Comfrey Symphytum officinale

☠ Toxic to humans
🐾 Toxic to pets
🌸 Not blooming
🍪 Not edible
‍🌱 Easy-care
common comfrey


Symphytum officinale, commonly known as comfrey, is a perennial plant with a deep, black root system and hairy, broad leaves. Its leaves are lance-shaped and progressively decrease in size as they ascend the stem. The plant blooms between late spring and early summer, displaying clusters of bell-shaped flowers that range in color from creamy white to pink and vivid purple. These hanging flowers provide a stark contrast to the dark green foliage. The comfrey's foliage is rough to the touch and covered in coarse hairs, giving it a somewhat bristly feel. While the leaves at the base of the plant are broad and large, those on the upper parts of the flowering stems are narrow and smaller. It's important to note that comfrey is widely recognized for its traditional use in herbal medicine.

Plant Info
Common Problems

About this plant

  • memoNames

    • Synonyms

      Common Comfrey, Knitbone, Quaker Comfrey, Boneset, Slippery Root, Healing Herb, Consound, Blackwort, Bruisewort, Knitback, Salsify, Wallwort.

    • Common names

      Symphytum officinale L., Symphytum officinale var. bohemicum F.W.Schmidt, Symphytum officinale var. patens (W.D.J.Koch) Celak., Symphytum patens W.D.J.Koch, Symphytum uliginosum A.Kern., Symphytum uliginosum var. majus Beck, Symphytum uliginosum var. spurium Beck, Symphytum spurium (Beck) Nyman, Symphytum officinale subsp. bohemicum (F.W.Schmidt) Čelak.

  • skullToxicity

    • To humans

      Comfrey (Symphytum officinale) contains toxic pyrrolizidine alkaloids (PAs) which can cause liver damage and are also carcinogenic. The ingestion of comfrey can lead to the blockage of small blood vessels in the liver, causing a condition known as veno-occlusive disease, which can result in liver cirrhosis and liver failure. Symptoms of poisoning may include nausea, vomiting, abdominal pain, and in severe cases, it can lead to hepatotoxicity and hepatic failure. It must be noted that the application of comfrey on skin is considered much less risky than ingestion, but should still be done with caution, especially on open wounds.

    • To pets

      Comfrey (Symphytum officinale) is also toxic to pets due to the same pyrrolizidine alkaloids found in the plant. These compounds can cause similar liver damage in animals as in humans. Symptoms in pets might include gastrointestinal upset, such as vomiting and diarrhea, and with long-term ingestion can lead to liver failure. Pet owners should prevent their animals from consuming any part of the comfrey plant to avoid the risk of poisoning.

  • infoCharacteristics

    • Life cycle


    • Foliage type


    • Color of leaves


    • Flower color


    • Height

      2-3 feet (0.6-0.9 meters)

    • Spread

      1 foot (0.3 meters)

    • Plant type


    • Hardiness zones


    • Native area

      Europe Asia


  • money-bagGeneral Benefits

    • Soil Improvement - Symphytum officinale, commonly known as comfrey, has deep roots that mine the subsoil for minerals, potentially improving soil fertility.
    • Compost Activator - Comfrey leaves decompose quickly and can be added to compost piles to accelerate the breakdown of organic matter.
    • Plant Fertilizer - Due to its high potassium content, comfrey can be used to make a liquid plant fertilizer to promote healthy growth in other plants.
    • Livestock Feed - Comfrey is sometimes used as a feed for livestock because of its high protein content and palatability for animals like rabbits and chickens.
    • Dynamic Accumulator - As a dynamic accumulator, comfrey gathers nutrients from deep within the soil, making them accessible when its leaves are used as mulch or in compost.
    • Erosion Control - With its dense and robust root system, comfrey can help prevent soil erosion on steep banks and sloped gardens.
    • Pollinator Attraction - Comfrey flowers attract bees and other beneficial insects to the garden, enhancing pollination and biodiversity.
    • Mulching Material - Comfrey leaves can be used as a mulching material around plants to conserve moisture and suppress weeds.
    • Biodiversity Support - By providing a habitat for beneficial insects and microorganisms, comfrey plays a part in maintaining and enhancing biodiversity in the garden.

  • medicalMedical Properties

    • Wound healing: Comfrey (Symphytum officinale) is traditionally used for the topical treatment of wounds, ulcers, and insect bites due to its content of allantoin, which may promote cell proliferation and repair of the skin.
    • Anti-inflammatory properties: The plant has been used to reduce inflammation, particularly in cases of sprains and broken bones.
    • Pain relief: Comfrey preparations are sometimes applied to the skin to alleviate pain associated with muscle and joint issues, like back pain or sprains.
    • Treatment of bruises: Topically applied, comfrey could be beneficial in reducing bruising and tissue damage.
    • Skin conditions: Comfrey may be applied to the skin for managing conditions such as dermatitis, eczema, or psoriasis due to its moisturizing and reparative qualities.
    • Respiratory health: Historically, it was used for treating respiratory problems when ingested, though internal use is now discouraged due to the presence of toxic pyrrolizidine alkaloids.

  • windAir-purifying Qualities

    This plant is not specifically known for air purifying qualities.

  • leavesOther Uses

    • Comfrey leaves are sometimes used as a natural fertilizer in gardens due to their high content of nitrogen, potassium, and phosphorus.
    • The slimy substance from comfrey roots can be used as a natural form of glue or paste.
    • Comfrey has traditionally been used to condition soil and speed up the decomposition process in compost heaps thanks to its fast decay when chopped and mixed into the pile.
    • As a dynamic accumulator, comfrey's deep roots can bring up nutrients from the subsoil, which can then be used to nourish other plants when its leaves are used as mulch.
    • Some gardeners create a 'comfrey tea' by steeping the leaves in water, which is then used as a nutrient-rich liquid fertilizer for plants.
    • The fibrous stems of comfrey have been experimented with for making rough paper or cardboard products.
    • Comfrey leaves have been used as a green dye for fabrics, although this is not a commonly practiced technique.
    • Farmers have used comfrey in the past as feed for livestock, although it is not widespread and care must be taken due to certain compounds that can be harmful in large quantities.
    • In permaculture, comfrey plants are often planted along the edges of garden beds to act as a living barrier and to prevent the encroachment of grass and weeds.
    • Historically, comfrey was sometimes used to fill in potholes or line the bottoms of primitive roads and pathways to create a more stable walking surface.

Interesting Facts

  • bedFeng Shui

    The plant Comfrey is not used in Feng Shui practice.

  • aquariusZodiac Sign Compitability

    The plant Comfrey is not used in astrology practice.

  • spiralPlant Symbolism

    • Healing: Symphytum officinale, commonly known as comfrey, has long been associated with healing due to its medicinal properties that help in repairing bones and healing wounds.
    • Protection: Comfrey is also considered to represent protection, as it was historically used to protect travelers and ward off harmful or negative influences.
    • Safety During Travel: Carrying comfrey or using products made from it was believed to ensure a safe journey, particularly for those traveling long distances.
    • Fertility: Being a plant that vigorously grows and replenishes, comfrey is symbolic of fertility and the abundance of nature.

Every 1-2 weeks
2500 - 10000 Lux
Every year
Spring-Early Summer
Not needed
  • water dropWater

    Comfrey (Symphytum officinale) prefers consistent moisture, so water it deeply once a week, providing about 1-2 gallons per square yard of soil. During particularly hot or dry weather, you may need to water twice a week. Ensure the soil is well-draining to prevent waterlogging. Adjust the frequency to maintain moist soil, being cautious not to overwater as comfrey does not like to sit in soggy soil.

  • sunLight

    Comfrey thrives in full sun to partial shade. The best location for comfrey would be a spot that receives morning sun and afternoon shade, or dappled sunlight throughout the day. This plant is quite adaptable, though, and can perform well even in areas that only receive partial sunlight.

  • thermometerTemperature

    Comfrey is hardy and can tolerate a wide range of temperatures, typically surviving in conditions as cold as 50°F and as hot as 85°F. Its ideal growing temperatures are between 55°F and 75°F. It can survive light frosts but sustained temperatures below freezing may damage or kill the plant.

  • scissorsPruning

    Pruning comfrey is usually done to control its size and spread, and to remove any damaged or diseased leaves. It's best pruned back in the fall or early spring. If you harvest the leaves for comfrey's medicinal properties, you may prune several times during the growing season by cutting leaves just above the base of the plant.

  • broomCleaning

    As needed

  • bambooSoil

    Comfrey (Symphytum officinale) thrives in moist, well-draining soil with a pH ranging from 6.0 to 7.0. An ideal soil mix can be made from equal parts of garden soil, compost, and peat or sand to ensure adequate drainage.

  • plantRepotting

    Comfrey plants, being perennial and often large, do not require frequent repotting and can be left undisturbed for several years. They are typically repotted only when the plant outgrows its current container or when the soil needs replenishment.

  • water dropsHumidity & Misting

    Comfrey plants prefer a moderate level of humidity, typical of outdoor conditions. They are not particularly sensitive to humidity levels, making them tolerant of the varying humidity found in most gardens and outdoor environments.

  • pinSuitable locations

    • Indoor

      Plant comfrey in a large container, with well-drained soil, in a sunny spot.

    • Outdoor

      Plant in well-drained soil, full to partial sun, water regularly.

    • Hardiness zone

      3-9 USDA

  • circleLife cycle

    Symphytum officinale, commonly known as comfrey, begins its life cycle when seeds germinate in the soil in spring, requiring moisture and a bit of light to sprout. Seedlings grow into rosettes of fuzzy, oblong leaves that can withstand cold temperatures. As the plant matures, it develops a deep taproot and erect, branching stems that can reach up to 1-3 feet in height. In late spring to early summer, comfrey blooms with clusters of bell-shaped flowers, typically purple, pink, or white, which are pollinated by bees. After pollination, seeds form and are dispersed by wind or water. Comfrey is also a perennial, capable of resprouting from its rootstock each year, and can also spread vegetatively through root cuttings.

  • sproutPropogation

    • Propogation time

      Spring-Early Summer

    • Propogation: Comfrey (Symphytum officinale) is most popularly propagated through root division. This method is typically undertaken in the early spring or fall, when the plant is not actively flowering. To propagate by division, gardeners dig up a healthy comfrey plant and carefully split the root ball into smaller sections, ensuring that each section has a piece of the root and a few shoots. These segments are then replanted in the soil, spaced about 24 to 30 inches (approximately 61 to 76 centimeters) apart to allow for ample growth. Roots should be planted no deeper than 2 inches (5 centimeters) into the soil to encourage successful establishment of the new plants. The soil should be well-draining and rich in organic matter to facilitate the best growth of the comfrey shoots. Once established, comfrey plants can spread and become quite prolific.