Comfrey Symphytum tuberosum
ABOUT
Symphytum tuberosum, commonly known as tuberous comfrey, is a perennial plant that has a robust and somewhat bushy appearance. This plant features a clump of hairy, oblong leaves that sprout from its base, providing a dense green backdrop. The leaves are typically dark green and may feel slightly rough to the touch, with distinctive veining patterns that can be observed upon closer inspection. As spring arrives, tuberous comfrey showcases its charm through bell-shaped flowers that dangle in clusters from arched stems. The colors of these blossoms can vary from creamy yellow to a soft ivory, creating a subtle contrast against the lush foliage. The flowers are favored by bees and other pollinators, which are drawn to their nectar-rich depths. While in bloom, the tuberous comfrey plants impart a gentle aesthetic to garden spaces, with their nodding flowers adding a touch of whimsy. Despite being known for its underground tubers, the visible parts of the plant are what draw attention and provide aesthetic value to the landscapes they inhabit. When not in flower, the plant's foliage continues to offer a green, textural presence in the garden throughout the growing season.
About this plant
NamesSynonyms
Tuberous Comfrey, Knitbone, Healing Herb, Blackwort, Bruisewort, Slippery Root, Boneset.
Common names
Symphytum bulbosum K.F.Schimp., Symphytum tuberosum subsp. angustifolium Nyman, Symphytum tuberosum subsp. tuberosum, Symphytum peregrinum Ledeb.
ToxicityTo humans
Symphytum tuberosum, commonly known as tuberous comfrey, contains pyrrolizidine alkaloids, which are toxic to humans. Ingesting any part of the plant can lead to pyrrolizidine alkaloid poisoning. Symptoms of this poisoning can vary but typically include liver damage, which may progress to liver failure. Other symptoms can include digestive disturbances, progressive weakness, and ascites due to liver cirrhosis. Chronic exposure to these toxins may also increase the risk of liver cancer. Since the toxicity is cumulative, even small, repeated doses can be harmful over time.
To pets
Tuberous comfrey's toxicity to pets stems from the same pyrrolizidine alkaloids that make it dangerous to humans. If pets ingest any part of the plant, they can suffer from liver damage, which can manifest as lethargy, jaundice, abdominal fluid accumulation, and potentially, hepatic encephalopathy. These symptoms might not appear immediately as the toxins can have a cumulative effect, leading to chronic liver dysfunction or failure over time. Pet owners should prevent their animals from chewing on or consuming this plant.
CharacteristicsLife cycle
Perennials
Foliage type
Deciduous
Color of leaves
Green
Flower color
Yellow
Height
1-2 feet (30-60 cm)
Spread
1 feet (30 cm)
Plant type
Herb
Hardiness zones
4
Native area
Europe
Benefits
General Benefits- Soil improvement: Symphytum tuberosum, commonly known as tuberous comfrey, has deep roots that help to aerate the soil and bring up nutrients from the deeper layers, making them available to other plants.
- Composting: Tuberous comfrey leaves decompose quickly and can be added to compost piles to help accelerate the breakdown of organic material and enrich the compost with nutrients.
- Natural fertilizer: The leaves of tuberous comfrey are high in nitrogen, phosphorus, and potassium, which are essential nutrients for plant growth, making it an excellent natural fertilizer when used as a mulch or in liquid plant feeds.
- Wildlife habitat: The flowers of tuberous comfrey attract bees, beneficial insects, and other pollinators, providing an essential habitat and food source to support biodiversity in the garden.
- Livestock feed: The leaves of tuberous comfrey can be used as a supplemental food source for livestock, as they are rich in protein and minerals.
Medical Properties- Wound healing: Symphytum tuberosum, commonly known as Comfrey, contains allantoin which is thought to stimulate cell proliferation and promote wound healing.
- Anti-inflammatory action: Due to the presence of rosmarinic acid, Comfrey may have anti-inflammatory properties useful in reducing swelling and treating bruises.
- Pain relief: Traditionally, Comfrey has been used to alleviate pain from sprains, strains, and osteoarthritis through topical application.
- Skin health: Comfrey's mucilage content can provide moisturizing benefits to the skin, potentially aiding in the treatment of eczema and other skin irritations.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Symphytum tuberosum, commonly known as tuberous comfrey, can be used as a compost activator due to its high nitrogen content, which helps speed up the decomposition process.
- The leaves of tuberous comfrey are rich in nutrients, making them an excellent addition to mulches or green manures in the garden.
- The plant can be used as an organic fertilizer, with the leaves steeped in water to make a nutrient-rich "comfrey tea" for plants.
- Tuberous comfrey's deep roots bring up minerals from the subsoil, which can be recycled onto the soil surface when the plant is cut and left to decompose.
- The fibrous stems of the plant have been historically used for making rough textiles or twine, albeit not commonly in modern times.
- As an exceptionally fast-growing plant, tuberous comfrey can be used for erosion control, establishing root systems that help stabilize the soil.
- The dense foliage of the plant provides habitat and shelter for beneficial insects, supporting biodiversity in the garden.
- When planted along the borders of a vegetable patch, tuberous comfrey can act as a trap crop, potentially luring slugs away from more valuable plants.
- The high mucilage content of the leaves can make it a useful ingredient in creating plant-based thickeners or emulsifiers for culinary purposes.
- Comfrey plants are sometimes used in orchards under fruit trees to provide a natural mulch and gradual release of nutrients to the trees.
Interesting Facts
Feng ShuiThe Comfrey is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Comfrey is not used in astrology practice.
Plant Symbolism- Healing - Symphytum tuberosum, commonly known as Comfrey, has been used medicinally for centuries, symbolizing healing and the mending of wounds due to its chemical properties that can help in skin regeneration and reduce inflammation.
- Protection - Comfrey is also believed to symbolize protection, as it was traditionally used to protect the skin and help heal bruises and sprains.
- Money - In folklore, Comfrey was thought to attract money and good fortune, likely because its rapid growth was associated with prosperity.
- Safety During Travel - The roots of Comfrey were sometimes carried by travelers for safety, representing safe journeys and protection from mishaps on the road.
WaterTubers comfrey (Symphytum tuberosum) should be watered deeply and less frequently to encourage strong root growth. Generally, during the growing season, watering once a week with 1 gallon of water per plant should suffice, unless there are periods of drought or extreme heat, which may necessitate a slight increase in watering frequency. It's important to allow the soil to dry out partially between waterings to prevent root rot. During the winter when the plant is dormant, reduce watering significantly and only water to prevent the soil from completely drying out.
LightFor tuberous comfrey, the best light conditions include full sun to partial shade. Ideally, it should receive at least four hours of direct sunlight daily. An optimal spot would be one where the plant is exposed to morning sun and protected from the intense afternoon heat, especially in hotter climates.
TemperatureTuberous comfrey prefers a temperate climate and can survive in temperatures ranging from 50°F to 77°F. The minimum temperature it can tolerate is around 40°F, while the maximum temperature should not exceed 85°F. The ideal temperature range for its growth is between 55°F and 75°F.
PruningTuberous comfrey should be pruned to remove dead or yellowing leaves and to shape the plant if desired. Pruning can be done in early spring or after flowering to encourage a second bloom or to maintain plant size. Cut back the plant to about 6 inches above the ground every few years to rejuvenate and stimulate new growth.
CleaningAs needed
SoilFor Symphytum officinale, commonly known as comfrey, the best soil mix is rich, well-draining loam with added organic matter such as compost. The soil pH should ideally be between 6.0 and 7.0.
RepottingComfrey, or Symphytum officinale, does not need to be repotted frequently; it can be done every 2-3 years or when the plant outgrows its container.
Humidity & MistingSymphytum officinale, known as comfrey, prefers moderate humidity but is quite adaptable to varying humidity levels.
Suitable locationsIndoor
Place comfrey in a well-lit spot with indirect sunlight.
Outdoor
Plant comfrey in partial shade; keep soil moist.
Hardiness zone
4-9 USDA
Life cycleSymphytum tuberosum, commonly known as Tuberous Comfrey, begins its life cycle as a seed that germinates in moist soil during spring. Seedlings emerge and develop into a rosette of hairy leaves, with the plant favoring partial shade conditions. As it matures, Tuberous Comfrey develops a thick root system that can propagate asexually through root cuttings. By late spring to early summer, it produces small bell-shaped cream or pale yellow flowers on coiled cymes, which are pollinated by bees. Following pollination, the plant sets seed, which can be dispersed by wind or animals, ensuring the proliferation of the next generation. During winter, the foliage dies back to the ground, with the plant surviving as a tuberous root, ready to regrow the following spring.
PropogationPropogation time
Spring to early summer
Propogation: Comfrey (Symphytum tuberosum) is often propagated through root cuttings, and the best time to do this is in late winter to early spring when the plant is still dormant. To propagate comfrey using root cuttings, a segment of the root about 2-6 inches long (5-15 cm) is typically used. The root cutting should be planted horizontally in soil, at a depth of 2 inches (5 cm), and spaced about 12 inches (30 cm) apart. It's important to keep the soil moist until the cuttings are established. Once growth is evident, which usually takes a few weeks, the plants can be treated as mature comfrey plants. This method is popular among gardeners due to its high success rate and the speed at which new plants become established.
