Name: Comfrey

Scientific Name: Symphytum officinale

Native Habitat: Europe and Asia

History / Discovery / Cultivator

Comfrey, scientifically known as Symphytum officinale, boasts a rich history rooted in traditional medicine and agriculture. Its use dates back over 2000 years, with evidence suggesting its widespread application by the ancient Greeks and Romans. The name “Symphytum” itself derives from the Greek word “symphyo,” meaning “to unite” or “grow together,” alluding to the plant’s purported ability to heal wounds and mend broken bones. “Officinale,” the species epithet, indicates its historical inclusion in official pharmacopoeias, signifying its recognized medicinal value.

Comfrey’s origins are traced to Europe and parts of Asia, where it thrives in damp meadows, along riverbanks, and in other moist environments. Throughout the Middle Ages, comfrey was a staple in monastery gardens, cultivated for its medicinal properties. Monks played a crucial role in disseminating knowledge about its therapeutic applications, utilizing it in poultices, teas, and salves.

The plant’s popularity extended beyond the religious sphere, becoming a common fixture in household gardens and apothecaries across Europe. Herbalists such as Nicholas Culpeper, a renowned 17th-century English botanist and physician, extolled comfrey’s virtues, advocating its use for treating a wide array of ailments, ranging from bruises and sprains to ulcers and respiratory problems.

While not attributed to a single “discoverer,” the systematic study and documentation of comfrey’s properties by various herbalists, physicians, and botanists over centuries contributed to its recognition as a valuable medicinal plant. Its use as a poultice to speed bone healing became particularly well-known, earning it common names such as “knitbone.”

In more recent times, comfrey has been adopted by organic gardeners and permaculture enthusiasts for its beneficial properties in the garden. Its deep roots mine nutrients from the subsoil, and its leaves, when composted, create a nutrient-rich fertilizer. Comfrey is also a popular choice for creating “comfrey tea,” a liquid fertilizer that is highly beneficial to plants. While comfrey continues to be studied for its medicinal potential, internal use is generally discouraged due to the presence of pyrrolizidine alkaloids, which can be harmful to the liver. However, it remains a valuable plant for external applications and as a soil amendment in sustainable gardening practices. The lasting legacy of comfrey reflects its enduring appeal as a versatile plant with a rich history steeped in traditional knowledge and practical applications.

Plant Care Summary

Botanical Insights

Adaptations

Comfrey exhibits several interesting adaptations that contribute to its survival and propagation. Its deep taproot allows it to access water and nutrients deep within the soil, making it relatively drought-tolerant once established. The taproot also serves as a storage organ, enabling the plant to survive harsh winters and regenerate in the spring. Its hairy leaves and stems may offer some protection against herbivores. Furthermore, comfrey is a prolific seed producer and can also readily propagate vegetatively from root fragments, contributing to its ability to spread and colonize new areas. The ability of its roots to grow deeply into the soil allows it to pull nutrients from the subsoil and make them available to other plants when its leaves are used as mulch or composted, a crucial adaptation for its use as a dynamic accumulator in permaculture systems.

Propagation Methods

Comfrey can be propagated through several methods, including:

• Root Cuttings: This is the most common and reliable method. Dig up the plant and divide the roots into sections, ensuring each section has at least one growth bud. Plant the root cuttings horizontally about 2-3 inches deep.
• Division: Mature plants can be carefully divided at the root ball, ensuring each division has a healthy portion of roots and foliage.
• Seed: While possible, propagation from seed can be slow and germination rates may be variable. Seeds should be sown in early spring.
• Crown Cuttings: Take cuttings from the crown of the plant in early spring. These cuttings can be rooted in a well-draining potting mix.

Toxicology

Comfrey contains pyrrolizidine alkaloids (PAs), which are toxic compounds that can cause liver damage (veno-occlusive disease) if ingested. The risk is particularly high with prolonged or high-dose consumption. While the concentration of PAs varies depending on the species and growing conditions, internal use of comfrey is generally discouraged by health authorities. Symptoms of PA toxicity can include abdominal pain, jaundice, fatigue, and in severe cases, liver failure. While external use has a much lower risk, it’s best to avoid using it on broken skin or open wounds, especially for pregnant or breastfeeding women and individuals with pre-existing liver conditions. Pets, especially dogs and cats, should not be allowed to ingest comfrey. Symptoms in pets can mirror those in humans, including vomiting, lethargy, and abdominal swelling.

Common Problems

Pests:

• Slugs and snails
• Aphids
• Spider mites

Diseases:

• Powdery mildew
• Rust
• Leaf spot

Other:

• Leaf yellowing (due to nutrient deficiency, especially nitrogen)
• Stunted growth (due to poor soil conditions or lack of sunlight)
• Overgrowth (can become invasive if not managed)

Rarity & Value

Rarity:

Comfrey is not generally considered a rare plant. It is widely cultivated and naturalized in many regions. However, specific cultivars, such as those with unique leaf variegation or improved medicinal properties, might be less common and therefore more sought after. The Bocking 14 cultivar, known for its high biomass production and low PA content, is also desirable.

Value:

The value of comfrey plants is generally low, reflecting its availability and ease of propagation. However, factors that can increase its value include:

• Cultivar: Specific cultivars with desirable traits (e.g., Bocking 14) may command a slightly higher price.
• Plant Size: Larger, more established plants are often more valuable than seedlings.
• Organic Certification: Plants grown organically may be preferred by some buyers.
• Medicinal Use: The perceived medicinal value can increase its desirability, although this is tempered by concerns about toxicity.